Switching control circuit, intelligent switch and switching control method

Abstract

This application provides a switch control circuit, a smart switch, and a switch control method. The switch control circuit includes: a transformer circuit connected to a rectifier circuit, used to provide power to a power supply via a rectified electrical signal output from the rectifier circuit; wherein the transformer circuit includes a primary-side input unit and a secondary-side output unit, wherein the primary-side input unit is connected to the rectifier circuit; a power management circuit, at least connected to the primary-side input unit, used to acquire a first sampling signal reflecting the power supply during the switch circuit's off-state, and control the current flowing through the primary-side input unit based on the first sampling signal to stabilize the power supply provided by the secondary-side output unit; and used to continuously provide power to the power supply via a rectified electrical signal during the switch circuit's on-state; and a control circuit, supported by the power supply, used to control the switch circuit to turn on or off upon receiving a control information. This application achieves the purpose of providing internal power supply during both the off-state and on-state of the switch circuit.

Description

Technical Field

[0001] This application relates to the field of circuit control technology, and in particular to a switch control circuit, an intelligent switch, and a switch control method. Background Technology

[0002] Smart home appliances are home appliances that incorporate microprocessor, sensor, and network communication technologies. They are characterized by automatically sensing the status of the living space, the appliance's own status, and the appliance's service status. They can automatically control and receive control information from home users, either inside or remotely. Furthermore, as a component of smart homes, smart home appliances can interconnect with other home appliances, furniture, and facilities within the home to form a system and realize smart home functions.

[0003] Currently, common remote control devices for smart home appliances, such as universal remote controls and mobile terminals, all use integrated control information to control the appliances. They do not involve the wiring of the smart appliances, thus allowing them to have a standby mode to process received control information promptly. With the increasing variety of smart home appliances, a panel-type smart switch has emerged that integrates the control and management of both smart and traditional appliances. This overcomes the limitation of remote controls in controlling traditional appliances, but it also introduces new internal power supply issues. Summary of the Invention

[0004] In view of the shortcomings of the prior art described above, the purpose of this application is to provide a switch control circuit, a smart switch, and a switch control method to solve the power supply problem of the smart switch during the working and non-working periods of the electrical appliances controlled by the smart switch in the prior art.

[0005] To achieve the above and other related objectives, a first aspect of this application provides a switch control circuit for controlling a switch circuit connected to a line loop containing a load. The switch control circuit includes: a transformer circuit connected to a rectifier circuit for supplying power to a power supply via a rectified electrical signal output by the rectifier circuit; wherein the transformer circuit includes a primary-side input unit and a secondary-side output unit, wherein the primary-side input unit is connected to the rectifier circuit; a power management circuit connected at least to the primary-side input unit, wherein the power management circuit is configured to acquire a first sampling signal reflecting the power supply signal output by the power supply during the switch circuit's off-state, and control the current flowing through the primary-side input unit based on the first sampling signal to stabilize the power supply output by the secondary-side output unit; and to continuously supply power to the power supply via the rectified electrical signal during the switch circuit's on-state; and a control circuit, supported by the power supply, for controlling the switch circuit to turn on or off upon receiving a control message.

[0006] A second aspect of this application provides a smart switch for connecting to an AC power line containing a load. The smart switch includes: a switching circuit connected to the AC power line and controlled to be turned on or off; a rectifier circuit for rectifying the connected AC power and outputting a rectified signal during the off-state and on-state periods of the switching circuit, respectively; and a switch control circuit as described in any of the first aspects, connected to the rectifier circuit and controlling the switching circuit.

[0007] A third aspect of this application provides a switch control method for controlling a switch circuit connected to an AC power line with a load. The switch control method includes: during a period when the switch circuit is off, acquiring a first sampling signal reflecting the power supply provided by a secondary output unit of a transformer circuit, and controlling the current in the primary input unit of the transformer circuit based on the first sampling signal; wherein the transformer circuit supplies power to the power supply via a rectified signal provided by a rectifier circuit; during a period when the switch circuit is on, continuously supplying power to the power supply via the received rectified signal; and, with the power support of the power supply, a control circuit controls the switch circuit to be on or off upon receiving control information.

[0008] As described above, the switch control circuit, intelligent switch, and switch control method of this application have the following beneficial effects: they can provide internal power supply during both the open and closed periods of the switch circuit without requiring a separate AC power circuit. Furthermore, by detecting the zero-crossing phase of the AC power during the open and closed periods of the switch circuit, and using the generated zero-crossing detection signal to delay and control the switching operation of the switch circuit, the impact of the peak voltage range of the AC power on the load is effectively reduced, extending the load's service life. Attached Figure Description

[0009] Figure 1 The diagram shown is a schematic diagram of the circuit framework of the switch control circuit in one embodiment of this application.

[0010] Figure 2 The diagram shown is a schematic diagram of the circuit structure of the switch control circuit in one embodiment of this application.

[0011] Figure 3 The diagram shown is a schematic diagram of the circuit structure of the switch control circuit in one embodiment of this application.

[0012] Figure 4 The diagram shows a frame structure of the switch control circuit in another embodiment of this application.

[0013] Figure 5 The diagram shown is a schematic diagram of the circuit structure of the switch control circuit in another embodiment of this application.

[0014] Figure 6 The diagram shown is a schematic diagram of the circuit structure of the switch control circuit in one embodiment of this application.

[0015] Figure 7 Displayed as Figure 6 Waveform diagram of a circuit node.

[0016] Figure 8 The diagram shown is a schematic diagram of the circuit structure of the first zero-crossing detection unit in this application.

[0017] Figure 9 The diagram shown is a schematic diagram of the circuit structure of the second zero-crossing detection unit in one embodiment of this application.

[0018] Figure 10 The diagram shown is a schematic diagram of the zero-crossing detection circuit in this application.

[0019] Figure 11 The diagram shows a frame structure of the smart switch in one embodiment of this application.

[0020] Figure 12 The diagram shows a circuit structure of the smart switch in one embodiment of this application.

[0021] Figure 13 The diagram shown is a schematic diagram of the circuit structure of the smart switch in one embodiment of this application.

[0022] Figure 14 The flowchart shown is a process for controlling the switch during the disconnection period of the switch circuit in this application.

[0023] Figure 15 The flowchart shown is a process for controlling the switch during the conduction period of the switch circuit in this application.

[0024] Figure 16 The diagram shown is a schematic diagram of the circuit structure of the control unit in one embodiment of the switch control circuit of this application.

[0025] Figure 17 The diagram shown is a circuit structure diagram of the control unit in another embodiment of the switch control circuit of this application.

[0026] Figure 18 The diagram shown is a schematic diagram of the circuit structure of the control unit in the switch control circuit of this application in another embodiment.

[0027] Figure 19 The diagram shown is a structural schematic of the power supply unit in another embodiment of the switch control circuit of this application.

[0028] Figure 20The diagram shows a schematic representation of the zero-crossing detection circuit in one embodiment. Detailed Implementation

[0029] The following specific embodiments illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification.

[0030] While the terms first, second, etc., are used in some instances herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, a first preset threshold may be referred to as a second preset threshold, and similarly, a second preset threshold may be referred to as a first preset threshold, without departing from the scope of the various described embodiments. Both the first preset threshold and the preset threshold describe a threshold, but they are not the same preset threshold unless the context explicitly indicates otherwise. A similar situation includes first volume and second volume.

[0031] Furthermore, as used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context indicates otherwise. It should be further understood that the terms “comprising,” “including,” indicate the presence of the stated feature, step, operation, element, component, item, kind, and / or group, but do not preclude the presence, occurrence, or addition of one or more other features, steps, operations, elements, components, items, kinds, and / or groups. The terms “or” and “and / or” as used herein are to be interpreted inclusively, or mean any one or any combination thereof. Thus, “A, B, or C” or “A, B, and / or C” means “any one of: A; B; C; A and B; A and C; B and C; A, B, and C.” Exceptions to this definition occur only when combinations of elements, functions, steps, or operations are inherently mutually exclusive in some way.

[0032] To handle various smart and traditional home appliances, the smart switch must be compatible with both the switch-type control circuit of traditional home appliances (which can correspond to the control circuits mentioned below) and the logic control circuit of smart home appliances. The switch-type control circuit includes a switch circuit and a control circuit for that switch circuit. Examples of switch circuits include relays (or power transistors, etc.) and drivers. Examples of control circuits for the switch circuit include control circuits for adjusting at least one of the following: on-time, off-time, and on / off frequency. The logic control circuit refers to controlling the corresponding electronic device through indications in control information, causing the electronic device to switch to the corresponding operating state according to the indicated content. The control information includes, but is not limited to, at least one of the following: on / off information, temperature information, duration information, timing information, mode information, location information, brightness information, and other indications that can be recognized by smart home appliances. The logic control circuit includes, but is not limited to, a processor, a signal transceiver, and external circuits. Examples of processors include CPUs, FPGAs, MCUs, or chips integrating any of the example processors. The signal transceiver device includes, but is not limited to: short-range communication modules such as RF communication modules, WiFi communication modules, infrared communication modules, and Bluetooth communication modules; communication modules that can access wide area networks such as fiber optics and broadband; and communication modules that use a SIM card to access mobile networks. The external circuits include, but are not limited to: power supply circuits for providing operating power to the processor, signal transceiver device, etc., and other peripheral circuits. These other peripheral circuits include, but are not limited to, at least one of the following: a first circuit not integrated into the chip that can provide a preset electrical signal to the chip, wherein the electrical signal provided by the first circuit includes, for example, a sampling signal; and a second circuit for processing the electrical signal output by the chip, wherein the second circuit, for example, modulates, divides, amplifies, filters, etc., the electrical signal output by the chip.

[0033] Because the logic control circuit inside a smart switch has difficulty obtaining the power to maintain operation when the switch-type control circuit is disconnected, smart switches typically use two separate circuits to achieve logic control and switch-type control. This results in a very low integration of the smart switch and also requires complex external wiring.

[0034] It should be noted that any of the above examples, as well as the AC wires, AC circuits, and AC circuits mentioned below, should be considered to include: wires required for connection to the city power grid, including neutral, live, and ground wires. For example, LED lights and smart switches connected to an AC wire can form a power circuit.

[0035] Therefore, this application provides a switch control circuit to solve the internal power supply problem of two control circuits in a smart switch. Here, the switch control circuit is a control circuit that can control both switch-type control circuits and logic control circuits, and it is powered by the AC power connected to the switch circuit. The switch circuit is used to control the on / off state of the load power supply circuit, and it is connected in series with the load between the neutral and live wires of the AC power supply. For example, the live wire connected to the residential power grid is sequentially connected to the switch circuit and the load, and the load is connected to the neutral wire of the power grid to form an AC power supply circuit. Alternatively, the live wire connected to the residential power grid is sequentially connected to the load and the switch circuit, and the switch circuit is connected to the neutral wire of the power grid to form an AC power supply circuit. The load can be a single load, or connected to the power supply circuit using a series, parallel, or combined series-parallel connection method. The switch circuit can be used to control the power supply of a single load, or configured on an AC power line shared by multiple loads to control the power supply of multiple loads. In some embodiments, multiple loads are provided, each load being connected in series with a switching circuit. The series-connected switching circuits and loads are connected in parallel with other series-connected switching circuits and loads and are connected to an AC power line to control the power supply of multiple loads.

[0036] In some examples, the load is a load circuit that internally includes a voltage (or current) conversion circuit, wherein the conversion circuit converts alternating current into a supply voltage (or supply current). When the supply voltage (or supply current) reaches the operating voltage (or operating current), the load enters the operating state; when the supply voltage (or supply current) does not reach the operating voltage (or operating current), the load exits the operating state. Examples of such loads include LED lights, electric curtains, and power adapters. Examples of such switching circuits include relays and relay controllers. Taking an LED light as the load, and a relay used to control the conduction or deactivation of the circuit containing the LED light as an example, when the relay is on, the current flowing through the LED light reaches the operating current of its LED (light-emitting diode), and the LED light illuminates; when the relay is off, the current flowing through the LED light does not reach the operating current of its LED, and the LED light turns off. In other examples, the load is a purely resistive device, such as an incandescent lamp.

[0037] The switch control circuit described in this application performs switch control logic processing and internal power supply processing using a rectified electrical signal provided by a rectifier circuit. To provide power to the power supply during both the off and on periods of the switch circuit, the rectifier circuit can be connected to at least the input side of the switch circuit, enabling it to output a rectified electrical signal during both periods. For example, the rectifier circuit is electrically connected to the input terminal of the switch circuit. Alternatively, the rectifier circuit can be electrically connected to both the input and output terminals of the switch circuit. Here, the power supply can be a terminal that outputs a power supply signal, and the switch control circuit is a circuit that provides a stable power supply output to this terminal. Through the power supply provided by the switch control circuit, the power supply provides the operating voltage to the circuit connected to it, enabling its operation.

[0038] To ensure power supply during both the open and closed periods of the switching circuit, the switch control circuit switches power supply based on the open and closed operations of the switching circuit to continuously output power. For this purpose, please refer to [link to relevant documentation]. Figure 1 The diagram shows a schematic circuit framework of the switch control circuit in one embodiment. The switch control circuit includes: a transformer circuit 11, a power management circuit 12, and a control circuit 13.

[0039] The transformer circuit 11 is connected to the rectifier circuit and is used to provide power to the power supply via the rectified electrical signal. The transformer circuit includes a primary-side input unit and a secondary-side output unit. The primary-side input unit and the secondary-side output unit each include a primary winding and a secondary winding based on the mutual inductance principle. The primary-side input unit is connected to the rectifier circuit, and the secondary-side output unit outputs the power supply. During the switching circuit's open state, the transformer circuit utilizes the mutual inductance principle of inductors to convert the rectified electrical signal into a power supply signal. The power-consuming devices include devices that operate according to a preset operating voltage, such as semiconductor devices like chips and power transistors, and relays.

[0040] Here, since the transformer circuit is used as a power supply when the switching circuit is off, and considering the certain degree of arbitrariness in the actual installation of the intelligent switch containing the switching control circuit, it is necessary to ensure that the transformer circuit has high power conversion efficiency. This arbitrariness manifests in the order in which the switching circuit and the load are connected to the live wire; for example, the switching circuit may be connected to the live wire before the load, or after the load.

[0041] In an assembly structure where the load is connected to the live wire, during the period when the switching circuit is open, a current lower than the load operating voltage is needed to form a power supply loop with the switching control circuit and ground to create a energized loop for the internal power supply circuit of the switching control circuit. To prevent excessive current in this energized loop from causing abnormal load operation, the primary input unit and secondary output unit of the transformer circuit need to maximize energy conversion. Therefore, in some examples, the secondary output unit includes a secondary winding and a unidirectional conduction module. The output terminal of the secondary winding is connected to the unidirectional conduction module, and the unidirectional conduction module and the secondary winding are connected to a common ground, thereby maximizing the output of converted electrical energy from the secondary winding and improving the conversion efficiency of the transformer circuit. Here, the unidirectional conduction module is used to prevent current backflow in the circuit containing the secondary winding. In some examples, the unidirectional conduction module includes a diode, and optionally also includes a capacitor. Please refer to [link to relevant documentation]. Figure 2 The diagram shows a circuit structure schematic of a switch control circuit in one embodiment. The unidirectional conduction module includes a diode D11 and a capacitor C11. The cathode of diode D11 is connected to one end of the secondary winding, and the anode is connected to one end of capacitor C11, forming the output terminal of the secondary output unit 112. The other end of capacitor C11 shares a common ground with the other end of the secondary winding. This allows the secondary winding to maximize the conversion of induced energy into electrical energy, which is then filtered by capacitor C11 and supplied to the power supply.

[0042] In order to control the transformer circuit to provide a stable power supply during the switching circuit being open, the power management circuit is at least connected to the primary-side input unit. The power management circuit is used to acquire a first sampling signal reflecting the power supply signal output by the power supply during the switching circuit being open, and to control the current flowing through the primary-side input unit based on the first sampling signal so that the power supply output by the secondary-side output unit is stable.

[0043] Here, the power management circuit can be formed by integrating discrete components on a PCB board, or by forming the power management circuit on a wafer using semiconductor processes and packaging it into a chip.

[0044] Here, to accurately reflect the fluctuations in the power supply signal, the power management circuit acquires the first sampling signal from the line where the secondary output unit is located. For example, the first sampling signal can come directly from the power supply signal output by the secondary output unit, directly reflecting the power supply signal. Alternatively, the first sampling signal comes from the power pin of an electrical device operating on power supplied by the power supply, such as the power pin of a CPU chip operating on power supplied by the power supply, which indirectly reflects the power supply signal provided by the secondary output unit using the standard power supply signal of the powered electrical device. Here, depending on the actual design of the sampling circuit for acquiring the first sampling signal, the first sampling signal can be a voltage signal or a current signal. For example, a current sampling device is used to acquire the current at the output terminal of the secondary output unit to obtain a current signal, i.e., the first sampling signal; the current flowing through the primary input unit is controlled based on the first sampling signal; or, when appropriate, a current-to-voltage device is used to convert the first sampling signal into a voltage signal, and the voltage signal is used to control the current flowing through the primary input unit. For example, a voltage sampling device is used to collect the voltage at the output terminal of the secondary output unit to obtain a voltage signal, namely the first sampling signal; the current flowing through the primary input unit is controlled based on the first sampling signal; or, when appropriate, a voltage-to-current device is used to convert the first sampling signal into a current signal, and the current signal is used to control the current flowing through the primary input unit.

[0045] In some examples, the switch control circuit further includes a first sampling circuit connected between the secondary output unit and the power management circuit. The first sampling circuit is used to sample the output side of the secondary output unit and obtain a first sampling signal. The first sampling circuit 14 includes voltage divider resistors R11 and R12 connected between the secondary output unit 112 and ground, and outputs the first sampling signal FB1 from the connection of resistors R11 and R12.

[0046] Here, the first sampling circuit can be configured independently and connected to a chip pin in the chip integrating the power management circuit. For example, the first sampling circuit can be externally mounted and connected to the first sampling pin of the chip containing the power management circuit and the output terminal of the secondary output unit, and the chip directly acquires the first sampled signal after voltage division. Alternatively, the first sampling circuit can be integrated with the power management circuit. For example, if the power management circuit and the first sampling circuit are integrated into a single chip, the first sampling pin of the chip is connected to the output terminal of the secondary output unit, and the first sampling circuit integrated inside the chip performs voltage division processing on the electrical signal acquired by the first sampling pin to obtain the first sampled signal after voltage division processing.

[0047] The power management circuit controls the current flowing through the primary input unit based on the first sampled signal. Here, during the off-state of the switching circuit, the power management circuit acts as a control circuit for the transformer circuit. It uses the voltage (or current) of the first sampled signal, which reflects the power supply, to control the current in the circuit containing the primary input unit of the transformer circuit. This changes the current flowing through the primary winding of the primary input unit, allowing the supply voltage of the secondary output power supply, converted via mutual inductance, to be maintained within a stable voltage range. For example, the power management circuit controls the change in current flowing through the primary winding by switching the circuit containing the primary input unit on and off based on the voltage of the first sampled signal.

[0048] In some implementations, to ensure AC power is available during the switching circuit's open state, the rectifier circuit includes a first rectifier unit connected to the AC line on the input side of the switching circuit and providing a first rectified electrical signal to the transformer circuit. The power management circuit includes a control unit electrically connected to the primary-side input unit for acquiring the first sampling signal during the switching circuit's open state and controlling the current flowing through the primary-side input unit based on the first sampling signal.

[0049] Here, the control unit acquires a first sampling signal using any of the aforementioned examples and adjusts the current in the primary winding based on the voltage (or current) of the first sampling signal. For example... Figure 2 As shown, the control unit includes an adjustment module 121 and a first control module 122. The adjustment module 121 is located on the line between the primary input unit 111 and ground, and is used to control the on / off state or current change of the line between the primary input unit 111 and ground. In one example, the adjustment module 121 includes a resistor and a controlled switch, which are connected in series between the primary winding and ground. Examples of the controlled switch include any one or a combination of a bipolar junction transistor (BJT), a junction field-effect transistor (JFET), a depletion-mode MOS power transistor, and a thyristor. In another example, the adjustment module 121 includes multiple selection lines and selectors connected between the primary input unit and ground, wherein each selection line has a resistor with a different resistance value, and the selector is controlled to switch to different selection lines, causing a corresponding change in the current flowing through the primary input unit. The selector includes, but is not limited to, switching devices. For example, the adjustment module includes two selection lines, one of which is a wire, and the other is equipped with a resistor and a switching device; by default, when the switching device is off, the primary-side input unit is grounded through the wire, and when the switching device is on, the primary-side input unit is grounded through the resistor.

[0050] Here, the first control module is connected to the adjustment module and is used to control the adjustment module based on the first sampling signal.

[0051] Specifically, the first control module is connected to the control terminal of the regulating module and controls the regulating module to switch on or off or regulate the current by detecting the first sampling signal. Therefore, the first control module includes a detection submodule and a control submodule. The detection submodule is used to output a detection signal by detecting the voltage of the first sampling signal; and the control submodule is used to control the regulating module based on the detection signal.

[0052] In some examples, the detection signal can be a logic signal reflecting a comparison between the voltage of the first sampled signal and a preset reference voltage. For this purpose, the detection submodule includes a comparison sub-circuit that compares the voltage of the first sampled signal with the preset reference voltage and outputs a detection signal based on the comparison result. The reference voltage can be a reference voltage range or a reference voltage value set based on the supply voltage of the power supply.

[0053] The comparator circuit utilizes analog devices of logic devices and auxiliary logic devices to represent the detection logic between the first sampled signal and the reference voltage, and outputs a corresponding detection signal. This detection signal is a logic signal that uses a level signal to represent the detection result. For example, when the voltage of the first sampled signal is higher than the reference voltage Vref, the detection signal outputs a high level; when the voltage of the first sampled signal is lower than the reference voltage Vref, the detection signal outputs a low level. In practice, according to the logical expression requirements of the logic signals between the comparator circuit and the control submodule, the comparator circuit includes logic devices such as comparators, inverters, flip-flops, AND gates, and NOT gates. Examples of comparators include hysteresis comparators or voltage comparators. Examples of flip-flops include D flip-flops.

[0054] It should be noted that the above method of using a single level signal as a detection signal is only an example. In fact, the detection signal can be multiple logic signals. The control submodule uses the control type expressed by multiple logic signals to select the corresponding control method to control the adjustment module.

[0055] In other examples, the detection signal is an analog or digital signal reflecting the voltage difference between the voltage of the first detection signal and a preset reference voltage. For this purpose, the detection submodule includes a numerator circuit for generating an error signal representing the voltage difference between the voltage of the first sampled signal and the preset reference voltage, and outputting a detection signal based on the error signal. Here, the numerator circuit includes at least an error amplifier, examples of which include, but are not limited to, an error amplifier composed of transconductance and a filter capacitor, or an error amplifier including a subtractor, integrator, counter, and digital-to-analog converter. The numerator circuit may also include an amplifier connected to the output of the error amplifier to amplify the error voltage signal for fine control by the control submodule.

[0056] In fact, depending on whether the received detection signal is a logic signal or an error signal, the control submodule provides a corresponding circuit structure to control at least one of the switching frequency, on-time, and off-time of the regulating module; or to control the frequency of change of the regulating current of the regulating module. In some examples where the detection signal is a logic signal, taking the adjustment of the regulating module's on / off state as an example, the control submodule adjusts the duty cycle of its internal PWM signal based on the detection result of the supply voltage being too high or too low, thereby adjusting the ratio of the on-time and off-time of the regulating module, and thus adjusting the supply voltage output by the transformer circuit. In other examples where the detection signal is a logic signal, taking the adjustment of the regulating module's on / off state as an example, the control submodule adjusts the switching frequency of the regulating module based on the detection result of the supply voltage being too high or too low, thereby adjusting the supply voltage output by the transformer circuit. For example, the control submodule includes an adjustable frequency divider, which is adjusted according to the received detection signal to change the frequency of the control signal, and the switching frequency of the regulating module is controlled based on the changed frequency of the control signal. In some further examples where the detection signal is a logic signal, taking the adjustment of the current change of the regulating module as an example, the control submodule adjusts the duty cycle of the internal PWM signal based on the detection result indicating that the supply voltage is too high or too low, as represented by the detection signal. The duration of the high and low levels of the PWM signal corresponds to the duration of one selected circuit and the other selected circuit selected by the regulating module, respectively. The current regulation scheme provided in any of the above examples achieves the goal of stabilizing the supply voltage output by the transformer circuit.

[0057] In some examples where the detection signal is an error signal, taking the adjustment of the switching on / off state of the regulating module as an example, the control submodule contains a timer. The timer uses the voltage of the detection signal as a reference voltage and times at least one of the durations of the on-state and off-state of the regulating module. Then, based on the timeout signal generated at the corresponding timeout moment, it controls the regulating module to switch between the on-state and off-state. The timer can be exemplified as a timing circuit including a capacitor and its charging / discharging circuit; or as a timing circuit including a clock generator, a counter, and a digital-to-analog converter. In further examples where the detection signal is an error signal, taking the adjustment of the current change of the regulating module as an example, the control submodule adjusts the duty cycle of the internal PWM signal according to the error voltage represented by the detection signal. The durations of the high and low levels of the PWM signal correspond to the durations of one selected circuit and the other selected circuit selected by the regulating module, respectively. The current adjustment scheme provided by any of the above examples achieves the goal of stabilizing the supply voltage output by the transformer circuit.

[0058] Based on the above examples and... Figure 2 For example, the operation of the transformer circuit and power management circuit in the switching control circuit is illustrated as follows: During the disconnection period of the switching circuit, the rectifier circuit outputs the first rectified electrical signal (corresponding to the rectified electrical signal in the figure) to the primary input unit 111 in the transformer circuit; utilizing the mutual inductance principle, the primary and secondary windings in the transformer circuit perform energy conversion, and the secondary output unit 112 in the transformer circuit provides a power supply signal (voltage Vout1) to the power supply. The detection submodule in the first control module 122 acquires the signal sampled by the first sampling circuit 14 to reflect the power supply signal. The first sampling signal FB1 is used as a detection signal. When the adjustment module 121 is turned on, the error voltage between the voltage of the first sampling signal FB1 and the preset reference voltage is used as a detection signal and output to the control submodule. The control submodule sets the conduction duration of the timer adjustment module 121 according to the voltage provided by the detection signal as the reference voltage for timing. When the timing exceeds the limit, the control submodule controls the adjustment module 121 to turn off and reset the timer. When the adjustment module 121 is turned off, the timer is set to count for a preset fixed duration. When the timing exceeds the limit, the control submodule controls the adjustment module 121 to turn on and reset the timer. This achieves the purpose of providing power to the internal switch control circuit using the transformer circuit during the switching circuit being turned off.

[0059] In other embodiments, the control unit further acquires a third sampling signal reflecting the line electrical signal in the line where the primary-side input unit is located, and controls the current flowing through the primary-side input unit based on the first and third sampling signals. The first sampling signal reflects the power output information currently provided by the secondary-side output unit, and the third sampling signal reflects the energy input information currently provided by the primary-side input unit. Controlling the current in the line where the primary-side input unit is located based on these two sampling signals improves the output stability of the power supply. The third sampling signal is acquired using a data acquisition device (group) connected to the primary-side input unit, and can be a voltage or current signal.

[0060] In some examples, the control unit controls the line containing the primary-side input unit to be turned on (or off) based on the first sampling signal, and controls the line containing the primary-side input unit to be turned off (or on) based on the third sampling signal. In still other examples, the control unit controls the line containing the primary-side input unit to be turned on based on the first sampling signal, and controls the line containing the primary-side input unit to be turned off based on both the first and third sampling signals.

[0061] For some specific examples, please refer to Figure 16 The diagram shows a circuit structure schematic of the control unit in another embodiment. The control unit includes an adjustment module 121 and a second control module 125. The switch control circuit also includes a third sampling circuit 16. The third sampling circuit 16 collects the voltage or current signal of the line where the primary-side input unit is located. For example, the third sampling circuit 16 includes a controlled switch and a sampling resistor. The input terminal of the controlled switch is connected to the input terminal of the adjustment module 121, the output terminal of the controlled switch is grounded through the sampling resistor, and the control terminal of the controlled switch is connected to the control terminal of the adjustment module 121 to synchronously receive the control of the second control module 125. The adjustment module 121 is similar to the aforementioned... Figure 2The circuit structure and execution process of the adjustment module 121 shown are the same or similar, and will not be described in detail here. The second control module 125 controls the adjustment module 121 to be turned on based on the first sampling signal FB1, and controls the adjustment module 121 to be turned off based on the first sampling signal FB1 and the third sampling signal CS. In some more specific examples, the second control module 125 controls the on-time of the adjustment module 121 based on the first sampling signal, and controls the off-time of the adjustment module 121 based on the first sampling signal FB1 and the third sampling signal CS. For example, the second control module 125 adjusts the response time for performing the corresponding turn-on or turn-off control operation by adjusting the frequency of the internal clock signal, so as to adjust the corresponding turn-on and turn-off times by changing the response time; and the second control module 125 determines the turn-on time by detecting the changes in electrical signals on both sides of the primary input unit and the secondary output unit, that is, by comparing the voltage between the third sampling signal CS and the COMP_CS signal obtained based on the first sampling signal, thereby adjusting the turn-off time; and the second control module 125 determines the turn-off time by monitoring the changes in electrical signals output by the secondary output unit, that is, by comparing the voltage of the first sampling signal FB1 with the preset reference voltage, thereby adjusting the turn-on time.

[0062] In other examples, the second control module includes an on control subcircuit, an off control subcircuit, and a control logic subcircuit.

[0063] The on-control subcircuit detects the acquired first sampling signal and obtains a corresponding detection signal, and outputs a clock signal based on the voltage of the obtained detection signal; wherein the frequency of the clock signal is related to the voltage of the obtained detection signal. The off-control subcircuit compares the third sampling signal with the detection signal output by the on-control subcircuit and outputs the logic signal corresponding to the comparison result. The control logic subcircuit controls the adjustment module to be on or off based on the clock signal and the logic signal corresponding to the comparison result. In other words, while maintaining the adjustment module on, the control logic subcircuit monitors the first logic signal indicating that the adjustment module should be off based on the clock signal. The off-control subcircuit compares the third sampling signal with the detection signal output by the on-control subcircuit and outputs the logic signal corresponding to the comparison result to the control logic subcircuit. Specifically, when the logic signal corresponding to the comparison result represents a first logic signal that causes the adjustment module to disconnect, the control logic sub-circuit controls the adjustment module to disconnect based on the first logic signal and the clock signal; when the logic signal corresponding to the comparison result does not represent the first logic signal, the control logic sub-circuit controls the adjustment module to turn on based on a preset second logic signal and the clock signal.

[0064] Please see Figure 17 The diagram shows a circuit structure schematic of the control unit in another embodiment, including a turn-on control subcircuit, a turn-off control subcircuit, and a control logic subcircuit. The turn-on control subcircuit performs low-pass filtering on the voltage of the acquired first sampled signal to obtain a detection signal COMP corresponding to the first sampled signal, and outputs a clock signal based on the voltage of the detection signal COMP; wherein the frequency of the clock signal is related to the voltage of the detection signal COMP. Using the clock signal as the clock reference for the control logic subcircuit to respond to received logic signals, the control logic subcircuit monitors a first logic signal indicating that the adjustment module should be turned off based on the clock signal while maintaining the adjustment module on. Simultaneously, the detection signal COMP is also directly output as COMP_CS to the turn-off control subcircuit, or processed according to a preset ratio and converted into COMP_CS before being output to the turn-off control subcircuit. The disconnection control subcircuit outputs the logic signal corresponding to the comparison result of the third sampling signal CS and COMP_CS to the control logic subcircuit; wherein, when the logic signal corresponding to the comparison result represents the first logic signal that causes the adjustment module to disconnect, the control logic subcircuit controls the adjustment module to disconnect based on the first logic signal and the clock signal; when the logic signal corresponding to the comparison result does not represent the first logic signal, the control logic subcircuit controls the adjustment module to turn on based on the preset second logic signal and the clock signal.

[0065] It should be noted that the on and off operations of the aforementioned adjustment module can also be replaced by switching operations between multiple lines. Each line has resistors of different resistance values ​​to change the current flowing through the primary-side input unit based on the first and second logic signals. Details will not be elaborated here.

[0066] Please see Figure 18 The diagram shows a circuit structure schematic of the control unit in another embodiment. The control unit includes a third protection module, an adjustment module, and a second control module. The adjustment module adjusts the current in the line containing the primary input unit by switching it on and off; this will not be described in detail here.

[0067] The second control module controls the adjustment module to be turned on and off accordingly. In some examples, Figure 18 The second control module 125 shown can be connected with Figure 17 The second control module 125' shown is similar, but the difference lies in that... Figure 18At least some of the electrical components in the second control module 125” shown switch between an inactive state and an active state based on the protection logic signal generated by the third protection module 124. The inactive state includes, but is not limited to: a state in which at least some electrical components are not responding to input signals under the enable control of the protection logic signal, or a state in which at least some electrical components are unable to operate under the power supply control of the protection logic signal. In some more specific examples, at least one of the conduction control sub-circuit, the disconnection control sub-circuit, and the control logic sub-circuit in the second control module 125” includes an enable terminal, through which the protection logic signal is received. The corresponding sub-circuit switches between an active state and an inactive state based on whether the protection logic signal is active or inactive, thereby controlling the adjustment module to be turned on and off when all sub-circuits are in an active state; and controlling the adjustment module 121 to be disconnected when at least one sub-circuit is in an inactive state. For example, the conduction control subcircuit includes an enable terminal and receives a protection logic signal. Controlled by the protection logic signal, when the conduction control submodule is in the working state, the conduction control subcircuit outputs a clock signal corresponding to the first sampled signal; when the conduction control submodule is in the non-working state, the conduction control subcircuit outputs no clock signal. As another example, the disconnection control subcircuit includes an enable terminal and receives a protection logic signal. Controlled by the protection logic signal, when the disconnection control subcircuit is in the working state, the disconnection control subcircuit outputs a corresponding logic signal based on the comparison result of the third sampled signal CS and COMP_CS; when the disconnection control submodule is in the non-working state, the disconnection control subcircuit maintains the output of a first logic signal indicating that the adjustment module is disconnected. For example, the control logic sub-circuit includes an enable terminal and receives a protection logic signal. Under the control of the protection logic signal, when the control logic sub-circuit is in the working state, the control logic sub-circuit controls the adjustment module to be disconnected or turned on based on the received first logic signal or second logic signal; when the control logic sub-circuit is in the non-working state, the control logic sub-circuit maintains the adjustment module disconnected.

[0068] The third protection module 124 is used to detect an electrical signal reflecting the power supply signal of the power supply, and to provide circuit protection for the power management circuit based on the detection result. The electrical signal reflecting the power supply signal can be the first sampling signal FB1, or the detection signal COMP provided by the conduction control sub-circuit. The third protection module 124 protects certain electrical components in the power management circuit by detecting the first sampling signal FB1 or the detection signal COMP, so that the line containing the primary-side input unit is disconnected during the protection period. Here, the third protection module 124 determines whether the power supply is overvoltage and / or overloaded by detecting the voltage or current of the first sampling signal FB1 or the detection signal COMP, and outputs a protection logic signal corresponding to the detection result. In some examples, during periods when the power supply is under light load, the third protection module 124 detects whether the first sampling signal is higher than a preset overvoltage protection threshold. If so, it outputs a valid first protection logic signal, causing the sub-circuit in the corresponding second control module 125” to enter a non-operating state based on the valid first protection logic signal. The third protection module 124 outputs an invalid first protection logic signal based on the detection result of the first sampling signal in real time and the preset overvoltage reset logic, thereby restoring the second control module 125” to the operating state. Examples of the overvoltage reset logic include at least one of the following: a reset logic set based on the detection result, and a reset logic set based on a preset timing duration. Examples of the reset logic set based on the detection result include continuous signal detection, and outputting an invalid first protection logic signal once the detection result changes. Examples of the reset logic set based on a preset timing duration include starting a timer when the protection logic signal is valid, and outputting an invalid first protection logic signal when the timer reaches a preset timing threshold. In some other examples, during periods of heavy load on the power supply, the third protection module 124 detects whether the first sampling signal is lower than a preset overload protection threshold. If so, it outputs a valid second protection logic signal, causing the sub-circuit in the corresponding second control module 125” to enter a non-operating state based on the valid second protection logic signal. The third protection module 124 outputs an invalid second protection logic signal based on the detection result of the first sampling signal in real time and the preset overload reset logic, thereby restoring the second control module 125” to the operating state. Examples of the overload reset logic include at least one of the following: a reset logic set based on the detection result, or a reset logic set based on a preset timing duration. Examples of the reset logic set based on the detection result include continuous signal detection, and outputting an invalid second protection logic signal once the detection result changes.Examples of reset logic based on a preset timing duration include starting the timing when the protection logic signal is valid, and outputting an invalid second protection logic signal when the timing reaches a preset timing threshold.

[0069] It should be noted that the protection threshold and detection logic set by the third protection module should be related to the signals obtained from the actual circuit structure, rather than being limited to the examples mentioned above. For instance, the third protection module detects the voltage of the detection signal COMP, and when the voltage of the detection signal COMP is detected to be lower than a preset overvoltage protection threshold, it determines to output the first protection logic signal, thereby enabling the chip containing the power management circuit to be in standby mode and / or effectively maintaining the chip's power supply capability. These will not be elaborated upon further here.

[0070] In other examples, the protection logic signal generated by the third protection module controls the regulating module to remain in an open state (not shown). For example, the third protection module is connected to the control terminal of a switch in the regulating module, and the corresponding switch remains open while the third protection module outputs a protection logic signal.

[0071] In some practical circuits, the power management circuit is presented as a chip. For details on chip integration, please refer to [link / reference needed]. Figure 3 The diagram shows a circuit structure schematic of a switch control circuit in one embodiment. The first self-powered circuit 15 can be externally connected between the secondary output unit 112 and the power supply pin VCC of the power management circuit 12. Alternatively, at least some components of the first self-powered circuit are integrated into the chip containing the power management circuit. For example, the diodes and / or voltage divider resistors in the first self-powered circuit are integrated into the power management circuit. Or, the entire first self-powered circuit is integrated into the chip containing the power management circuit.

[0072] To enable rapid power supply to the chip during the switching circuit's open state, some practical circuits include a startup power supply circuit in the switch control circuit. This startup power supply provides startup power to the power management circuit. The provided startup power supply includes providing a reference voltage and a chip startup voltage to the power management circuit. In some examples, the startup power supply circuit includes a capacitor and a charging unit for the capacitor. The charging unit uses the voltage variation of the rectified electrical signal provided by the rectifier circuit to generate a charging power supply to the capacitor until it is charged and reaches the startup voltage, thus enabling chip startup. During the switching circuit's open state, the control circuit and power management circuit in the switch control circuit rely on the power supply provided by the transformer circuit to perform corresponding control operations. For example, the control circuit uses the power provided by the power supply to continuously monitor whether control information is received in order to control the switching circuit to turn on. Alternatively, during the switching circuit's open state, the control circuit uses the power provided by the power supply to continuously monitor whether control information is received in order to output control signals to the pre-configured air conditioner according to the air conditioning and temperature indicated in the control information. The control circuit can also control smart curtains, etc., which will not be listed here.

[0073] Therefore, the control circuit includes an interaction unit and a processing unit. The interaction unit is used to acquire control information; the processing unit is connected to the interaction unit and is used to control at least the switching circuit to be turned on or off based on the control information.

[0074] In some examples, the interaction unit may include a human-computer interaction module for receiving user operations to obtain the control information. The human-computer interaction module may include, for example, an interaction panel with a touch medium, including but not limited to: a touchscreen, a button, a photosensitive device, etc. In other examples, the interaction unit may include a communication module for receiving and transmitting wireless signals containing control information. The communication module may include at least one of the following: short-range communication modules such as RF communication modules, WiFi communication modules, infrared communication modules, and Bluetooth communication modules; wide area network communication modules capable of accessing fiber optics, broadband, etc.; and communication modules that utilize a SIM card to access mobile networks, etc. The above examples may be combined or configured individually in the interaction unit. For example, the interaction unit includes a button for controlling a switching circuit and a wireless communication module for acquiring wireless signals. The interaction unit determines that it has received control information for turning on the switching circuit by monitoring the pulse signal generated by the button, and the interaction unit acquires the carried control information by demodulating and decoding the wireless signal. Here, the control information acquired using the wireless communication module may include control information for turning on the switching circuit, control information for controlling the switching circuits on other lines, and control information for controlling smart appliances to adjust, switch on, etc. The interaction unit provides the obtained control information to the processing unit, which converts the control information into control signals recognizable by the corresponding electrical device or switching circuit and outputs them.

[0075] Here, the processing unit includes processing modules capable of handling numerical operations, logical operations, and data processing, such as MCUs, CPUs, and programmable logic devices. Depending on the pin functions of the chip that packages the corresponding processing module, the processing unit can be electrically connected to a switching circuit or communicate via an interaction unit. Powered by the transformer circuit, the processing unit analyzes the received control information while the switching circuit is open to determine the controlled object and the timing of control execution. The processing unit may also include hardware modules such as timers, clock signal generators, and buffers to assist the processing module in performing corresponding control operations.

[0076] Here, the examples described above illustrate the internal power supply of the switch control circuit during the switch circuit's open state and the control circuit structure and operation process for controlling at least the switch circuit. During the switch circuit's on state, the switch control circuit can still provide internal power supply and control the open state of at least the switch circuit.

[0077] In order for the AC power output from the switching circuit to enter the rectifier circuit, in some embodiments, the switching control circuit connects two lines to the output terminal of the switching circuit. One line is connected to the rectifier circuit, so that the power management circuit can obtain the rectified signal and continuously supply power to the power supply through the rectified signal; the other line is connected to the neutral line of the AC power to enable the load to work normally.

[0078] In other embodiments, the switch control circuit controls the output terminal of the switch circuit to switch between a first line and a second line, so that the load and the switch circuit form corresponding energized circuits via the first line and the second line respectively in a time-sharing manner. The rectifier circuit is located on the second line and acquires an AC signal and outputs a corresponding rectified signal during the period when the second line is in an energized circuit. To distinguish it from the rectified signal received during the period when the switch circuit is off, the rectified signal received during the period when the switch circuit is on is referred to as the second rectified signal.

[0079] Please see here. Figure 4 The diagram shows a frame structure of the switch control circuit in another embodiment. The switch control circuit further includes a selection circuit 21, disposed on the AC line on one side of the output terminal of the switch circuit 31, for selecting whether to connect the switch circuit 31 to a first line or a second line during the conduction period, so as to form a power supply loop for the switch circuit 31 and the load. Correspondingly, the power management circuit 23 also includes a power supply unit, which converts the acquired second rectified electrical signal into a power supply signal (Vout1) when the selection circuit 21 switches to the second line, to connect the power supply. Specifically, when the AC voltage flowing through the switch circuit reaches the conduction voltage of the rectifier bridge in the rectifier circuit, the circuit loop containing the second line is activated. When the selection circuit 21 selects to connect the switching circuit 31 to the second line, the load (not shown), the switching circuit 31, the rectifier circuit 32, the power management circuit 23, and the voltage ground form a power-on loop. In other words, the AC signal flows to the voltage ground via the load 32, the switching circuit 31, the rectifier circuit 32, and the power management circuit 23. When the selection circuit 21 selects to connect the switching circuit 31 to the first line, the load, the switching circuit 31, and the urban power grid form another power-on loop. In other words, the AC signal flows to the voltage ground in the urban power grid via the load, the switching circuit 31, and the selection circuit 21.

[0080] In some examples, the selection circuit connects the switching circuit to the second line within a preset AC reference voltage range, and connects the switching circuit to the first line outside the reference voltage range. The reference voltage range can be determined based on the actual circuit design. For example, to ensure normal load operation, the reference voltage range is selected as a voltage range outside the load's operating voltage range, including but not limited to: zero-crossing voltage range, peak voltage range, or other voltage ranges. Taking an LED lamp as an example, the reference voltage range is selected as the zero-crossing voltage range. In still other examples, the selection circuit connects the switching circuit to the second line within the power supply's reference voltage range, and connects the switching circuit to the first line outside the reference voltage range.

[0081] In some examples, the selection circuit includes a switching unit M1, wherein the switching unit M1 is disposed on the AC power line where the switching circuit is located.

[0082] The switching unit is configured to be controlled to turn on or off based on a received shunt control signal, responding at least immediately to a switching operation that switches the switching circuit from access to the second line to access to the first line. Specifically, the switching unit may be controlled to turn off based on the received shunt control signal to allow the switching circuit to immediately or delayedly access the second line, or controlled to turn on based on the shunt control signal to allow the switching circuit to immediately access the first line. In some examples, the selection circuit further includes an on / off control device that generates a shunt control signal by detecting the phase of the alternating current and outputs it to the switching unit. In other examples, the shunt control signal is output to the switching unit from a power supply unit. The switching unit M1 includes a power transistor, wherein the control terminal of the power transistor is used to receive a shunt control signal, which is a voltage signal. When the shunt control signal indicates that the switching unit is turned on, the power transistor is turned on, so that the load and the switching circuit are connected to the neutral wire via the first line, and the load and the switching circuit are connected between the live wire and the neutral wire of the AC power supply. When the shunt control signal indicates that the switching unit is turned off, the power transistor is turned off, so that the load and the switching circuit are connected to the voltage ground in the power management circuit via the second line, and the load and the switching circuit are connected between the live wire and the voltage ground.

[0083] To maximize the efficiency of AC power utilization, the structure of the selection circuit is related to the rectifier circuit and load in this application. Taking a full-wave rectifier circuit as an example, when the phase of the AC power falls within a preset phase range, the selection circuit immediately selects the second line based on a time-division control signal; conversely, when the phase of the AC power exceeds the phase range, the selection circuit immediately selects the first line based on the time-division control signal. Again, taking a full-wave rectifier circuit as an example, when the voltage of the power supply falls within a preset reference voltage range, the selection circuit immediately selects the second line based on a time-division control signal; otherwise, the selection circuit immediately selects the first line based on the time-division control signal.

[0084] Please refer to the actual circuit structure of the rectifier circuit and the power supply unit. Figure 5 The diagram shows a circuit structure schematic of the switch control circuit in another embodiment, wherein the selection circuit further includes a phase limiting unit. For example, the rectifier circuit is a half-wave rectifier circuit, and the phase limiting unit forces the AC signal to flow through the first line during the negative half-cycle of the power frequency cycle.

[0085] Here, the phase limiting unit may be constituted by a separate electrical device or provided by a parasitic diode in the semiconductor device of the switching unit M1. In some examples, the phase limiting unit is a separate electrical device connected in parallel with the switching unit, used to, when the switching unit is open, delay or immediately perform a switching operation to switch the switching circuit from access to the first line to access to the second line, depending on the phase of the current alternating current. See also Figure 5 The phase limiting unit includes a diode D1 connected in parallel with the switching unit M1, with its cathode connected to the live wire and its anode connected to the neutral wire. When the switching unit M1 is turned on, the switching circuit and the load are connected between the live and neutral wires of the AC power supply, and the diode D1 is short-circuited. In other words, the selection circuit 21 connects to the first line. When the switching unit M1 is turned on and the diode D1 is turned off, the selection circuit switches from the first line to the second line. As the phase of the AC power supply changes, the voltage difference across the rectifier circuit of the second line is greater than its forward voltage, and the second line is turned on.

[0086] As shown in the above example, if the phase of the AC current falls within the negative half-cycle (-180-0 degrees) of the power frequency cycle when the switching unit is turned off, the selection circuit delays switching to the second line until the AC current phase enters the positive half-cycle (0-180 degrees) of the power frequency cycle. Furthermore, the second line conducts when the AC current voltage reaches the turn-on voltage of the rectifier bridge in the rectifier circuit. Conversely, if the phase of the AC current falls within the positive half-cycle (0-180 degrees) of the power frequency cycle when the switching unit is turned off, the selection circuit immediately switches to the second line. And the second line conducts when the AC current voltage reaches the turn-on voltage of the rectifier bridge in the rectifier circuit.

[0087] It should be noted that, depending on the selection of components such as the rectifier circuit, selection circuit, and power management circuit, such as the selection of the operating voltage of semiconductor devices like diodes and power transistors, when the selection circuit switches between the first and second lines, it may be limited by the operating voltage of the corresponding semiconductor device, potentially causing the corresponding line to be momentarily unconducted. For example, the voltage of AC signals corresponding to phases of 0, -180, and 180 degrees, and those near these phases, may not reach the operating voltage of the diode. In such cases, the selection circuit should be considered to have selected either the first or second line, only momentarily in a non-conducting state. However, this does not affect the technical concept mentioned in this application of achieving stable power output from the power management circuit through time-sharing AC power sharing. Similarly, when the selection circuit switches between the first and second lines, it may be affected by the operating voltage of the corresponding semiconductor device, parasitic capacitance charging and discharging, etc., potentially causing the actual switching operation of the first and second lines in the circuit to differ from the momentary situation in the example above. For example, both the first and second lines may be conducting or both may be disconnected. This should not affect the technical concept mentioned in this application of achieving stable power output from the power management circuit through time-sharing AC power sharing. This will not be repeated hereafter.

[0088] When the second line is conducting, the rectifier circuit outputs a second rectified electrical signal. The connecting power supply unit is connected at least between the rectifier circuit and the output terminal of the power supply. It performs low-pass filtering, voltage regulation, and other processing on the received second rectified electrical signal and outputs it to the output terminal to continuously provide the power supply voltage. For this purpose, the connecting power supply unit at least includes an output module for continuously providing power based on the received second rectified electrical signal. In some examples, depending on the voltage range of the rectified electrical signal output by the rectifier circuit, the output module can directly output the second rectified electrical signal to the output terminal of the power supply. For example, the output module is a wire. In other examples, the output module includes at least one of a filter capacitor and a voltage divider resistor to match the voltage of the provided power supply signal with the required power supply voltage. In still other examples, the connecting power supply unit further includes a second protection module 231 for providing overcurrent protection to the power supply. For example, the second protection module includes a protection resistor disposed between the rectifier circuit and the output terminal of the power supply, and a comparator OCP for detecting the voltage difference across the protection resistor. Specifically, when the comparator OCP detects that the voltage difference across the protection resistor exceeds a preset protection voltage threshold, it determines that an anomaly has occurred and outputs an overcurrent protection detection signal to allow the control circuit to perform forced control operations on the switching circuit. The second protection module may also be composed of other circuits including transistors and / or triodes, which will not be listed here.

[0089] It should be noted that the examples of the above output modules are not mutually exclusive and can be used in combination according to the actual circuit design. Moreover, for the purpose of circuit optimization, the electrical components mentioned in the foregoing examples can also serve the corresponding functions of other circuit units in the rectifier circuit and the switch control circuit. For example, the filter capacitor can be shared with the capacitor in the rectifier circuit. Here, those skilled in the art should understand the electrical components described in the examples of this application from the perspective of the role of the circuit components in the circuit structure.

[0090] The power supply unit further includes a branch control module connected to the selection circuit. This module detects an AC signal or a power supply signal during the conduction of the switching circuit and outputs a branch control signal to the selection circuit. This controls the selection circuit to switch between the first and second lines, allowing the switching circuit to connect to either the first or second line. Depending on the sampling location of the second sampling circuit, in some examples, the second sampling signal represents a power supply signal, and the branch control module can detect the voltage of the power supply signal by detecting the voltage of the second sampling signal. In other examples, the second sampling signal represents an AC signal, and the branch control module can detect the voltage of the AC signal by detecting the voltage of the second sampling signal.

[0091] To facilitate voltage detection by the branch control module, the switch control circuit further includes a second sampling circuit. This circuit generates a second sampling signal from the electrical signal reflecting the AC phase signal in the second line or from the power supply signal of the power supply, and outputs it to the branch control module. In some examples, the second sampling circuit directly samples the AC signal to obtain the second sampling signal. In other examples, the second sampling circuit includes first voltage divider resistors R21 and R22 disposed between the second rectified electrical signal output terminal of the rectifier circuit and ground; wherein R22 is grounded. The second sampling circuit may also include second voltage divider resistors R23 and R24 connected in parallel with voltage divider resistor R22. In still other examples, the second sampling circuit acquires the power supply signal from the power supply side and provides the obtained second sampling signal to the power management circuit. For example, it may originate from the power supply pins of a CPU chip operating by the power supply, which indirectly reflects the power supply signal provided by the power supply using the standard power supply signal of the powered electrical device. Here, depending on the actual design of the sampling circuit for acquiring the second sampling signal, the second sampling signal can be a voltage signal or a current signal. For example, a current sampling device can be used to acquire the current output by the power management circuit to obtain a current signal, i.e., a second sampling signal; the current or voltage output by the power management circuit can be controlled based on the second sampling signal; or, when appropriate, a current-to-voltage converter can be used to convert the second sampling signal into a voltage signal, and the voltage signal can be used to control the current or voltage output by the power management circuit. As another example, a voltage sampling device can be used to acquire the voltage output by the power management circuit to obtain a voltage signal, i.e., a second sampling signal; the current or voltage output by the power management circuit can be controlled based on the second sampling signal; or, when appropriate, a voltage-to-current converter can be used to convert the second sampling signal into a current signal, and the current signal can be used to control the current or voltage output by the power management circuit.

[0092] Please see Figure 6 The diagram illustrates the circuit structure of the switch control circuit in one embodiment, wherein the second sampling circuit can be fully or partially integrated into the chip containing the power management circuit. For example, the first voltage divider resistors R21 and R22 in the second sampling circuit are externally connected between the rectifier circuit and the chip via the chip pin FB2, providing a first voltage divider signal of the second rectified electrical signal to the chip pin FB2. The second voltage divider resistors R23 and R24 in the second sampling circuit are integrated into the chip, and further divide the first voltage divider signal via pin FB2 to obtain a second sampling signal, which is then provided to the branch control module inside the chip. The branch control module detects the second sampling signal and outputs a branch control signal to the selection circuit to control the selection circuit to switch between the first line and the second line.

[0093] For example, the selection circuit 21 is connected to the second line by default, and the rectifier circuit outputs a full-wave rectified electrical signal. When the branch control module 233 detects that the voltage of the second sampled signal exceeds the reference voltage range, it outputs a branch control signal to control the selection circuit to switch from the second line to the first line; and starts a timer. When the timer reaches a timer threshold, the branch control module 233 adjusts the branch control signal to control the selection circuit 21 to switch from the first line to the second line. The timer threshold is related to the duration the output module 232 maintains the supply voltage, the AC power frequency cycle, etc. For example, if the output module 232 maintains a supply voltage of t milliseconds to the power supply based on the received second sampled signal within the reference voltage range, then the timer threshold can be less than or equal to t milliseconds. Alternatively, the timer threshold can be less than half a power frequency cycle to accommodate the zero-crossing detection requirements of the zero-crossing detection circuit mentioned later.

[0094] Combination Figure 5 The selection circuit shown is configured such that selection circuit 21 is connected to the second line by default, and the rectifier circuit outputs a half-wave rectified signal. When the shunt control module 233 detects that the voltage of the second sampled signal exceeds the reference voltage range, it outputs a shunt control signal to control the switching unit M1 to conduct, i.e., the selection circuit switches from the second line to the first line. After a delay, the shunt control module 233 adjusts the shunt control signal to disconnect the switching unit M1. If the AC current is in the negative half-cycle (-180-0 degrees) at the moment the switching unit M1 is disconnected, then from the moment of disconnection to the negative half-cycle... During the time interval at the end of the period, the switching circuit maintains connection to the first line using the phase limiting unit. During this period, the voltage of the second rectified electrical signal detected by the shunt control module 233 does not exceed the reference voltage range until the AC phase enters the positive half-cycle (0-180 degrees), at which point the selection circuit switches to the second line. When the voltage difference across the rectifier bridge in the rectifier circuit is greater than its conduction voltage, the second line is turned on. At this time, the voltage of the second sampled signal begins to change, and when the voltage exceeds the reference voltage range, the shunt control module 233 controls the switching unit M1 to turn on again.

[0095] like Figure 6As shown, the branch control module includes a comparison sub-circuit and a control sub-circuit. The comparison sub-circuit compares the voltage of the second sampled signal with the reference voltage range and generates a corresponding comparison result. The voltage range may include upper and lower voltage thresholds, or only the upper voltage threshold (or lower voltage threshold). Taking a zero-crossing voltage range as an example, the lower voltage threshold is zero voltage or a voltage value close to zero, and the upper voltage threshold is a reference voltage Vref3. When the comparison sub-circuit detects that the voltage of the second sampled signal is higher than Vref3, the output detection signal (e.g., a high level) indicates that the voltage of the second rectified signal exceeds the zero-crossing voltage range; when the comparison sub-circuit detects that the voltage of the second sampled signal is lower than or equal to Vref3, the output detection signal (e.g., a low level) indicates that the voltage of the second sampled signal is within the zero-crossing voltage range.

[0096] The control subcircuit is connected to the comparison subcircuit and is used to output the shunt control signal based on the comparison result to control the selection circuit to switch from the second line to the first line, i.e., the switching circuit is connected to either the first line or the second line. The control subcircuit includes logic devices (groups) that output the shunt control signal based on control logic set according to the received detection signal. The logic devices (groups) include, but are not limited to, logic gates, flip-flops, etc. For example, when the control subcircuit receives a high-level signal, it outputs a shunt control signal to switch the selection circuit from the second line to the first line according to preset control logic. Figure 6 As shown, taking the switching unit M1 in the selection circuit as an example containing an N-type power transistor, when the branch control signal output by the control sub-circuit through the pin GATE is a high-level signal, it indicates that the N-type power transistor is turned off, and the selection circuit switches from the second line to the first line.

[0097] The control subcircuit also includes a timer, which is controlled by a detection signal output by the comparator subcircuit. When the detection signal indicates that the voltage of the second rectified electrical signal exceeds a reference voltage range, the timer is started, and when the elapsed duration reaches a timing threshold, a timeout detection signal is output. The logic devices (groups) in the control subcircuit, based on the control logic of the detection signal and the timeout detection signal output by the comparator subcircuit, adjust the branch control signal to switch the selection circuit from the first line to the second line. (Combined with...) Figure 6The example shown, along with the switching unit M1, includes an N-type power transistor. When the shunt control signal transitions from high to low, the N-type power transistor turns on, and the selection circuit switches from the first line to the second line during the positive half-cycle of the AC current. Similar to the aforementioned timing threshold, the timing threshold can be a fixed time threshold or a threshold set based on the duration for which the selection circuit selects the first line within at least one switching cycle. Here, the switching cycle refers to the duration for the selection circuit to complete one switch from the first line to the second line and then back to the first line.

[0098] by Figure 6 For example and in combination Figure 7 The circuit waveform diagram shown illustrates the operation of the switch control circuit as follows: The selection circuit 21 defaults to connecting the switch circuit 31 to the second line to provide an AC signal to the rectifier circuit 32. The rectifier circuit 32 outputs a second rectified signal, and the second sampling circuit 25 samples the second rectified signal and outputs a second sampled signal. The comparator sub-circuit in the shunt control module 233 compares whether the voltage of the second sampled signal falls within a preset zero-crossing voltage range. If so, it outputs a level signal to the control sub-circuit. The control sub-circuit outputs a corresponding shunt control signal to maintain the selection circuit connected to the second line. During this period, the output module 232 converts the voltage of the second rectified signal into a supply voltage until the voltage of the second rectified signal reaches the specified level. The comparator circuit compares the voltage of the second sampled signal to see if it exceeds the zero-crossing voltage range. When the voltage of the second sampled signal exceeds the zero-crossing voltage range, the comparator circuit outputs another level to the control circuit. The control circuit adjusts the voltage of the branch control signal (the voltage output by the Gate pin) to control the selection circuit 21 to switch from the second line to the first line, at which point the second rectified signal is phase-cut. On the other hand, it starts a delay timer and adjusts the voltage of the branch control signal to a high level when the delay timer expires, so that the rectifier circuit outputs the second rectified signal to the output module. At the same time, the second sampling circuit 21 continues to output the second sampled signal to the comparator circuit, and so on, repeating the above process.

[0099] In another example, to improve the accuracy of the timer, the control sub-circuit further includes a timer controller for monitoring and storing the time t' required from the turn-on of switch unit M1 to the switching of the selection circuit to the second line, and adjusting the delay timing based on at least one monitored time t'. The timer controller includes at least: a latch and logic devices (groups), a timer resetter, etc. The logic devices (groups) include, but are not limited to, at least one or a combination of: comparators, gate devices, amplifiers, adders, subtractors, etc. For example, the branch control signal that turns on switch unit M1 is used as a trigger signal to start the timer. When the rectifier circuit is detected to be on, the timer stops and the current time t' is stored in the latch as the timing reference threshold for the next cycle. Another example is detecting the timing duration of the timer over multiple cycles (i.e., the time interval between the turn-on of switch unit M1 and the turn-on of the rectifier circuit), and calculating the timing reference threshold for the subsequent cycle based on the timing duration of multiple cycles.

[0100] In other examples, to prevent excessive voltage in the rectified signal received by the power supply unit when the selection circuit switches to the second line, which could easily damage the components in the power management circuit, the power supply unit further includes a first protection module. This module detects the voltage of the electrical signal reflecting the AC signal flowing through the second line, and controls the selection circuit to switch from the second line to the first line when the detected voltage exceeds a preset protection voltage threshold. The electrical signal reflecting the AC signal flowing through the second line can be either a second sampling signal or a second detection signal.

[0101] Please see Figure 19 The diagram shows a structural schematic of the power supply unit in another embodiment. The first protection module 234 is connected in parallel with the branch control module 233 and detects the voltage of the second sampled signal. Here, the first protection module 234 can directly compare the voltage of the second sampled signal with a preset protection voltage threshold, or it can perform voltage division or amplification of the second sampled signal before comparing it with the protection voltage threshold. When the voltage of the second sampled signal is higher than the preset protection voltage threshold, the selection circuit is controlled to switch from the second line to the first line. The protection voltage threshold is higher than or equal to the upper voltage limit of the aforementioned reference voltage range.

[0102] For example, the first protection module includes a comparator A5 and a controlled switch M5. The controlled switch M5 is connected between the control terminal of the selection circuit and a preset voltage. One input of the comparator A5 receives a second sampling signal, and the other input receives a protection voltage threshold. The output of the comparator A5 is connected to the control terminal of the controlled switch M5. When the comparator A5 detects that the voltage of the second sampling signal is higher than the protection voltage threshold, it controls the controlled switch M5 to conduct. The voltage at the control terminal of the selection circuit is forced to be set to the preset voltage. Thus, the selection circuit is forced to switch to the first line, i.e., the switching circuit and the load form a power-on loop with the neutral line. Simultaneously, or with a slight delay, the shunt control module also outputs a shunt control signal to switch the selection circuit to the first line and maintains the shunt control signal for the delay period. When the comparator A5 detects that the voltage of the second sampling signal is not higher than the protection voltage threshold, it controls the controlled switch M5 to open. The voltage at the control terminal of the selection circuit is determined by the voltage output by the shunt control module. Thus, the selection circuit switches between the first line and the second line according to the control of the shunt control module.

[0103] To mitigate the instantaneous current interruption or reverse current flow caused by the power supply switching during the transition from off to on of the switching circuit, diodes are provided at the output terminals of both the secondary output unit and the continuous power supply unit. One diode is connected between the output terminal of the secondary output unit and the output terminal of the power supply; the other diode is connected between the output terminal of the continuous power supply unit and the output terminal of the power supply. An energy storage circuit is also provided at the output terminal of the power supply to discharge during the switching process, thereby achieving uninterrupted power supply. Since the power management circuit uses active components or components requiring continuous power for signal processing during the off-state of the switching circuit, the power management circuit itself is also powered by the power supply of the transformer circuit. The switch control circuit also includes a second self-powered circuit for supplying power to the power management circuit during the on-state of the switching circuit. In some examples, this circuit is connected between the output terminal of the power supply and the power supply terminal of the power management circuit. For example, the second self-powered circuit can be a wire connected between the power supply and the power supply terminal of the power management circuit. For example, depending on the actual operating voltage of the power management circuit, the second self-powered circuit may also include at least one of the following connected between the output terminal of the power supply and the power supply terminal of the power management circuit: a voltage divider resistor, a low-dropout linear regulator, etc. In other examples, the input terminal of the second self-powered circuit is connected to an AC line through a second line, or the input terminal of the second self-powered circuit is connected to the output terminal of a rectifier circuit, or the input terminal of the second self-powered circuit is connected to the output terminal of the power supply, and the output terminal of the second self-powered circuit is electrically connected to the power supply terminal of the power management circuit. During the conduction period of the switching circuit, the second self-powered circuit draws power from the conductive loop where the switching circuit is located and provides it to the power management circuit after conversion; during the discontinuation period of the switching circuit, the first self-powered circuit draws power from the output terminal of the power supply and provides it to the power management circuit after conversion.

[0104] In some practical circuits, the power management circuit is presented as a chip. Depending on the chip integration, the second self-powered circuit can be externally connected between the power supply and the power pin VIN2 of the power management circuit. Alternatively, at least some components of the second self-powered circuit can be integrated into the chip containing the power management circuit.

[0105] During the conduction period of the switch circuit, the power management circuit in the switch control circuit provides continuous power, and the control circuit in the switch control circuit can perform control operations similar to those during the disconnection period. For example, it can perform control operations such as adjusting the air conditioner temperature, timing the start / stop of electronic devices, and disconnecting the switch circuit. Further details are omitted here.

[0106] In some practical applications, when a load is powered on or off within the peak AC voltage range, the semiconductor devices and switching circuits in the load are easily damaged by the instantaneous high voltage, causing load damage. Therefore, the switching control circuit mentioned in this application also integrates a zero-crossing detection circuit to detect the phase of the current AC signal based on the zero-crossing phase interval and output a zero-crossing detection signal to the control circuit. The control circuit then controls the switching circuit to turn on or off based on the zero-crossing detection signal and upon receiving control information. The control information can be obtained based on control logic processing of at least one logic signal. The sources of the logic signal include, but are not limited to: on / off commands issued by wireless devices such as remote controls and smart terminals; mechanical on / off operations; electrical signals emitted by touch panels; detection of the zero-crossing detection signal; or other devices including timers. The control circuit outputs the control signal based on preset control logic for at least one of the above logic signals.

[0107] In some examples, the control circuit can be triggered by a zero-crossing detection signal generated after receiving control information to control the switching circuit to turn on or off. In another example, the control circuit presets a response delay duration for the switching circuit. The control circuit predicts the time to turn the switching circuit on or off within the time interval of subsequent zero-crossing detection signals based on the time intervals of multiple zero-crossing detection signals, and sets a corresponding timer. If control information is received during this timer, the corresponding control operation is performed when the timer expires, i.e., the switching circuit is turned on or off; if control information is received during this timer, the timer is reset when the timer expires and the start time of the timer is redefined. For example, the time intervals of multiple consecutively received zero-crossing detection signals are recorded, and abnormal time intervals, such as those that are too long or too short, are eliminated. The average time interval of the zero-crossing detection signals is calculated. Based on this average time interval and the response delay of the switching circuit, the timing for controlling the switching circuit to turn on or off when the subsequent AC phase approaches zero phase is predicted, and a corresponding timer is started. When control information for controlling the switching circuit is received during this timer, the corresponding control operation is executed when the timer expires. Otherwise, the timer is reset, the timing for the next time the control operation can be executed is calculated, and the corresponding timer is started again.

[0108] Here, the zero-crossing detection circuit can be connected to the rectifier circuit to detect the zero-crossing phase of the current AC power supply by detecting the zero-crossing phase of the acquired rectified signal. The zero-crossing detection circuit can directly detect whether the voltage of the received rectified signal conforms to the zero-crossing voltage range corresponding to the zero-crossing phase range, or it can sample the rectified signal and then perform the voltage detection. When the detected voltage falls within the zero-crossing voltage range, a zero-crossing detection signal is output. The zero-crossing detection circuit can be configured separately from the chip containing the power management circuit, or at least partially integrated into the chip.

[0109] In some embodiments, the zero-crossing detection circuit performs zero-crossing detection of the AC current during the switching circuit's open state to prevent the load from being connected to the peak voltage range of the AC current at the instant the switching circuit is turned on. To this end, the zero-crossing detection circuit includes a first zero-crossing detection unit. This first zero-crossing detection unit is used to detect whether a first detection signal reflecting the current AC current phase falls within the zero-crossing phase range during the switching circuit's open state, and outputs a zero-crossing detection signal.

[0110] In some examples, the first zero-crossing detection unit obtains a first detection signal by acquiring the rectified AC signal, detects whether the first detection signal falls within the zero-crossing phase interval, and outputs the zero-crossing detection signal. Specifically, the first detection signal can be sampled from the first rectified AC signal. For example, the first zero-crossing detection unit includes a sampling resistor connected to the rectifier circuit, and obtains a first detection signal that can describe the voltage change of the first rectified AC signal in real time by voltage division processing of the sampling resistor.

[0111] In other examples, in order for the first zero-crossing detection unit to acquire a rectified electrical signal with a more significant waveform, the first zero-crossing detection unit directly acquires the AC signal on the AC line during the period when the switching circuit is off, and obtains a first detection signal that can reflect the first rectified electrical signal, and then outputs the corresponding zero-crossing detection signal by detecting the voltage of the first detection signal.

[0112] Here, the zero-crossing detection signal is generated based on the comparator in the first zero-crossing detection unit. One input of the comparator receives the first detection signal, and the other input receives the upper limit of the zero-crossing voltage range. When the voltage of the first detection signal is lower than the upper limit, the zero-crossing detection signal is output. The zero-crossing detection signal is a logic signal, using high and low levels to represent the comparison result of the comparator. For example, when the voltage of the first detection signal is lower than or equal to the upper limit, the comparator outputs a high level, indicating that the phase of the current rectified signal is near zero. When the voltage of the first detection signal is higher than the upper limit, the comparator outputs a low level, indicating that the phase of the current rectified signal is not near zero. Subsequent logic units can provide corresponding detection logic and output the zero-crossing detection signal based on the logic expressed by the high and low levels of the zero-crossing detection signal.

[0113] To reduce the internal losses of the zero-crossing detection circuit, the first zero-crossing detection unit provided in this application can periodically detect the phase of the first detection signal and output a zero-crossing detection signal corresponding to the zero-crossing phase interval. Here, the first zero-crossing detection unit can sample the first rectified electrical signal or AC signal using a sampling interval shorter than the change period of the rectified electrical signal to obtain the first detection signal, and output the corresponding zero-crossing detection signal by detecting the voltage of the periodically sampled first detection signal. Alternatively, the first zero-crossing detection unit can use a detection interval shorter than the change period of the rectified electrical signal to periodically detect the voltage of the real-time sampled first detection signal and output the corresponding zero-crossing detection signal. The purpose of using a sampling interval or detection interval shorter than the change period of the rectified electrical signal is to ensure that the first zero-crossing detection unit can acquire the first detection signal corresponding to the first rectified electrical signal or AC signal within the zero-crossing voltage interval. For example, the sampling interval or detection interval can be set using the power frequency period of the AC signal.

[0114] On the other hand, depending on the electrical components in the detection circuit actually integrated into the chip, the chip may include at least one chip pin for outputting a zero-crossing detection signal. For example, the chip may include two chip pins for outputting a zero-crossing detection signal, one outputting the zero-crossing detection signal when the switching circuit is off, and the other outputting the zero-crossing detection signal when the switching circuit is on. Alternatively, the chip may include a chip pin that can output a zero-crossing detection signal during both the on and off periods of the switching circuit. The output zero-crossing detection signal may be provided by a zero-crossing detection module, logic unit, or zero-crossing detection signal output module in the detection circuit, which will not be detailed here.

[0115] For this purpose, please refer to Figure 8 The diagram shows the circuit structure of the first zero-crossing detection unit. The first zero-crossing detection unit 41 includes a first detection signal generation module and a first zero-crossing detection module 413.

[0116] The first detection signal generation module generates a first detection signal corresponding to the current AC phase at intervals; wherein the first detection signal reflects at least the AC signal within the zero-crossing phase interval.

[0117] Continuing with some of the aforementioned implementation methods of rectifier circuits, during the period when the switching circuit is off, the rectified electrical signal output by the rectifier circuit is the first rectified electrical signal. Based on the circuit structure of the first rectifier unit in the rectifier circuit used to output the first rectified electrical signal, the first detection signal generation module can directly acquire the first rectified electrical signal, sample the first rectified electrical signal at intervals, and obtain the first detection signal.

[0118] In some examples, to accommodate the circuit structure requirement of the transformer circuit in the switch control circuit supplying power to the power supply, the first detection signal generation module includes a sampling submodule 411 and a control submodule 412, so as to periodically obtain the AC signal during the disconnection period from the AC line connected to the switch circuit, thereby obtaining a first detection signal reflecting the phase of the AC signal.

[0119] The sampling submodule includes at least one switch M2, which is located on the line where the data acquisition operation is performed. For example, switch M2 is located on a sampling line connected to an AC power line. Alternatively, switch M2 is located on a sampling line connected to a rectifier circuit. When switch M2 is on, the sampling submodule performs the data acquisition operation; conversely, when switch M2 is off, the sampling submodule stops performing the data acquisition operation. Therefore, performing the data acquisition operation can be considered as the process by which the sampling submodule generates a first detection signal from the acquired sampling signal; stopping the data acquisition operation can be considered as the process by which the sampling submodule cannot obtain a sampling signal. The process by which the sampling submodule performs interval data acquisition within one power frequency cycle of the AC power supply refers to the process by which switch M2 performs at least one set of on / off operations within one power frequency cycle. The set of on / off operations may occur only when the phase of the AC signal is within the zero-crossing phase interval, or only when the phase of the AC signal is outside the zero-crossing phase interval, or during the period when the phase of the AC signal moves from outside the zero-crossing phase interval into the zero-crossing phase interval, or during the period when the phase of the AC signal moves from inside the zero-crossing phase interval into outside the zero-crossing phase interval.

[0120] In some specific examples, the sampling submodule includes a rectifier bridge, a switch, and a sampling resistor. The rectifier bridge is connected to the AC power line connected to the input of the switch circuit, and connects to the switch and the sampling resistor. During the period when the switch circuit is open and the switch M2 is on, the sampling resistor HV_Resistor acquires the rectified electrical signal output by the rectifier bridge RB3 and outputs a first detection signal. When the switch is open, the sampling resistor HV_Resistor cannot output the first detection signal corresponding to the phase of the rectified electrical signal, thus outputting the first detection signal intermittently. The switch M2 is an N-type power transistor. In fact, those skilled in the art should readily understand that the switch M2 can be replaced by a P-type power transistor, a bipolar transistor, etc., depending on the actual circuit design requirements.

[0121] Therefore, the control submodule 412 is connected to the control terminal of switch M2 and is used to output a sampling control signal by detecting the first detection signal or the zero-crossing detection signal to control the switch. Here, to ensure that the sampling submodule 411 outputs the first detection signal when the phase of the current AC current falls into the zero-crossing phase interval, the control submodule 412 controls the duration of switch M2 being turned on or off by detecting the voltage of the first detection signal. The control submodule 412 outputs a sampling control signal indicating the duration of control on or off through its electrical connection with the control terminal of switch M2. The control submodule 412 presets a reference voltage interval that covers the zero-crossing voltage interval corresponding to the zero-crossing phase interval. For example, the setting of the reference voltage interval at least ensures that the upper voltage limit V1 of the reference voltage interval is greater than or equal to the upper voltage limit V2 of the zero-crossing voltage interval.

[0122] In some examples, the control submodule first controls the switch to be turned on at preset time intervals, and detects the voltage of the first detection signal during the on period. When the voltage of the first detection signal falls into the reference voltage range, the control submodule continuously outputs a sampling control signal to keep the switch in the sampling submodule always on, until the voltage of the first detection signal exceeds the reference voltage range, then controls the switch to be turned off, and controls the switch to be turned on at preset time intervals. For example, the control submodule includes a signal generator, a comparator, and a selector. The comparator compares the voltage v of the first detection signal with a voltage upper limit V1. When the voltage v of the first detection signal is greater than or equal to the voltage upper limit V1, the selector, based on the comparison result output by the comparator, connects the signal generator and the control terminal of the switch, so that the switch is controlled by the sampling control signal (such as a square wave signal) output by the signal generator and is turned on and off according to a preset on / off cycle. When the voltage v of the first detection signal is less than the voltage upper limit V1, the selector, based on the comparison result output by the comparator, connects the control terminal of the switch to a constant voltage terminal, so that the control terminal of the switch is always turned on by the constant voltage signal provided by the constant voltage terminal. Depending on the type of switch in the actual circuit design, the constant voltage terminal can be a voltage ground terminal or the output terminal of a reference voltage source.

[0123] In some other examples, the control submodule first controls the switch to be turned on at a preset time interval, and detects the voltage of the first detection signal during the on period. When the voltage of the first detection signal falls into the reference voltage range, at least one of the duty cycle and frequency of the sampling control signal is adjusted to ensure that the voltage of the first detection signal output by the sampling submodule falls into the zero-crossing voltage range. For example, the control submodule includes an adjustable signal generator and a comparator, wherein the comparator compares the voltage v of the first detection signal with the upper voltage limit V1. When the voltage v of the first detection signal is less than or equal to the upper voltage limit V1, based on the comparison result output by the comparator, the adjustable signal generator outputs a sampling control signal with a first duty cycle to the control terminal of the switch, so that the switch is controlled by the square wave control signal output by the signal generator and is turned on and off according to the period of the square wave control signal. When the voltage v of the first detection signal is greater than the upper voltage limit V1, based on the comparison result output by the comparator, the adjustable signal generator adjusts the duty cycle of the sampling control signal to a second duty cycle and outputs it to the control terminal of the switch; wherein the second duty cycle is less than the first duty cycle.

[0124] In some further examples, the control submodule outputs the sampling control signal by detecting a zero-crossing detection signal. Here, when the control submodule detects that the zero-crossing detection signal is valid, it outputs a sampling control signal to control the switch to turn off and starts a sampling interval timer; when the sampling interval timer reaches a sampling interval threshold, the control submodule adjusts the sampling control signal to control the switch to turn on.

[0125] The first detection signal output in any of the above examples is transmitted to a first zero-crossing detection module, which detects whether the voltage of the first detection signal falls within the zero-crossing voltage range and outputs a zero-crossing detection signal based on the comparison result. For example, the first zero-crossing detection module includes a comparator that compares the voltage v of the first detection signal with the upper voltage limit V2 of the zero-crossing voltage range. When the voltage v of the first detection signal is less than or equal to the upper voltage limit V2, the output zero-crossing detection signal indicates that the phase of the current alternating current is within the zero-crossing phase range; otherwise, the output zero-crossing detection signal indicates that the phase of the current alternating current is not within the zero-crossing phase range. Here, the zero-crossing detection signal level signal, according to the actual circuit design of the first zero-crossing detection module, uses a pulse width signal composed of high and low levels to describe the zero-crossing detection signal. The duration of the effective pulse width used to represent the zero-crossing phase range can be very small. In some examples, the duration of the effective pulse width of the zero-crossing detection signal is determined based on the duration for which the detection signal falls within the zero-crossing voltage range. For example, if the first detection signal is continuously output within the reference voltage range, the zero-crossing detection module obtains a zero-crossing detection signal based on the detection of the first detection signal within the zero-crossing voltage range; wherein the effective pulse width of the zero-crossing detection signal is less than or equal to the duration during which the detection signal falls within the zero-crossing voltage range. In some other examples, the effective pulse width of the zero-crossing detection signal is determined based on the operation duration of the control submodule in the shunt control module or the first detection signal generation module. For example, when the shunt control module receives a valid zero-crossing detection signal, it controls the switching unit in the selection circuit to turn on. When the switching unit is on, the selection circuit selects and switches to the first line. Thus, since there is no AC signal input in the second line, the zero-crossing detection signal changes from valid to invalid. Therefore, the effective pulse width of the zero-crossing detection signal is related to the response duration of the shunt control module and the switching unit. According to the descriptions of the above examples, the zero-crossing detection signal can be a square wave signal with a relatively long effective pulse width or a pulse signal with a relatively short effective pulse width.

[0126] The zero-crossing detection signal generated based on any of the above examples is output to the control circuit, which can output a control signal for controlling the switching circuit by means of a preset control logic designed based on the received control information about the switching circuit and the zero-crossing detection signal.

[0127] In some examples, during the period when the switching circuit is open, when the control circuit receives control information indicating that the switching circuit is open, the control circuit controls the switching circuit to be open during the period when the zero-crossing detection signal is valid. For example, the processing unit in the control circuit generates and maintains a logic signal valid based on the received control information, and when the zero-crossing detection signal is received, it outputs a control signal to the switching circuit to open using preset control logic corresponding to the two signals.

[0128] In other examples, during the disconnection of the switching circuit, when the control circuit receives control information indicating that the switching circuit should be turned on, the control circuit generates a control delay based on the zero-crossing detection signal, and controls the switching circuit to turn on when the control delay times out and the control information is received. For example, the switching circuit includes a relay. Since the relay requires a response time, the control circuit incorporates a corresponding delay timer based on the response time of the relay used. The timer starts based on the rising edge (or falling edge) of the acquired zero-crossing detection signal. The control circuit outputs a control signal indicating that the switching circuit is turned on based on the logic signal generated by the acquired control information, the zero-crossing detection signal, and the delay timeout signal, thereby ensuring that the relay avoids turning on during the peak voltage range of the AC power.

[0129] During the conduction period of the switching circuit, the first zero-crossing detection unit is short-circuited by the switching circuit. The zero-crossing detection circuit of this application also provides a second zero-crossing detection unit to reduce the chance of damage to the load and components within the switching circuit caused by controlling the switching circuit to disconnect during the peak voltage range of the AC current. In other words, the second zero-crossing detection unit provides AC phase information to the control circuit so that the control circuit can control the switching circuit to disconnect near the AC zero phase, thereby extending the service life of the switching circuit, load, etc. To this end, the second detection unit performs zero-crossing detection during the conduction period of the switching circuit to output a corresponding zero-crossing detection signal to the control circuit. Specifically, during the conduction period of the switching circuit, the second zero-crossing detection unit detects whether a second detection signal reflecting the current AC phase falls within the zero-crossing phase range and outputs a zero-crossing detection signal.

[0130] Please see Figure 9 The diagram shows a circuit structure schematic of the second zero-crossing detection unit in one embodiment. The second zero-crossing detection unit includes a second detection signal generation module 421 and a second zero-crossing detection module 422.

[0131] The second detection signal generation module generates a second detection signal reflecting the current AC phase. This second detection signal generation module may include sampling devices (groups). In some examples, during the conduction period of the switching circuit, the second detection signal generation module synchronously acquires the AC signal output by the switching circuit using the sampling devices (groups) and outputs the sampled signal as the second detection signal. In another example, continuing with some of the aforementioned rectifier circuit implementations, during the conduction period of the switching circuit, the rectified signal output by the rectifier circuit is the second rectified signal. Correspondingly, in some examples, the second detection signal generation module samples the second rectified signal using the sampling devices (groups) or directly samples the AC signal, and outputs the sampled signal as the second detection signal.

[0132] In some other examples, due to the phase-cutting limitation of the power supply unit, the phase range of the second rectified electrical signal received by the second detection signal generation module corresponds to the phase range when the aforementioned power supply unit performs phase-cutting control. In one example, the phase range selected by the power supply unit based on the power supply purpose includes a zero-crossing phase range. The second detection signal generation module outputs the second sampled signal provided by the second sampling circuit as the second detection signal; or it resamples the second sampled signal to obtain the second detection signal and outputs it. For example, the second detection signal generation module 421 includes voltage divider resistors R23 and R24, connected between the second sampling circuit 25 and the voltage ground. The second detection signal output by the second detection signal generation module 421 is the electrical signal collected from the voltage divider resistors R23 and R24. Depending on the actual circuit structure design requirements and for the purpose of circuit simplicity, the second sampling circuit and the second detection signal generation module may share all or part of the resistors, for example, sharing the resistors used for voltage division.

[0133] The second zero-crossing detection module is connected to the second detection signal generation module. It is used to detect the voltage of the second detection signal based on the zero-crossing voltage range corresponding to the zero-crossing phase range, and output the zero-crossing detection signal based on the detection result. For example, the second zero-crossing detection module includes a comparator. One input of the comparator receives the second detection signal, and the other input receives the upper voltage limit V3 of the zero-crossing voltage range. When the voltage v' of the second detection signal is lower than or equal to the upper voltage limit V3, the output second detection signal indicates that the phase of the current AC power is within the zero-crossing phase range; otherwise, the output second detection signal indicates that the phase of the current AC power does not fall within the zero-crossing phase range. As another example, the second zero-crossing detection module 422 includes two comparators. One comparator compares the voltage of the second detection signal with the voltage of the reference voltage Vref3, and the other comparator compares the voltage of the rectified signal with the reference voltage Vref4. When both comparators output logic signals indicating that the phase of the current AC power falls within the zero-crossing phase range, a zero-crossing detection signal is output.

[0134] To prevent other logic devices in the zero-crossing detection circuit from malfunctioning due to voltage disturbances regarding the zero-crossing detection signal, please refer to the following examples in some cases. Figure 10 The diagram shows a schematic of a zero-crossing detection circuit. The first zero-crossing detection unit 41 and the second zero-crossing detection unit 42 are connected to a logic unit 43. This logic unit 43 performs logical processing on the zero-crossing detection signals output by the first and second zero-crossing detection units 41 and 42 respectively, and outputs a zero-crossing detection signal that can be recognized by the control circuit 24. The logic unit 43 includes, for example, XOR processing, so that it only outputs a zero-crossing detection signal that can be recognized by the control circuit when either the first or second zero-crossing detection unit 41 outputs a zero-crossing detection signal indicating that the current AC current is in the zero-crossing phase interval.

[0135] During the conduction of the switching circuit, in some examples, when the control information received by the control circuit indicates that the switching circuit should be disconnected, the control circuit controls the switching circuit to disconnect during the validity period of the zero-crossing detection signal. For example, the processing unit in the control circuit generates and maintains a logic signal valid based on the received control information, and when the zero-crossing detection signal is received, it outputs a disconnect control signal to the switching circuit using preset control logic corresponding to the two signals.

[0136] In other examples, when the control circuit receives control information indicating that the switching circuit should be disconnected, the control circuit generates a control delay based on the zero-crossing detection signal, and controls the switching circuit to disconnect when the control delay times out and the control information is received. For example, the switching circuit includes a relay. Since the relay requires a response time, the control circuit has a built-in corresponding delay timer based on the response time of the relay used. The timer starts from the rising edge (or falling edge) of the acquired zero-crossing detection signal. Based on the logic signal generated by the acquired control information, the control logic of the zero-crossing detection signal and the delay timeout signal, the control circuit outputs a control signal indicating disconnection to the switching circuit, thereby ensuring that the relay avoids disconnection within the peak voltage range of the AC power.

[0137] In a zero-crossing detection circuit designed based on the technical solution provided in this application, the effective duration of the output zero-crossing detection signal can be very short, so short that control circuits in power-saving, standby, or sleep states may miss the response. Examples of such control circuits include circuits containing a CPU and circuits containing an enable controller. Therefore, the detection circuit of this application further includes a zero-crossing detection signal output module, which amplifies the zero-crossing detection signal output by the zero-crossing detection module or logic unit. Here, the amplification process includes voltage amplitude amplification and / or effective duration amplification. In some examples, the zero-crossing detection signal output module includes an amplifier that amplifies the voltage amplitude of the zero-crossing detection signal to match the voltage requirements for waking up subsequent control circuits.

[0138] In some other examples, the zero-crossing detection signal output module extends the effective duration of the zero-crossing detection signal. Here, the zero-crossing detection signal output module converts the zero-crossing detection signal with an effective pulse width provided by the zero-crossing detection module into a zero-crossing detection signal with a preset duration; wherein the duration of the effective pulse width is less than the preset duration.

[0139] The zero-crossing detection signal output module includes a duration extension device (group), and may even include a trigger / reset device (group) for the duration extension device (group). Examples of the duration extension device (group) include a monostable multivibrator (also known as a one-shot). Examples of the trigger / reset device (group) for the duration extension device (group) include a timer, a trigger, etc. The trigger / reset device (group) outputs a trigger signal based on the zero-crossing detection signal provided by the zero-crossing detection module, and starts a reset timer based on the zero-crossing detection signal provided by the zero-crossing detection module, and outputs a reset signal when the reset timer times out. The duration extension device (group) outputs a zero-crossing detection signal based on the trigger signal and performs a reset based on the reset signal. The duration extension device (group) outputs the zero-crossing detection signal based on a preset duration to achieve the purpose of extending the duration. The preset duration can be a fixed value, or it can be determined based on the time interval between the trigger signal and the reset signal of the duration extension device (group).

[0140] Taking the zero-crossing detection signal output module receiving only the first zero-crossing detection signal provided by the first zero-crossing detection module as an example, if the first zero-crossing detection signal received by the trigger / reset device (group) is a pulse signal, then the trigger / reset device (group) outputs a trigger signal to trigger the duration extension device (group) to output a valid zero-crossing detection signal within a preset duration; wherein the preset duration is longer than the duration of the first zero-crossing detection signal; simultaneously, the trigger / reset device (group) performs a reset timing based on the first zero-crossing detection signal, and outputs a reset signal when the reset timing expires, so as to reset the duration extension device (group). The duration of the reset timing is greater than or equal to the preset duration provided by the duration extension device (group), and must be less than the power frequency period.

[0141] Taking the zero-crossing detection signal output module receiving only the second zero-crossing detection signal provided by the second zero-crossing detection module as an example, when the zero-crossing detection signal received by the duration extension device (group) from the second zero-crossing detection module is a pulse signal, the duration extension device (group) outputs a zero-crossing detection signal with an effective pulse width of a preset duration; wherein the preset duration is greater than the duration of the pulse signal (i.e., the duration of the effective pulse width) and less than the power frequency period. The duration extension device (group) automatically resets after outputting the zero-crossing detection signal with an effective pulse width of the preset duration.

[0142] Taking the zero-crossing detection signal output module, which includes the aforementioned logic units, the first trigger / reset device (group) corresponding to the first zero-crossing detection module, the second trigger / reset device (group) corresponding to the second zero-crossing detection module, and the duration extension device (group) as an example, please refer to [link to relevant documentation]. Figure 20The diagram shows a schematic of the zero-crossing detection circuit in one embodiment. The output of the first zero-crossing detection module is connected to a first trigger / reset device (group), the output of the second zero-crossing detection module is connected to a second trigger / reset device (group), the two inputs of the logic unit are respectively connected to the first trigger / reset device (group) and the second trigger / reset device (group), and the output of the logic unit is connected to the duration extension device (group). Here, during the period when the switching circuit is open, the second zero-crossing detection module does not output a second zero-crossing detection signal. Correspondingly, the output of the second trigger / reset device (group) is considered to output a second reset signal. When the first zero-crossing detection module outputs a first zero-crossing detection signal (such as a pulse), the second zero-crossing detection module outputs a second reset signal. When the first trigger / reset device (group) outputs a first trigger signal to the logic unit and starts a first reset timing, the logic unit outputs a trigger logic signal corresponding to the first trigger signal according to the preset control logic of the first trigger signal, the first reset signal, the second trigger signal, and the second reset signal. The duration extension device (group) outputs a zero-crossing detection signal of a preset duration (i.e., a zero-crossing detection signal with an effective pulse width of a preset duration) based on the trigger logic signal. When the reset timing expires, the first trigger / reset device (group) outputs a first reset signal, and the logic unit outputs a reset logic signal corresponding to the first reset signal according to the control logic, and then the duration extension device (group) resets. During the conduction period of the switching circuit, the first zero-crossing detection module does not output the first zero-crossing detection signal. Correspondingly, the output terminal of the first trigger / reset device (group) is regarded as outputting the first reset signal. When the second zero-crossing detection module outputs the second zero-crossing detection signal (such as a pulse signal), the second trigger / reset device (group) outputs the second trigger signal to the logic unit and starts the second reset timing. The logic unit outputs the trigger logic signal corresponding to the second trigger signal according to the preset control logic of the first trigger signal, the first reset signal, the second trigger signal, and the second reset signal. The duration extension device (group) outputs the zero-crossing detection signal of the preset duration (i.e., the zero-crossing detection signal with an effective pulse width of the preset duration) based on the trigger logic signal. When the reset timing expires, the second trigger / reset device (group) outputs the second reset signal. The logic unit outputs the reset logic signal corresponding to the second reset signal according to the control logic, and then the duration extension device (group) resets.

[0143] Utilizing the aforementioned switch control circuit, this application also provides a smart switch. The smart switch can be installed on an indoor AC power line. The AC power line transmits AC power to a load. The smart switch connects to the AC power line and provides a conductive carrier for the AC power to return to ground, thereby controlling the opening or closing of the power supply circuit for the corresponding load. The load includes lights and any terminal electrical appliances plugged into a power socket. Examples of terminal electrical appliances include: power adapters, air conditioners, refrigerators, televisions, kitchen appliances, etc. Furthermore, the smart switch can also output control commands to the terminal electrical appliances it communicates with, based on pre-configured settings; examples of terminal electrical appliances include: smart curtains, air conditioners, televisions, rice cookers, robot vacuum cleaners, etc.

[0144] Please see Figure 11 The diagram shows a schematic of the framework structure of a smart switch in one embodiment. The smart switch includes a switching circuit 51, a rectifier circuit 52, and a switching control circuit 53. The switching control circuit can be adapted according to the aforementioned switching control circuit and the actual circuit design of the switching circuit and rectifier circuit.

[0145] Please see Figure 12The diagram shows a circuit structure schematic of a smart switch in one embodiment. The switch control circuit includes a transformer circuit 531, a power management circuit 532, a first self-powered circuit 534, and a first sampling circuit 533 for providing internal power during the disconnection of the switch circuit 51. The power management circuit 532, in which the circuit module for controlling the transformer circuit 531 during the disconnection of the switch circuit 51 includes an adjustment module 541 and a second control module 542'. The switch control circuit also includes a power management circuit 532, a second sampling circuit 537, a selection circuit 535, and a second self-powered circuit 538 for providing internal power during the conduction of the switch circuit 51. The power management circuit 532, in which the circuit module for continuously supplying power to the power supply during the conduction of the switch circuit 51 includes a second protection module 544, an output module 543, and a branch control module 545. The switching control circuit further includes an energy storage circuit 540, located on the output side of the power supply. This energy storage circuit filters the power supply signal and maintains the output voltage of the power supply when the voltage of the power supply signal decreases. For example, during the switching instant of the switching circuit between open and closed states, the energy storage circuit 540 maintains the output power supply signal. Similarly, during the switching of the selection circuit to the first line, the energy storage circuit 540 maintains the output power supply signal. The switching control circuit also includes a first voltage adjustment circuit 539 for matching the power supply voltage of the control circuit 536, and a second voltage adjustment circuit 551 for matching the power supply voltage of the switching circuit 51. The first voltage adjustment circuit 539 and the second voltage adjustment circuit 551 may be circuits incorporating low dropout regulators (LDOs).

[0146] Here, the switching circuit is connected to the live wire for controlled on / off switching. When disconnected, the load on the circuit where the smart switch is located is in a stopped state; when connected, the load can enter a working state under the drive of its driving circuit. The stopped state refers to the state in which the load cannot receive AC power; for example, an LED light is off when the switching circuit is off. The working state refers to the state in which the load receives AC power and operates through its internal circuitry to achieve its intended use; for example, an LED light can be on when the switching circuit is on. Here, the working state is not limited to a single state but is adjusted according to actual control commands. For example, the working state of an LED light includes not only the on state but also the state after adjusting brightness and color. Similarly, the working states of a television include standby state and playback state.

[0147] In some examples, the switching circuit includes a relay, which operates powered by the power supply. The switch terminals of the relay are connected to an AC power line, and the control terminal is connected to the control circuit in the switch control circuit. When the control circuit controls the switching circuit to turn on based on control information, the control circuit can achieve relay on-state by increasing the supply current to the relay control terminal; when the control circuit controls the switching circuit to turn off based on control information, the control circuit can achieve relay off-state by decreasing the supply current to the relay control terminal.

[0148] The rectifier circuit is connected to the switching circuit and is used to rectify the connected AC power and output a rectified signal during the switching circuit's open and closed periods, respectively. The rectified signal output by the rectifier circuit can be obtained by rectifying the AC signal through a half-wave or full-wave rectifier bridge. To ensure uninterrupted output of the rectified signal during both the open and closed periods of the switching circuit, the rectifier circuit can be connected to the live wire on one side of the switching circuit's input terminal, so that the AC signal can be shunted to obtain a rectified signal during both periods.

[0149] In some implementations, such as Figure 12 As shown, the rectifier circuit includes a first rectifier unit 521. The first rectifier unit 521 is connected to the AC power line connected to the input terminal of the switching circuit, and is used to rectify the AC power flowing to the switching circuit during the switching circuit being open and output a first rectified electrical signal; wherein, the first rectified electrical signal is a rectified electrical signal provided by the rectifier circuit, and the first rectified electrical signal serves as the power supply input for the internal power supply of the switch control circuit during the switching circuit being open.

[0150] To ensure the load remains stationary during the disconnection of the switching circuit, the voltage range of the AC signal received by the first rectifier unit should be lower than the operating voltage range required for the load to operate. Technicians can ensure the load remains stationary when the first rectifier unit outputs the first rectified signal by selecting the component parameters in the first rectifier unit. In some examples, the first rectifier unit includes a rectifier bridge and a filter capacitor. Examples of the rectifier bridge include a half-wave rectifier bridge or a full-wave rectifier bridge. Taking a half-wave rectifier bridge as an example, the output terminal of the rectifier bridge in the first rectifier unit 521 is connected to a filter capacitor, and the other end of the filter capacitor is grounded.

[0151] The first rectified electrical signal output from the first rectifier unit is transmitted to the transformer circuit in the switch control circuit. The switch control circuit can control the transformer circuit to convert the received first rectified electrical signal into energy according to any of the examples mentioned above, so as to obtain a power supply for supplying power to the internal electrical components of the intelligent switch, such as the power management circuit and the control circuit.

[0152] by Figure 12 Taking the circuit structure of the intelligent switch shown as an example, the circuit structure and working process of the first rectifier unit 521 and the switch control circuit are illustrated as follows: The half-wave rectifier bridge of the first rectifier unit 521 is connected to the live wire of the input terminal of the switch circuit. The output terminal of the half-wave rectifier bridge is connected to the primary input unit in the transformer circuit 531 via a filter capacitor. Utilizing the transformer processing of the primary input unit and the secondary output unit, the secondary output unit outputs a power supply signal as the power supply output terminal. The primary input unit is grounded through the control unit in the power management circuit. The secondary output unit is also grounded to reduce internal losses during energy conversion. The control unit includes a grounded adjustment module 541 and a second control module 542' for controlling the on / off state of the adjustment module 541. The secondary output unit includes a secondary winding grounded to voltage and a unidirectional conduction module connected to the output terminal of the secondary winding. A first sampling circuit 533 is provided on the power supply side of the secondary output unit. It collects the power supply voltage of the power supply and generates a first sampling signal FB1, and transmits the first sampling signal to the second control module 542'. At the same time, the second control module 542' also obtains the third sampling signal CS collected from the primary input unit through the third sampling circuit 552.

[0153] The working process of the above circuit structure is illustrated below: During the off-state of the switching circuit, the AC signal is half-wave rectified and low-pass filtered by the rectifier diode in the first rectifier unit 521, and then output as the first rectified signal to the transformer circuit. The mutual inductance windings in the primary input unit and secondary output unit of the transformer circuit 531 transform the first rectified signal. Since the secondary winding in the secondary output unit is grounded, the diodes and capacitors in the unidirectional conduction module ensure that the converted power supply is output unidirectionally and stably. The second control module 542' controls the on / off state of the adjustment module 541 by detecting the first sampling signal FB1 and the third sampling signal CS. Specifically, the second control module 542' performs low-pass filtering on the voltage of the acquired first sampling signal to obtain a detection signal COMP corresponding to the first sampling signal, and outputs a clock signal based on the voltage of the detection signal COMP; wherein the frequency of the clock signal is related to the voltage of the detection signal COMP. Meanwhile, the detection signal COMP is either directly used as COMP_CS, or processed according to a preset ratio and converted into COMP_CS for comparison with the third sampling signal CS, and a corresponding logic signal is generated based on the comparison result. When the comparison result obtained by the second control module 542' through comparing CS and COMP_CS indicates that the adjustment module 541 should be disconnected, the adjustment module 541 is disconnected; when the comparison result obtained by the second control module 542' through comparing CS and COMP_CS indicates that the adjustment module 541 should be turned on, the adjustment module 541 is turned on.

[0154] It should be noted that, in combination Figure 12 The description is for illustrative purposes only; in fact, according to Figure 2 The connection relationship and working process of the first control module and the adjustment module described therein can also achieve a control method similar to that of the second control module, which will not be described in detail here. Furthermore, according to... Figure 18 The second control module and the third protection module described therein can not only achieve stable power supply to the secondary output unit by controlling the adjustment module with the second control module, but also provide circuit protection for the normal operation of the internal electrical components with the third protection module, which will not be described in detail here.

[0155] During the conduction of the switching circuit, in order to prevent the first rectifier unit from failing to output the first rectified electrical signal due to a short circuit, in some embodiments, the switching circuit includes a shunt device (such as a resistor) so that the first rectifier unit receives shunt AC power during the conduction of the switching circuit.

[0156] In some embodiments, to ensure continuous power supply from the internal power source of the switch control circuit during the conduction of the switch circuit, the switch control circuit switches the switch circuit and load between a first line and a second line in a time-division multiplexing manner. This allows the rectifier circuit to rectify the received AC signal and output a corresponding rectified signal (hereinafter referred to as the second rectified signal). To facilitate easier conversion between the second rectified signal and the output power of the power supply, the rectifier circuit further includes a second rectifier unit connected to the live wire connected to the output terminal of the switch circuit. For example, the second rectifier unit and the aforementioned first rectifier unit are located at opposite ends of the switch circuit.

[0157] The second rectifier unit is used to rectify the input AC signal and output a second rectified signal during the conduction of the switching circuit. The second rectifier unit can be connected to the AC power line connected to the output terminal of the switching circuit. The second rectifier unit includes a rectifier bridge and a filter capacitor. The rectifier bridge may be a half-wave rectifier bridge or a full-wave rectifier bridge. The filter capacitor is connected between the output terminal of the rectifier bridge and ground to perform low-pass filtering on the rectified signal output by the rectifier bridge to obtain the second rectified signal. The second rectified signal is another rectified signal provided by the rectifier circuit.

[0158] Still Figure 12 As shown, during the time-sharing switching of the AC power line containing the switching circuit and the load to the second line by means of the switching control circuit, the second rectifier unit 522 outputs a second rectified electrical signal. Simultaneously, to prevent the first and second rectified electrical signals from being output simultaneously by the second rectifier unit 522 and the first rectifier unit 521, thus causing excessively high supply voltage within the switching control circuit, the conduction voltage of the rectifier bridge in the first rectifier unit 521 is higher than the conduction voltage of the rectifier bridge in the second rectifier unit. Correspondingly, the upper limit of the preset reference voltage range in the switching control circuit should be lower than the conduction voltage of the rectifier bridge in the first rectifier unit 521. When the switching control circuit detects that the voltage of the second rectified electrical signal reaches the upper limit of the reference voltage range, it switches the AC power line containing the switching circuit and the load to the first line. The upper voltage limit may correspond to the upper limit of the reference voltage range used for phase-cutting control in the aforementioned power supply unit.

[0159] by Figure 12Taking the circuit structure shown as an example, during the conduction of the switching circuit, the selection circuit 535 in the switch control circuit is connected to the AC line where the switching circuit 51 is located, and selects to switch the load and the switching circuit to the second line to form a power loop. The second rectifier unit 522 obtains the AC signal from the second line and converts it into a second rectified signal, then outputs it to the output module 543 in the power supply unit so that the second rectified signal can be directly used as the power supply signal output by the power supply. At the same time, the second sampling circuit 537 in the switch control circuit collects a second sampling signal reflecting the voltage of the second rectified signal and provides it to the branch control module 545 in the power supply unit. When the branch control module 545 detects that the voltage of the second sampling signal reaches the upper limit of the preset reference voltage range, it controls the switch unit M1 in the selection circuit 535 to turn on, so that the switch circuit switches from accessing the second line to accessing the first line and starts timing. When the timing duration reaches the timing threshold, the branch control module 545 controls the switch unit M1 in the selection circuit 535 to turn off, and according to the current phase range of the AC (-180-0 degrees or 0-180 degrees), the selection circuit 535 delays or immediately switches from the first line to the second line. When the voltage difference across the rectifier circuit is greater than its conduction voltage, the power-on circuit of the second line is turned on. The duration of the time is related to the AC power frequency and the discharge time of the capacitor in the second rectifier unit 522.

[0160] In some cases, to prevent excessive voltage during the instantaneous conduction of the switching circuit, the power supply unit further includes a first protection module 546, which is connected in parallel with the branch control module 545. This module detects the voltage of the electrical signal reflecting the AC signal flowing through the second line, and when the detected voltage exceeds a preset protection voltage threshold, controls the selection circuit to switch from the second line to the first line. The electrical signal reflecting the AC signal flowing through the second line can be either a second sampling signal or a second detection signal. For example, when the voltage of the second sampling signal provided by the output of the second sampling circuit exceeds the preset protection voltage threshold, the first protection module 546 controls the selection circuit 535 to switch from the second line to the first line; simultaneously, or with a slight delay, the branch control module 545 controls the selection circuit 535 to switch from the second line to the first line and maintains this switch for the specified duration.

[0161] Based on the aforementioned smart switches, the switch control circuit in the smart switch also performs zero-crossing detection during at least one of the switching circuit's open and closed periods. Here, the zero-crossing detection circuit in the smart switch is the same as or similar to the zero-crossing detection circuit mentioned above in this application, and will not be described in detail here.

[0162] Please see Figure 13This is a schematic diagram of the circuit structure of a smart switch in one embodiment. Taking the first zero-crossing detection unit in the aforementioned zero-crossing detection circuit as an example during the switch circuit's open state, the operation process of the smart switch is described as follows: (Combined with...) Figure 13 During the period when the switching circuit is open, the control unit in the first rectifier unit 521, the transformer circuit 531 and the power management circuit 532 in the smart switch provide power to the electrical components inside the smart switch, which will not be described in detail here. Under stable power supply, the first detection signal generation module 561 in the first zero-crossing detection unit directly acquires the AC signal flowing through the AC line during the disconnection of the switching circuit 51 to obtain the first detection signal; the control submodule 565 in the first zero-crossing detection unit controls the first detection signal generation module 561 to acquire the first detection signal, for example, the control submodule 565 controls the first detection signal generation module 561 to acquire the first detection signal according to a preset time interval or controls the first detection signal generation module 561 to acquire the first detection signal throughout the entire cycle; the first zero-crossing detection module 562 detects the voltage of the first detection signal during each acquisition period to determine whether the phase of the current AC power is within the zero-crossing phase interval, and outputs the zero-crossing detection signal according to the detection result; in some embodiments, when it is determined by detection that the phase of the current AC power does not fall within the zero-crossing phase interval, the control submodule 565 does not adjust the acquisition time interval, and when it is determined by detection that the phase of the current AC power falls within the zero-crossing phase interval, the control submodule 565 adjusts the acquisition time interval to extend the acquisition duration. The control circuit 536 receives the zero-crossing detection signal and generates a delay timer for the control information based on the preset response delay of the switching circuit and the zero-crossing detection signal. When the control circuit 536 receives the control information to turn on the switching circuit, it starts the delay timer until it receives the zero-crossing detection signal indicating that the phase of the current AC power is within the zero-crossing phase interval, and then controls the switching circuit 51 to turn on.

[0163] Taking the second zero-crossing detection unit in the aforementioned zero-crossing detection circuit as an example during the conduction period of the switching circuit, the working process of the smart switch is described as follows: (Combined with...) Figure 13During the conduction period of the switching circuit, the second rectifier unit 522 in the smart switch and the power supply unit in the power management circuit provide power to the internal electrical components of the smart switch, which will not be described in detail here. Under the stable power supply, the second detection signal generation module 563 in the second zero-crossing detection unit collects the second rectified electrical signal to obtain the second detection signal, and the second zero-crossing detection module 564 detects the voltage of the second detection signal to determine whether the phase of the current AC power is within the zero-crossing phase interval, and outputs the zero-crossing detection signal according to the detection result. The control circuit 536 receives the zero-crossing detection signal and generates a delay timer for the control information based on the preset response delay of the switching circuit 51 and the zero-crossing detection signal. When the control circuit 536 receives the control information to control the switching circuit to conduct, it starts the delay timer until it receives the zero-crossing detection signal indicating that the phase of the current AC power is within the zero-crossing phase interval, and controls the switching circuit to conduct.

[0164] It should be noted that the second detection signal generation module 563 can also directly acquire the AC signal flowing out of the switching circuit and obtain the second detection signal during the selection of the second line by the selection circuit.

[0165] It should also be noted that, since the second rectifier unit outputs the second rectified electrical signal within a preset reference voltage range, in order to take into account both the zero-crossing detection signal and the power supply, the reference voltage range can cover the zero-crossing voltage range. The reference voltage range thus ensures that during the period when the second rectifier unit outputs the second rectified electrical signal, the corresponding second zero-crossing detection unit can output the second zero-crossing detection signal.

[0166] It should also be noted that the descriptions of the circuits in the smart switch are merely examples. For instance, depending on the actual circuit design requirements, the corresponding circuit parts in the above examples can be replaced by any other example in the aforementioned switch control circuit, etc., which will not be described in detail here.

[0167] This application also provides a switching control method for a smart switch. The switching control method can be executed by the aforementioned switching control circuit in conjunction with a rectifier circuit provided in the smart switch; or by other switching control circuits or smart switches capable of executing the switching control method.

[0168] Please see Figure 14 The diagram shows a flowchart of a switching control method during the disconnection of a switching circuit. In step S110, during the disconnection of the switching circuit, a first sampling signal reflecting the power supply provided by the secondary output unit of a transformer circuit is acquired, and the current in the primary input unit of the transformer circuit is controlled based on the first sampling signal.

[0169] The transformer circuit supplies power to the power supply via the rectified electrical signal provided by the rectifier circuit. The circuit structure of the transformer circuit can be as follows: Figure 2 The circuit structures of the transformer circuits shown and described are similar or identical, and will not be detailed here. Furthermore, the first sampling signal originates from the aforementioned... Figure 2 The circuit structures of the first sampling circuit shown and described are similar or identical, and will not be detailed here.

[0170] In some implementations, controlling the current in the primary-side input unit of the transformer circuit based on the first sampled signal includes: comparing the voltage of the first sampled signal with a preset reference voltage, and controlling the on / off state or current change of the line where the primary-side input unit is located based on the comparison result. Here, the voltage of the first sampled signal is compared with the preset reference voltage to obtain a logic signal, and the current in the line where the primary-side input unit is located is controlled according to the detection logic expressed by the logic signal.

[0171] In some examples, analog devices within the logic devices and auxiliary logic devices of the switch control circuit represent the detection logic between the first sampled signal and the reference voltage. The voltage of the first sampled signal is compared with a preset reference voltage, and the current in the primary-side input unit is controlled based on the comparison result. The reference voltage can be a reference voltage range or a reference voltage value set based on the supply voltage of the power supply. In a specific example, the control unit in the aforementioned switch control circuit includes a circuit structure capable of generating corresponding detection and control signals according to the above process, which will not be detailed here.

[0172] In other embodiments, controlling the current in the primary-side input unit of the transformer circuit based on the first sampling signal includes controlling the on / off state or current change of the line where the primary-side input unit is located based on the error between the voltage of the first sampling signal and a preset reference voltage. Here, by detecting the error between the voltage of the first sampling signal and the preset reference voltage, the drift of the actual output voltage of the power supply can be described, and the current in the line where the primary-side input unit is located is controlled according to an analog or digital signal representing this drift. In a specific example, the control unit in the aforementioned switch control circuit includes a circuit structure that can generate corresponding detection signals and control signals according to the above process, which will not be detailed here.

[0173] According to the detection method mentioned in any of the above examples, the way the switch control circuit controls the current of the line where the primary-side input unit is located includes, but is not limited to, controlling the on / off state or current change of the line. In some examples, the control method includes, but is not limited to, controlling at least one of the following: the frequency of current change, the on / off frequency, the on duration, and the off duration of the line where the primary-side input unit is located.

[0174] Here, depending on whether the received detection signal is a logic signal or an error signal, and the corresponding circuit structure provided by the control unit in the switch control circuit, at least one of the on / off frequency, on-time, and off-time of the adjustment module located on the primary input unit line is controlled; or the frequency of change of the adjustment module's regulating current is controlled. In some examples where the detection signal is a logic signal, taking the adjustment of the adjustment module's on / off state as an example, the control submodule in the switch control circuit adjusts the duty cycle of its internal PWM signal based on the detection result of the supply voltage being too high or too low, thereby adjusting the ratio of the on-time and off-time of the adjustment module, and thus adjusting the supply voltage output by the transformer circuit. In other examples where the detection signal is a logic signal, taking the adjustment of the adjustment module's on / off state as an example, the control submodule in the switch control circuit adjusts the on / off frequency of the adjustment module based on the detection result of the supply voltage being too high or too low, thereby adjusting the supply voltage output by the transformer circuit. For example, the control submodule in the switching control circuit includes an adjustable frequency divider. The frequency divider is adjusted based on the received detection signal to change the frequency of the control signal, and the switching frequency of the regulating module is controlled based on the changed frequency control signal. In some further examples where the detection signal is a logic signal, taking the adjustment of the current change of the regulating module as an example, the control submodule adjusts the duty cycle of the internal PWM signal based on the detection result indicating that the supply voltage is too high or too low, where the duration of the high and low levels of the PWM signal corresponds to the duration of one selected circuit and the other selected circuit selected by the regulating module, respectively. The current regulation scheme provided by any of the above examples achieves the goal of stabilizing the supply voltage output by the transformer circuit.

[0175] In some examples where the detection signal is an error signal, taking the adjustment of the switching on / off state of the regulating module as an example, the control submodule contains a timer. The timer uses the voltage of the detection signal as a reference voltage and times at least one of the durations of the on-state and off-state of the regulating module. Then, based on the timeout signal generated at the corresponding timeout moment, it controls the regulating module to switch between the on-state and off-state. The timer can be exemplified as a timing circuit including a capacitor and its charging / discharging circuit; or as a timing circuit including a clock generator, a counter, and a digital-to-analog converter. In further examples where the detection signal is an error signal, taking the adjustment of the current change of the regulating module as an example, the control submodule adjusts the duty cycle of the internal PWM signal according to the error voltage represented by the detection signal. The durations of the high and low levels of the PWM signal correspond to the durations of one selected circuit and the other selected circuit selected by the regulating module, respectively. The current adjustment scheme provided by any of the above examples achieves the goal of stabilizing the supply voltage output by the transformer circuit.

[0176] In some other embodiments, the step of the switch control circuit controlling the current in the primary-side input unit based on the first sampling signal further includes: acquiring a third sampling signal that reflects the line electrical signal in the line where the primary-side input unit is located; and controlling the current flowing through the primary-side input unit based on the first sampling signal and the third sampling signal.

[0177] Here, based on the circuit structure of the control unit in the switch control circuit, please refer to some examples. Figure 16 As shown, the control unit includes an adjustment module 121 and a second control module 125, and the switch control circuit further includes a third sampling circuit 16. The third sampling circuit 16 collects the voltage or current signal of the line where the primary-side input unit is located. For example, the third sampling circuit 16 includes a controlled switch and a sampling resistor. The input terminal of the controlled switch is connected to the input terminal of the adjustment module 121, the output terminal of the controlled switch is grounded through the sampling resistor, and the control terminal of the controlled switch is connected to the control terminal of the adjustment module 121 to synchronously receive the control from the second control module 125. The adjustment module 121 is similar to the aforementioned... Figure 2The circuit structure and execution process of the adjustment module 121 shown are the same or similar, and will not be described in detail here. The second control module 125 controls the adjustment module 121 to be turned on based on the first sampling signal FB1, and controls the adjustment module 121 to be turned off based on the first sampling signal FB1 and the third sampling signal CS. In some more specific examples, the second control module 125 controls the on-time of the adjustment module 121 based on the first sampling signal, and controls the off-time of the adjustment module 121 based on the first sampling signal FB1 and the third sampling signal CS. For example, the second control module 125 adjusts the response time for performing the corresponding turn-on or turn-off control operation by adjusting the frequency of the internal clock signal, so as to adjust the corresponding turn-on and turn-off times by changing the response time; and the second control module 125 determines the turn-on time by detecting the changes in electrical signals on both sides of the primary input unit and the secondary output unit, that is, by comparing the voltage between the third sampling signal CS and the COMP_CS signal obtained based on the first sampling signal, thereby adjusting the turn-off time; and the second control module 125 determines the turn-off time by monitoring the changes in electrical signals output by the secondary output unit, that is, by comparing the voltage of the first sampling signal FB1 with the preset reference voltage, thereby adjusting the turn-on time.

[0178] In other examples, the step of controlling the current flowing through the primary-side input unit based on the first sampling signal and the third sampling signal includes: controlling the line where the primary-side input unit is located to be turned on based on the first sampling signal, and controlling the line where the primary-side input unit is located to be turned off based on the first sampling signal and the third sampling signal.

[0179] Please see Figure 17 and 18 , among which, according to Figure 17The circuit structure shown illustrates that the adjustment module achieves current change by adjusting the on / off state of the line containing the primary input unit. For this purpose, the second control module 125' includes a turn-on control sub-circuit, a turn-off control sub-circuit, and a control logic sub-circuit. The turn-on control sub-circuit performs low-pass filtering on the voltage of the acquired first sampled signal to obtain a detection signal COMP corresponding to the first sampled signal, and outputs a clock signal based on the voltage of the detection signal COMP; wherein the frequency of the clock signal is related to the voltage of the detection signal COMP. Using the clock signal as the clock reference for the control logic sub-circuit to respond to the received logic signal, the control logic sub-circuit monitors the first logic signal indicating that the adjustment module should be turned off based on the clock signal while maintaining the adjustment module on. Simultaneously, the detection signal COMP is also directly output as COMP_CS to the turn-off control sub-circuit, or processed according to a preset ratio and converted into COMP_CS before being output to the turn-off control sub-circuit. The disconnection control subcircuit outputs the logic signal corresponding to the comparison result of the third sampling signal CS and COMP_CS to the control logic subcircuit; wherein, when the logic signal corresponding to the comparison result represents the first logic signal that causes the adjustment module to disconnect, the control logic subcircuit controls the adjustment module to disconnect based on the first logic signal and the clock signal; when the logic signal corresponding to the comparison result does not represent the first logic signal, the control logic subcircuit controls the adjustment module to turn on based on the preset second logic signal and the clock signal.

[0180] It should be noted that the on and off operations of the aforementioned adjustment module can also be replaced by switching operations between multiple lines. Each line has resistors of different resistance values ​​to change the current flowing through the primary-side input unit based on the first and second logic signals. Details will not be elaborated here.

[0181] and Figure 17 Different, please refer to Figure 18 The control unit includes a third protection module, an adjustment module, and a second control module. The adjustment module regulates the current in the line containing the primary input unit by switching it on and off; this will not be described in detail here.

[0182] The second control module controls the adjustment module to be turned on and off accordingly. In some examples, Figure 18 The second control module 125 shown can be connected with Figure 17 The second control module 125' shown is similar, but the difference lies in that... Figure 18At least some of the electrical components in the second control module 125” shown switch between an inactive state and an active state based on the protection logic signal generated by the third protection module 124. The inactive state includes, but is not limited to: a state in which at least some electrical components are not responding to input signals under the enable control of the protection logic signal, or a state in which at least some electrical components are unable to operate under the power supply control of the protection logic signal. In some more specific examples, at least one of the conduction control sub-circuit, the disconnection control sub-circuit, and the control logic sub-circuit in the second control module 125” includes an enable terminal, through which the protection logic signal is received. The corresponding sub-circuit switches between an active state and an inactive state based on whether the protection logic signal is active or inactive, thereby controlling the adjustment module to be turned on and off when all sub-circuits are in an active state; and controlling the adjustment module 121 to be disconnected when at least one sub-circuit is in an inactive state. For example, the conduction control subcircuit includes an enable terminal and receives a protection logic signal. Controlled by the protection logic signal, when the conduction control submodule is in the working state, the conduction control subcircuit outputs a clock signal corresponding to the first sampled signal; when the conduction control submodule is in the non-working state, the conduction control subcircuit outputs no clock signal. As another example, the disconnection control subcircuit includes an enable terminal and receives a protection logic signal. Controlled by the protection logic signal, when the disconnection control subcircuit is in the working state, the disconnection control subcircuit outputs a corresponding logic signal based on the comparison result of the third sampled signal CS and COMP_CS; when the disconnection control submodule is in the non-working state, the disconnection control subcircuit maintains the output of a first logic signal indicating that the adjustment module is disconnected. For example, the control logic sub-circuit includes an enable terminal and receives a protection logic signal. Under the control of the protection logic signal, when the control logic sub-circuit is in the working state, the control logic sub-circuit controls the adjustment module to be disconnected or turned on based on the received first logic signal or second logic signal; when the control logic sub-circuit is in the non-working state, the control logic sub-circuit maintains the adjustment module disconnected.

[0183] Therefore, the switch control method further includes the steps of: detecting an electrical signal reflecting the power supply signal of the power supply, and providing circuit protection for the power management circuit based on the detection result. Here, in conjunction with... Figure 18During the switching circuit's on / off cycle, the third protection module 124 protects some electrical components in the power management circuit by detecting the first sampling signal so that the line containing the primary-side input unit is disconnected during the circuit protection period. Here, during the switching circuit disconnection period, the third protection module 124 determines whether the power supply is overvoltage and / or overloaded by detecting the first sampling signal or the detection signal COMP, and outputs a protection logic signal corresponding to the detection result. The circuit structure and operation of the third protection module are the same as or similar to the third protection module in the aforementioned switch control circuit, and will not be detailed here. Taking the power supply under light load as an example, the third protection module 124 detects whether the first sampling signal is higher than a preset overvoltage protection threshold. If so, it outputs a valid first protection logic signal, causing the sub-circuit in the corresponding second control module 125” to enter a non-operating state based on the valid first protection logic signal; the third protection module 124 outputs an invalid first protection logic signal based on the real-time detection result of the first sampling signal and the preset overvoltage reset logic, thereby restoring the second control module 125” to the operating state. The overvoltage reset logic includes at least one of the following: a reset logic set based on the detection result, or a reset logic set based on a preset timing duration. For example, during a period of heavy load on the power supply, the third protection module 124 detects whether the first sampling signal is higher than a preset overload protection threshold. If so, it outputs a valid second protection logic signal, causing the sub-circuit in the corresponding second control module 125” to enter a non-operating state based on the valid second protection logic signal. The third protection module 124 outputs an invalid second protection logic signal based on the detection result of the first sampling signal in real time and the preset overload reset logic, thereby restoring the second control module 125” to the operating state. The overload reset logic includes at least one of the following: a reset logic set based on the detection result, or a reset logic set based on a preset timing duration.

[0184] In other examples, the protection logic signal generated by the third protection module controls the regulating module to remain in an open state (not shown). For example, the third protection module is connected to the control terminal of a switch in the regulating module, and the corresponding switch remains open while the third protection module outputs a protection logic signal.

[0185] With the stable power supply provided in step S110, the control circuit in the switch control circuit can execute step S120 during the period when the switch circuit is open.

[0186] In step S120, during the period when the switching circuit is open, the switching circuit is controlled to be turned on after receiving a control message.

[0187] Here, the control circuit in the switch control circuit relies on the power supply provided by the transformer circuit to perform corresponding control operations. For example, the control circuit uses the electrical energy provided by the power supply to continuously monitor whether control information is received, so as to control the switch circuit to conduct. Alternatively, the control circuit uses the electrical energy provided by the power supply to continuously monitor whether control information is received, so as to output control signals to the pre-configured air conditioner according to the air conditioning and temperature indicated in the control information.

[0188] In some examples, the control circuit provides a human-machine interface module for receiving user operations to obtain the control information. Examples of such human-machine interface modules include an interactive panel with a touch medium, including but not limited to: a touchscreen, a button, and a photosensitive device. In still other examples, the control circuit also provides a communication module for receiving and transmitting wireless signals containing control information. Examples of such communication modules include at least one of the following: short-range communication modules such as RF communication modules, WiFi communication modules, infrared communication modules, and Bluetooth communication modules; wide-area network communication modules capable of accessing fiber optic or broadband networks; and communication modules that utilize a SIM card to access mobile networks. These examples can be combined or configured individually in the interaction unit. For example, the interaction unit includes a button for controlling a switching circuit and a wireless communication module for acquiring wireless signals. The interaction unit determines that it has received control information to turn on the switching circuit by monitoring the pulse signal generated by the button, and acquires the carried control information by demodulating and decoding the wireless signal. Here, the control information acquired using the wireless communication module can include control information for turning on the switching circuit, control information for controlling the switching circuits on other lines, and control information for controlling intelligent electrical appliances to adjust, switch on, etc. The control circuit converts the obtained control information into control signals that can be recognized by the corresponding electrical components or switching circuits and outputs them.

[0189] Please see Figure 15 The diagram shows a flowchart of a switch control method during the conduction of a switch circuit. The method further includes step S130: during the conduction of the switch circuit, power is continuously supplied to the power supply via a received rectified electrical signal.

[0190] In order to allow the AC power output from the switching circuit to enter the rectifier circuit, in some embodiments, the switching control circuit connects two shunt lines to the output terminal of the switching circuit. One of the shunt lines is connected to the rectifier circuit, so that the switching control circuit can receive the rectified signal during the conduction of the switching circuit and continuously supply power to the power supply through the rectified signal. The other shunt line is connected to the neutral wire of the AC power supply to enable the load to operate normally.

[0191] In other embodiments, step S130 includes: time-division switching of the power-on circuit where the switching circuit is located, and acquiring the rectified electrical signal when the switching circuit forms a power-on circuit through the line where the rectifier circuit is located.

[0192] Here, the switch control circuit controls the output terminal of the switch circuit to switch between the first line and the second line, so that the load and the switch circuit form corresponding energized circuits through the first line and the second line respectively in a time-sharing manner. The rectifier circuit is located on the second line and acquires an AC signal and outputs a corresponding rectified signal when the second line is in an energized circuit. To distinguish it from the rectified signal received when the switch circuit is off, the rectified signal received when the switch circuit is on is referred to as the second rectified signal.

[0193] In some examples, step S130 further includes the following steps: acquiring a second sampling signal reflecting an AC signal or a power supply signal; comparing the voltage of the second sampling signal with a reference voltage range and generating a corresponding comparison result; based on the comparison result, selecting whether the switching circuit is connected to a first line or a second line; wherein the rectifier circuit is located on the second line; and the neutral line of the AC power is located in the reference voltage range of the first line.

[0194] Here, step S130 can be implemented by the selection circuit, the second sampling circuit, and the power supply unit in the power management circuit of the switch control circuit. Using the signal transmission path provided by the circuit structure, the power supply unit receives the second rectified electrical signal within the preset reference voltage range and continuously supplies power to the power supply.

[0195] In some examples, when the comparison result indicates that the voltage of the second sampled signal does not fall within a preset reference voltage range, the switching circuit switches from connecting to the second line to connecting to the first line; conversely, it switches from connecting to the first line to connecting to the second line. Taking a full-wave rectifier circuit as an example, when the phase of the AC current falls within a preset phase range, the selection circuit immediately selects the second line based on a time-division control signal; and when the phase of the AC current exceeds the phase range, the selection circuit immediately selects the first line based on a time-division control signal.

[0196] In some other examples, the method of selecting to connect the switching circuit to the second line where the rectifier circuit is located in step S130 includes: timing based on the received comparison result, and adjusting the shunt control signal to control the selection circuit to switch from the first line to the second line when the timing reaches a timing threshold.

[0197] Taking the rectifier circuit as a full-wave rectifier circuit as an example, when the selection circuit switches to the first line, a timing is started. This timing is related to the AC power frequency cycle, power supply duration, etc., and when the timed duration reaches a timing threshold, the branch control signal is adjusted to control the selection circuit to switch from the first line to the second line.

[0198] Based on this, the method of selecting the connection of the switching circuit to the second line where the rectifier circuit is located in step S130 includes: when the timing reaches a timing threshold, according to the current phase of the AC power, delaying or immediately executing a switching operation to switch the switching circuit from connection to the first line to connection to the second line. Here, in order to maximize the utilization efficiency of the AC power's active power, the structure of the selection circuit is related to the rectifier circuit, load, etc. in this application. Here, this step can be combined with the foregoing... Figure 5 The corresponding descriptions and implementations will not be detailed here. As mentioned above... Figure 5 Taking the circuit structure shown as an example, the selection circuit initially selects the second line so that the rectifier circuit outputs a second rectified electrical signal. The power supply unit acquires the second sampled signal obtained by the second sampling circuit from the second rectified electrical signal, and detects whether the voltage of the second sampled signal falls within the reference voltage range. If so, the selection circuit continues to select the second line; otherwise, the selection circuit switches to the first line. When switching to the first line, a timer is started. When the timer exceeds the timing threshold, the switch unit M1 in the selection circuit is opened, and the phase limiting unit selects the switching time from the first line to the second line based on the phase of the AC power. When the switching time is reached, the line is switched. The power supply unit uses the second rectified electrical signal received during the conduction of the second line to provide power to the power supply, and uses the second rectified electrical signal for energy storage, so that the output of the power supply can provide stable power during at least one switching cycle of the selection circuit.

[0199] In other examples, to prevent the voltage of the rectified signal received by the power supply unit from being too high when the selection circuit switches to the second line, which could easily damage the devices in the power management circuit, the switching control method further includes the step of: detecting the voltage of the second sampling signal, and when the voltage of the second sampling signal is higher than a preset protection voltage threshold, selecting the first line where the neutral line of the AC power supply is connected to the switching circuit.

[0200] Please refer to the circuit structure of the power supply unit in the switch control circuit. Figure 19The first protection module 234 in the power supply unit is connected in parallel with the branch control module 233 and detects the voltage of the second sampled signal. Here, the first protection module 234 can directly compare the voltage of the second sampled signal with a preset protection voltage threshold, or it can perform voltage division or amplification of the second sampled signal before comparing it with the protection voltage threshold. When the voltage of the second sampled signal is higher than the preset protection voltage threshold, the selection circuit of the line where the switching circuit is located is controlled to switch from the second line to the first line. The protection voltage threshold is higher than or equal to the upper limit of the aforementioned reference voltage range.

[0201] Similar to step S120, with the stable power supply provided in step S130, the control circuit in the switch control circuit can execute step S140 during the conduction of the switch circuit.

[0202] In step S140, during the conduction of the switching circuit, the switching circuit is controlled to disconnect after receiving a control message.

[0203] Here, using the circuit modules included in the control circuit mentioned in step S120, the control circuit performs the aforementioned various control operations relying on the power supply. For example, the control circuit uses the electrical energy provided by the power supply to continuously monitor whether control information is received, so as to control the switching circuit to open. As another example, the control circuit uses the electrical energy provided by the power supply to continuously monitor whether control information is received, so as to output control signals to the pre-configured air conditioner according to the air conditioning and temperature indicated in the control information. These will not be described in detail here.

[0204] To prevent the load from starting or stopping within the peak AC voltage range, the switching control method provided in this application further includes step S150, which involves detecting the phase of the current AC signal and outputting a zero-crossing detection signal, so that the control circuit can respond to the control information with a delay. For example, the control circuit may only respond to the control information upon receiving both the control information and the zero-crossing detection signal.

[0205] To obtain a zero-crossing detection signal during the switching circuit's open period, step S150 includes detecting a first detection signal reflecting the current AC signal phase based on a zero-crossing phase interval during the switching circuit's open period, and outputting the zero-crossing detection signal. Here, some methods for zero-crossing detection of AC signals include detecting the zero-crossing phase interval of a first rectified signal output by the rectifier circuit during the switching circuit's open period. For example, the first rectified signal is sampled to obtain a first detection signal, and a corresponding zero-crossing detection signal is output by detecting whether the voltage of the first detection signal falls within the zero-crossing voltage interval corresponding to the zero-crossing phase interval. In other examples, the AC current flowing to the rectifier circuit during the switching circuit's open period is directly acquired, and a first detection signal is obtained using a rectifier bridge, sampling resistor, etc., and a corresponding zero-crossing detection signal is output by detecting whether the voltage of the first detection signal falls within the zero-crossing voltage interval corresponding to the zero-crossing phase interval.

[0206] To reduce internal losses during the switching circuit's disconnection period, step S150 employs a method of intermittently detecting the phase of the first detection signal to perform zero-crossing detection, and outputs a zero-crossing detection signal corresponding to the zero-crossing phase interval. For example... Figure 8 As shown, a switch M2 with a control terminal is installed on the line where the first detection signal is obtained. The first detection signal is obtained during the conduction period of switch M2, and a zero-crossing detection signal is output by detecting the voltage of the first detection signal. The conduction interval of switch M2 can be set according to a preset time interval or is an adjustable interval.

[0207] In some examples, when the voltage of the first detection signal is detected to be outside the reference voltage range, the switch is controlled to turn on at preset time intervals, and the voltage of the first detection signal is detected during the on period. When the voltage of the first detection signal falls into the reference voltage range, the switch M2 is controlled to remain on until the voltage of the first detection signal is detected to exceed the reference voltage range. Then, the switch M2 is controlled to turn off, and the switch is controlled to turn on at preset time intervals.

[0208] In some other examples, when the voltage of the first detection signal is detected to be outside the reference voltage range, the switch is controlled to turn on at a preset time interval, and the voltage of the first detection signal is detected during the on period. When the voltage of the first detection signal falls into the reference voltage range, at least one of the duty cycle and frequency of the switch M2 is adjusted to ensure that the voltage of the first detection signal falls further into the zero-crossing voltage range.

[0209] Here, the reference voltage range in each example covers the zero-crossing voltage range to ensure that the output has sufficient zero-crossing detection signal to be acquired by the control circuit. The method for adjusting switch M2 based on the circuit structure that performs zero-crossing detection during switch open-circuit operation can be found in the circuit structure mentioned above for the first zero-crossing detection unit, and will not be detailed here.

[0210] In some other examples, the step of periodically detecting the first detection signal includes: when the zero-crossing detection signal is detected to be valid, not generating the first detection signal and starting a sampling interval timer; when the sampling interval timer reaches a sampling interval threshold, generating and detecting the first detection signal. This step can be performed by the aforementioned zero-crossing detection signal output module, and will not be described in detail here.

[0211] During the conduction of the switching circuit, the switching control method further includes step S160, which involves detecting a second detection signal reflecting the phase of the alternating current electrical signal based on the zero-crossing phase interval, and outputting a zero-crossing detection signal. Here, the second detection signal is obtained by acquiring an alternating current or rectified electrical signal, and the zero-crossing detection signal is output by detecting whether the voltage of the second detection signal falls within the zero-crossing voltage interval.

[0212] As described above, the second rectified electrical signal is output using a phase-cutting method. Since the phase range of the second rectified electrical signal includes a zero-crossing phase range, step S160 includes: acquiring the second rectified electrical signal that includes the zero-crossing phase range and generating a second detection signal; detecting the voltage of the second detection signal based on the zero-crossing voltage range corresponding to the zero-crossing phase range, and outputting a zero-crossing detection signal according to the detection result. Figure 9 As shown, the second sampling signal is acquired using voltage divider resistors 23 and R24 to obtain the second detection signal, and the voltage of the second detection signal is detected based on the zero-crossing voltage range corresponding to the zero-crossing phase range, and the zero-crossing detection signal is output.

[0213] Correspondingly, the control circuit performs the operation of turning the switch circuit on or off by: based on the zero-crossing detection signal and after receiving a control information, controlling the switch circuit to turn on or off.

[0214] During the period when the switching circuit is off, in some examples, when the control circuit receives control information indicating that the switching circuit is on, the control circuit controls the switching circuit to be on during the period when the zero-crossing detection signal is valid. For example, the control circuit generates and maintains a logic signal valid based on the received control information, and when the zero-crossing detection signal is received, it outputs a control signal to the switching circuit to turn on using preset control logic corresponding to the two signals.

[0215] In some examples, during the disconnection of the switching circuit, when the control circuit receives control information indicating that the switching circuit should be turned on, the control circuit generates a control delay based on the zero-crossing detection signal, and controls the switching circuit to turn on when the control delay times out and the control information is received. For example, the switching circuit includes a relay. Since the relay requires a response time, the control circuit incorporates a corresponding delay timer based on the response time of the relay used. The timer starts based on the rising edge (or falling edge) of the acquired zero-crossing detection signal. The control circuit outputs a control signal indicating that the switching circuit is turned on based on the logic signal generated by the acquired control information, the zero-crossing detection signal, and the delay timeout signal, thereby ensuring that the relay avoids turning on during the peak voltage range of the AC power.

[0216] During the conduction of the switching circuit, in some examples, when the control information received by the control circuit indicates that the switching circuit should be disconnected, the control circuit controls the switching circuit to disconnect during the validity period of the zero-crossing detection signal. For example, the control circuit generates and maintains a logic signal valid based on the received control information, and when the zero-crossing detection signal is received, it outputs a disconnect control signal to the switching circuit using preset control logic corresponding to the two signals.

[0217] In some examples, during the conduction of the switching circuit, when the control circuit receives control information indicating that the switching circuit should be disconnected, the control circuit generates a control delay based on the zero-crossing detection signal, and controls the switching circuit to disconnect when the control delay times out and the control information is received. For example, the switching circuit includes a relay. Since the relay requires a response time, the control circuit has a built-in corresponding delay timer based on the response time of the relay used. The timer starts from the rising edge (or falling edge) of the acquired zero-crossing detection signal. The control circuit outputs a control signal indicating disconnection to the switching circuit based on the logic signal generated by the acquired control information, the zero-crossing detection signal, and the control logic of the delay timeout signal, thereby ensuring that the relay avoids disconnection within the peak voltage range of the AC power.

[0218] The switching control method further includes a self-powering step using the power supply and / or AC signal. Specifically, during the disconnection period of the switching circuit, a self-powering step is performed using the power supply provided by the secondary output unit. Taking the first self-powering circuit in the aforementioned switching control circuit as an example, the first self-powering circuit includes diodes and capacitors. The diodes prevent current backflow, and the capacitors filter the voltage to provide a stable self-powering supply that conforms to the operating voltage of the power management circuit. Depending on the voltage difference between the actual operating voltage of the power management circuit and the output voltage of the power supply, the first self-powering circuit may also include voltage dividers or boosters.

[0219] During the conduction period of the switching circuit, a self-powered step is performed using the power supply provided by the continuous power supply unit. Taking the second self-powered circuit in the aforementioned switch control circuit as an example, based on the voltage difference between the operating voltage of the actual power management circuit and the output voltage of the power supply, the second self-powered circuit can be a wire, or contain electrical components such as voltage dividers or boosters, and is connected between the output terminal of the power supply and the power management circuit. In summary, using the switch control circuit provided in this application, the purpose of providing internal power supply during both the disconnection and conduction periods of the switching circuit can be achieved without a separate AC circuit connection. In addition, by detecting the zero-crossing phase of the AC power during the disconnection and conduction periods of the switching circuit, and using the generated zero-crossing detection signal to delay and control the switching operation of the switching circuit, the impact of the peak voltage range of the AC power on the load is effectively reduced, and the service life of the load is extended.

[0220] It should be noted that the methods described in the steps of this application are merely examples. Based on the descriptions of the examples in the aforementioned switch control circuit, adjustments can be made according to actual circuit requirements and on the basis of each example. Other circuits that are adapted to actual circuits but do not affect the circuit function should be regarded as specific circuit examples under the technical concept provided in this application.

[0221] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this application should still be covered by the claims of this application.

Claims

1. A switch control circuit for controlling a switch circuit, said switch circuit being connected to a line circuit containing a load, characterized in that, The switch control circuit includes: A transformer circuit, connected to a rectifier circuit, is used to provide power to a power supply through the rectified electrical signal output by the rectifier circuit; wherein the transformer circuit includes a primary-side input unit and a secondary-side output unit, wherein the primary-side input unit is connected to the rectifier circuit; A power management circuit, at least connected to the primary-side input unit, is configured to acquire a first sampling signal reflecting the power supply signal output by the power supply during the switching circuit is off, and control the current flowing through the primary-side input unit based on the first sampling signal so that the power supply output by the secondary-side output unit is stable; and to continuously supply power to the power supply by means of the rectified electrical signal during the switching circuit is on. The control circuit, with the power supply support, is used to control the switching circuit to be turned on or off after receiving a control message; The rectified electrical signal received by the power management circuit includes: a second rectified electrical signal obtained by rectifying the AC current flowing through the switching circuit based on the rectifier circuit; The power management circuit includes a continuous power supply unit, which is used to continuously supply power to the power supply using the second rectified electrical signal during the conduction of the switching circuit.

2. The switch control circuit according to claim 1, characterized in that, The rectified electrical signal received by the primary-side input unit includes the first rectified electrical signal obtained by the rectifier circuit rectifying the AC power flowing to the switching circuit. The power management circuit includes a control unit electrically connected to the primary-side input unit, which is used to acquire the first sampling signal during the period when the switching circuit is off, and control the current flowing through the primary-side input unit based on the first sampling signal.

3. The switch control circuit according to claim 2, characterized in that, The control unit includes: The adjustment module is located on the line between the primary input unit and the voltage ground, and is used to control the on / off state or current change of the line between the primary input unit and the voltage ground. A control module, connected to the adjustment module, is used to control the adjustment module based on the first sampled signal.

4. The switch control circuit according to claim 3, characterized in that, The control module includes: The detection submodule is used to output a detection signal by detecting the first sampled signal; A control submodule, connected to the detection submodule, is used to control the adjustment module based on the detection signal.

5. The switch control circuit according to claim 4, characterized in that, The detection submodule includes any of the following: A comparator circuit is used to compare the voltage of the first sampled signal with a preset reference voltage and output a detection signal based on the comparison result; The differential circuit is used to generate an error signal of the voltage difference between the voltage of the first sampled signal and a preset reference voltage, and to output a detection signal based on the error signal.

6. The switch control circuit according to claim 4, characterized in that, The control submodule controls at least one of the following: current change frequency, switching frequency, on-time duration, and off-time duration of the adjustment module based on the detection signal.

7. The switch control circuit according to claim 2, characterized in that, The control unit also acquires a third sampling signal that reflects the line electrical signal in the line where the primary-side input unit is located, and controls the current flowing through the primary-side input unit based on the first sampling signal and the third sampling signal.

8. The switch control circuit according to claim 7, characterized in that, The control unit controls the line where the primary-side input unit is located to be turned on based on the first sampling signal, and controls the line where the primary-side input unit is located to be turned off based on the first sampling signal and the third sampling signal.

9. The switch control circuit according to claim 1, characterized in that, The secondary output unit includes: a secondary winding grounded by voltage, and a unidirectional conduction module connected to the output terminal of the secondary winding.

10. The switch control circuit according to claim 9, characterized in that, The unidirectional conduction module includes a diode, or the unidirectional conduction module includes a diode and a capacitor connected between the diode and ground.

11. The switch control circuit according to claim 1, characterized in that, It also includes a first self-powered circuit for supplying power to the power management circuit via the power supply during the period when the switching circuit is off.

12. The switch control circuit according to claim 11, characterized in that, The first self-powered circuit includes a diode connected to the output terminal of the secondary output unit and a capacitor connected between the diode and ground.

13. The switch control circuit according to claim 11, characterized in that, The first self-powered circuit is externally connected between the power supply pins of the secondary output unit and the power management circuit; or at least some components of the first self-powered circuit are integrated into the power management circuit.

14. The switch control circuit according to claim 2, characterized in that, Also includes: The first sampling circuit is connected between the secondary output unit and the power management circuit, and is used to sample the output side of the secondary output unit and generate a first sampling signal.

15. The switch control circuit according to claim 14, characterized in that, The first sampling circuit is integrated into the power management circuit and outputs the first sampled signal after sampling processing to the control unit.

16. The switch control circuit according to claim 1, characterized in that, It also includes a selection circuit on the AC line on one side of the output terminal of the switching circuit, used to select whether to connect the switching circuit to the first line or the second line during the conduction of the switching circuit, so as to form a corresponding power-on circuit respectively. The power supply unit is used to convert the acquired second rectified electrical signal into a power supply signal when the selection circuit switches to the second line, so as to continuously provide power to the power supply.

17. The switch control circuit according to claim 16, characterized in that, It also includes a second sampling circuit for sampling the electrical signal reflecting the AC signal in the second line or sampling the power supply signal of the power supply, so as to generate a second sampling signal and output it to the power supply unit; correspondingly, the power supply unit includes: The branch control module is connected to the selection circuit and is used to output a branch control signal to the selection circuit by detecting the second sampling signal, so as to control the selection circuit to switch between the first line and the second line. The output module is connected to the rectifier circuit and is used to continuously supply power to the power supply based on the received second rectified electrical signal.

18. The switch control circuit according to claim 17, characterized in that, The branch control module includes: The comparator circuit is used to compare the voltage of the second sampled signal with the reference voltage range and generate the corresponding comparison result; A control subcircuit, connected to the comparison subcircuit, is used to output the branch control signal based on the comparison result to control the selection circuit to switch from the second line to the first line.

19. The switch control circuit according to claim 18, characterized in that, The control sub-circuit includes: a timer for timing based on the received comparison result, and adjusting the branch control signal to control the selection circuit to switch from the first line to the second line when the timing reaches a timing threshold.

20. The switch control circuit according to claim 19, characterized in that, The timing threshold is a fixed time threshold, or it is set according to the duration for which the selection circuit selects the first line within at least one switching cycle.

21. The switch control circuit according to claim 18, characterized in that, The reference voltage range includes the zero-crossing voltage range.

22. The switch control circuit according to claim 16, characterized in that, The selection circuit includes: A switching unit, disposed on the AC power line, is used to controllably turn on or off based on a received branch control signal, so as to respond at least immediately to a switching operation that switches the switching circuit from access to the second line to access to the first line.

23. The switch control circuit according to claim 22, characterized in that, The selection circuit further includes a phase limiting unit, which, when the switching unit is disconnected, performs a switching operation that delays or immediately switches the switching circuit from accessing the first line to accessing the second line, based on the current phase of the alternating current.

24. The switch control circuit according to claim 17, characterized in that, The power supply unit further includes a first protection module, used to detect the voltage of the second sampling signal, and when the voltage of the second sampling signal is higher than a preset protection voltage threshold, control the selection circuit to switch from the second line to the first line.

25. The switch control circuit according to claim 17, characterized in that, The power supply unit further includes a second protection module for providing overcurrent protection for the power supply.

26. The switch control circuit according to claim 1, characterized in that, Also includes: A second self-powered circuit is used to supply power to the power management circuit during the conduction of the switching circuit.

27. The switch control circuit according to claim 1, characterized in that, Also includes: The zero-crossing detection circuit is used to detect the phase of the current AC signal based on the zero-crossing phase interval and output a zero-crossing detection signal to the control circuit. The control circuit controls the switching circuit to turn on or off based on the zero-crossing detection signal and upon receiving control information.

28. The switch control circuit according to claim 27, characterized in that, The zero-crossing detection circuit includes: The first zero-crossing detection unit is used to detect whether a first detection signal reflecting the current AC phase falls into the zero-crossing phase interval during the period when the switching circuit is open, and outputs the zero-crossing detection signal.

29. The switch control circuit according to claim 28, characterized in that, The first zero-crossing detection unit obtains a first detection signal by acquiring the rectified AC signal, detects whether the first detection signal falls into the zero-crossing phase interval, and outputs the zero-crossing detection signal.

30. The switch control circuit according to claim 28, characterized in that, The first zero-crossing detection unit detects the phase of the first detection signal at intervals, and outputs a zero-crossing detection signal based on the phase of the first detection signal and the detection results within the zero-crossing phase interval.

31. The switch control circuit according to claim 30, characterized in that, The first zero-crossing detection unit includes: The first detection signal generation module generates a first detection signal corresponding to the current AC phase at intervals; wherein the first detection signal reflects at least the AC signal within the zero-crossing phase interval. The first zero-crossing detection module is connected to the first detection signal generation module and is used to detect the voltage of the first detection signal based on the zero-crossing voltage range corresponding to the zero-crossing phase range, and output the zero-crossing detection signal based on the detection result.

32. The switch control circuit according to claim 31, characterized in that, The first detection signal generation module includes: A sampling submodule including a switch is used to perform a data acquisition operation and output the first detection signal during the on-time of the switch. The control submodule is connected to the control terminal of the switch and is used to output a sampling control signal by detecting the first detection signal or the zero-crossing detection signal to control the switch.

33. The switch control circuit according to claim 32, characterized in that, When the voltage of the first detection signal is detected to fall into a preset reference voltage range, the control submodule controls the sampling control signal to remain effective within the reference voltage range, or adjusts at least one of the duty cycle and frequency of the sampling control signal, so that the first zero-crossing detection module detects whether the voltage of the first detection signal falls into the zero-crossing voltage range corresponding to the zero-crossing phase range; wherein, the reference voltage range covers the zero-crossing voltage range corresponding to the zero-crossing phase range.

34. The switch control circuit according to claim 33, characterized in that, When the voltage of the first detection signal is detected to be outside the preset reference voltage range, the control submodule detects the voltage of the output first detection signal and outputs a sampling control signal at a preset interval.

35. The switch control circuit according to claim 32, characterized in that, When the zero-crossing detection signal is detected to be valid, the control submodule outputs the sampling control signal to control the switch to open and starts a sampling interval timer; when the sampling interval timer reaches a sampling interval threshold, the control submodule adjusts the sampling control signal to control the switch to turn on.

36. The switch control circuit according to claim 27, characterized in that, The zero-crossing detection circuit includes: The second zero-crossing detection unit is used to detect whether the second detection signal, which reflects the current AC phase, falls into the zero-crossing phase interval during the conduction of the switching circuit, and outputs the zero-crossing detection signal.

37. The switch control circuit according to claim 36, characterized in that, The second zero-crossing detection unit includes: The second detection signal generation module generates a second detection signal that reflects the current AC phase. The second zero-crossing detection module is connected to the second detection signal generation module. It is used to detect the voltage of the second detection signal based on the zero-crossing voltage range corresponding to the zero-crossing phase range, and output the zero-crossing detection signal based on the detection result.

38. The switch control circuit according to claim 37, characterized in that, The second detection signal generation module is also used to acquire the rectified electrical signal input to the power management circuit during the conduction of the switching circuit to output the second detection signal.

39. The switch control circuit according to any one of claims 27-38, characterized in that, After receiving a control message, the control circuit controls the switching circuit to turn on or off during the valid period of the zero-crossing detection signal; or, the control circuit generates a control delay based on the zero-crossing detection signal, and controls the switching circuit to turn on or off when the control delay expires and the control message is received.

40. The switch control circuit according to claim 27, characterized in that, The zero-crossing detection circuit includes a zero-crossing detection signal output module, used to amplify and output the generated zero-crossing detection signal; wherein the amplification process includes amplification based on voltage amplitude and / or amplification based on effective duration.

41. The switch control circuit according to claim 40, characterized in that, The zero-crossing detection signal output module converts the zero-crossing detection signal with an effective pulse width generated inside the zero-crossing detection circuit into a zero-crossing detection signal with a preset duration and outputs it; wherein the duration of the effective pulse width is less than the preset duration.

42. The switch control circuit according to claim 1, characterized in that, The control circuit includes: An interaction unit is used to acquire control information; The processing unit, connected to the interaction unit, is used to control at least the switching circuit to be turned on or off based on the control information.

43. The switch control circuit according to claim 1, characterized in that, Also includes: A startup power supply circuit is used to provide startup power to the power management circuit.

44. A smart switch, characterized in that, The smart switch, used for connecting to an AC power line containing a load, includes: A switching circuit is connected to the AC power line and is controlled to be turned on or off; A rectifier circuit is used to rectify the connected AC power and output a rectified signal during the off-state and on-state periods of the switching circuit, respectively. The switch control circuit as described in any one of claims 1-42 is connected to the rectifier circuit and controls the switch circuit.

45. The intelligent switch according to claim 44, characterized in that, The rectifier circuit includes at least one of the following: The first rectifier unit is connected to the AC power line connected to the input terminal of the switching circuit, and is used to rectify the AC power flowing to the switching circuit and output a first rectified signal; wherein, the first rectified signal is a rectified signal provided by the rectifier circuit. The second rectifier unit is connected to the AC power line connected to the output terminal of the switching circuit, and is used to rectify the AC power and output a second rectified signal; wherein the second rectified signal is another rectified signal provided by the rectifier circuit.

46. ​​The intelligent switch according to claim 45, characterized in that, The rectifier circuit includes a first rectifier unit and a second rectifier unit; wherein the first rectifier unit provides a first rectified electrical signal when the switching circuit is off, and the second rectifier unit provides a second rectified electrical signal when the switching circuit is on.

47. The intelligent switch according to claim 46, characterized in that, Both the first rectifier unit and the second rectifier unit include a rectifier bridge and a filter capacitor; wherein, the forward voltage of the rectifier bridge in the first rectifier unit is higher than the forward voltage of the rectifier bridge in the second rectifier unit.

48. The intelligent switch according to claim 47, characterized in that, The switching circuit includes a relay; the relay operates by means of power from the power supply.

49. A switch control method for controlling a switch circuit, wherein the switch circuit and a load are connected to an AC power line, characterized in that... The switch control method includes: During the period when the switching circuit is open, a first sampling signal is acquired to reflect the power supply provided by the secondary output unit of a transformer circuit, and the connection or current change of the line where the primary input unit of the transformer circuit is located is controlled based on the first sampling signal; wherein, the transformer circuit provides power to the power supply through a rectified signal provided by a rectifier circuit, and the rectified signal includes a second rectified signal obtained by rectifying the AC current flowing through the switching circuit based on the rectifier circuit; During the conduction of the switching circuit, power is continuously supplied to the power supply via the received rectified electrical signal; With the support of the power supply, a control circuit controls the switching circuit to turn on or off after receiving a control message.

50. The switching control method according to claim 49, characterized in that, The step of controlling the on / off state or current change of the line where the primary-side input unit is located based on the first sampling signal includes any one of the following: The voltage of the first sampled signal is compared with a preset reference voltage, and the on / off state or current change of the line where the primary input unit is located is controlled based on the comparison result; Based on the error between the voltage of the first sampled signal and the preset reference voltage, the on / off state or current change of the line where the primary input unit is located is controlled.

51. The switching control method according to claim 50, characterized in that, The steps of controlling the on / off state or current change of the line where the primary input unit is located include: controlling at least one of the following: current change frequency, on / off frequency, on-time duration, and off-time duration of the line where the primary input unit is located.

52. The switching control method according to claim 51, characterized in that, The step of controlling the on / off state or current change of the line where the primary-side input unit is located based on the first sampling signal includes: Acquire a third sampling signal that reflects the line electrical signal in the line where the primary-side input unit is located; The current flowing through the primary-side input unit is controlled based on the first and third sampling signals.

53. The switching control method according to claim 52, characterized in that, The step of controlling the current flowing through the primary-side input unit based on the first sampling signal and the third sampling signal includes: controlling the line where the primary-side input unit is located to be turned on based on the first sampling signal, and controlling the line where the primary-side input unit is located to be turned off based on the first sampling signal and the third sampling signal.

54. The switching control method according to claim 49, characterized in that, The step of supplying power to the power supply via rectified electrical signal includes: The power supply circuit of the switching circuit is switched in a time-division manner, and when the switching circuit forms a power supply circuit through the line where the rectifier circuit is located, the rectified electrical signal is obtained so as to provide power to the power supply through the rectified electrical signal.

55. The switching control method according to claim 54, characterized in that, The steps for time-sharing the power circuit of the switching circuit include: Acquire a second sampling signal that reflects the AC signal or the power supply signal; The voltage of the second sampled signal is compared with a preset reference voltage range, and a corresponding comparison result is generated; Based on the comparison results, the switching circuit is selected to be connected to either the first line or the second line; wherein the rectifier circuit is located on the second line; and the neutral wire of the AC power is located on the first line.

56. The switching control method according to claim 55, characterized in that, The steps of selecting the second line where the switching circuit is connected to the rectifier circuit include: Based on the comparison results, the switching circuit is switched from accessing the first line to accessing the second line.

57. The switching control method according to claim 55, characterized in that, The steps of connecting the selection switch circuit to the first line or the second line include: outputting a branch control signal based on the comparison result, timing based on the received comparison result, and adjusting the branch control signal when the timing reaches a timing threshold to control the selection circuit to switch from the first line to the second line.

58. The switching control method according to claim 57, characterized in that, The step of selecting whether the switching circuit is connected to the first line or the second line includes: when the timing reaches a timing threshold, depending on the phase of the current AC power, delaying or immediately performing a switching operation to switch the switching circuit from being connected to the first line to being connected to the second line.

59. The switching control method according to claim 53, characterized in that, Also includes: The steps for detecting the phase of the current AC signal and outputting a zero-crossing detection signal; The step of the control circuit controlling the switching circuit to turn on or off after receiving a control information includes: controlling the switching circuit to turn on or off based on the zero-crossing detection signal and after receiving a control information.

60. The switching control method according to claim 59, characterized in that, The step of detecting the phase of the current AC signal and outputting a zero-crossing detection signal includes: During the period when the switching circuit is open, a first detection signal reflecting the phase of the current AC signal is detected based on the zero-crossing phase interval, and a zero-crossing detection signal is output. During the conduction of the switching circuit, a second detection signal reflecting the received AC signal is detected based on the zero-crossing phase interval, and a zero-crossing detection signal is output.

61. The switching control method according to claim 60, characterized in that, The step of detecting a first detection signal reflecting the current AC signal based on a zero-crossing phase interval during the switching circuit being disconnected, and outputting a zero-crossing detection signal, includes: detecting the first detection signal at intervals and outputting a zero-crossing detection signal corresponding to the zero-crossing phase interval.

62. The switching control method according to claim 61, characterized in that, The step of periodically detecting the first detection signal and outputting the zero-crossing detection signal corresponding to the zero-crossing phase interval includes: When the voltage of the first detection signal is detected to fall into a preset reference voltage range, the first detection signal is continuously acquired within the reference voltage range, or at least one of the duty cycle and frequency of the sampling control signal used to acquire the first detection signal is adjusted to detect whether the voltage of the first detection signal falls into the zero-crossing voltage range corresponding to the zero-crossing phase range; wherein, the reference voltage range covers the zero-crossing voltage range corresponding to the zero-crossing phase range.

63. The switching control method according to claim 62, characterized in that, The step of periodically detecting the first detection signal and outputting the zero-crossing detection signal corresponding to the zero-crossing phase interval includes: When the voltage of the first detection signal is detected to be outside the preset reference voltage range, the first detection signal is detected at a preset time interval.

64. The switching control method according to claim 61, characterized in that, The step of periodically detecting the first detection signal includes: when the zero-crossing detection signal is detected to be valid, not generating the first detection signal and starting a sampling interval timer; when the sampling interval timer reaches a sampling interval threshold, generating and detecting the first detection signal.

65. The switching control method according to claim 63, characterized in that, The step of detecting a second detection signal based on a zero-crossing phase interval to reflect the received AC signal and outputting a zero-crossing detection signal includes: During the conduction of the switching circuit, an electrical signal reflecting the AC signal, including the zero-crossing phase interval, is acquired, and a second detection signal is generated; Based on the zero-crossing phase interval corresponding to the zero-crossing voltage interval, the voltage of the second detection signal is detected, and the zero-crossing detection signal is output according to the detection result.

66. The switching control method according to claim 59, characterized in that, It also includes the step of amplifying and outputting the generated zero-crossing detection signal; wherein the amplification process includes amplification based on voltage amplitude and / or amplification based on effective duration.

67. The switching control method according to claim 49, characterized in that, It also includes a step of self-powering using the power supply and / or AC signal.

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