Power taking circuit of intelligent single-live-wire switch

Abstract

The utility model discloses a power taking circuit of an intelligent single-live-wire switch, which comprises a load and a power supply circuit which are connected in series, and further comprises a load power detection circuit, an auxiliary power supply circuit and an MCU (Microprogrammed Control Unit) microcontroller, the input end of the load power detection circuit is connected with the load and the power supply circuit, and the output end of the load power detection circuit is connected with the input pin of the MCU; the output end of the MCU is connected with the input end of the auxiliary power supply circuit, and the auxiliary power supply circuit is connected with the power supply circuit in parallel and connected with the output end of the MCU. A load power detection circuit and an auxiliary power supply circuit are additionally arranged in a power taking circuit of the single-live-wire switch, so that whether the single-live-wire switch is in an application scene with small load power or not is detected. If the single-live-wire switch is in a small load power application scene, the auxiliary power supply circuit is adopted for auxiliary power supply, and it is ensured that internal circuits, especially key assemblies such as a microcontroller (MCU) and a wireless communication module, of the single-live-wire switch can work normally.

Description

Technical Field

[0001] The utility model belongs to the technical field of intelligent home furnishing, and in particular relates to a power taking circuit of an intelligent single-fire switch. Background Art

[0002] A smart single-fire switch is a smart home device that is usually used to control the switch of lighting or electrical appliances. It has functions such as remote control, timing control, and voice control, and can be operated through smartphone applications or smart voice assistants. Smart single-fire switches can usually access home wireless networks and connect to smart home systems through Bluetooth or other communication protocols, allowing users to remotely control and monitor connected electrical appliances, improve the level of home intelligence, and enhance convenience and comfort in life.

[0003] Usually, in the design of an intelligent single-fire switch, the power supply circuit is a circuit that provides electrical energy to the switch. The switch needs to continuously draw power from the power supply circuit to power its internal components, such as wireless communication modules, processors, etc., to maintain the intelligent functions of the switch, such as remote control, status feedback, etc.

[0004] However, when the smart single-fire switch is in an application scenario with small load power, due to the small load power and large load resistance, the current passing through the load will decrease. Therefore, the energy flowing through the power-taking circuit will also decrease accordingly, which directly affects the energy conversion and storage efficiency of the power-taking circuit.

[0005] At the same time, the power circuit design of the smart switch has a minimum operating current requirement to ensure that its internal circuits, especially key components such as the microcontroller (MCU) and wireless communication module, can work properly. If the current passing through is lower than the minimum value due to the load power being too small, the power circuit will not be able to effectively provide enough power for these components, and may even cause the main control module of the smart switch to lose connection, and the user will not be able to control the smart switch through the network or remotely. Utility Model Content

[0006] The utility model provides a power supply circuit for an intelligent single-fire switch in an embodiment to solve the problem in the prior art that the current passing through the power supply circuit is lower than the minimum value due to the load power being too small, so that the power supply circuit cannot provide sufficient power, and even causes the main control module of the intelligent switch to lose connection, and the user cannot control the intelligent switch through the network or remotely.

[0007] In order to solve the above technical problems, the present utility model discloses the following technical solutions:

[0008] One aspect of the utility model provides a power supply circuit of an intelligent single-fire switch, wherein the power supply circuit comprises a load and a power supply circuit connected in series, and the power supply circuit further comprises a load power detection circuit, an auxiliary power supply circuit and an MCU microcontroller, wherein:

[0009] The input end of the load power detection circuit is connected to the load and the power supply circuit, and the output end is connected to the input pin of the MCU, and is configured to detect the circuit parameters of the load and send them to the MCU, wherein the circuit parameters include: current and / or voltage;

[0010] The output end of the MCU is connected to the input end of the auxiliary power supply circuit, and is configured to calculate the power value of the load according to the received circuit parameters of the load, and generate an auxiliary power supply signal and send it to the auxiliary power supply circuit when the load power value is less than a preset threshold;

[0011] The auxiliary power supply circuit is connected in parallel with the power supply circuit and connected to the output end of the MCU, and is configured to provide electric energy to the power supply circuit when an auxiliary power supply signal is received.

[0012] Optionally, the auxiliary power supply circuit includes a power switch and a DCDC converter, wherein the power switch is arranged between the DCDC converter and the power supply circuit, and the control end of the power switch is connected to the output end of the MCU, and is configured to close when an auxiliary power supply signal is received, so that the power supply circuit receives the electric energy transmitted by the auxiliary power supply circuit through the DCDC converter; the DCDC converter is configured to convert the electric energy into the voltage and current required by the power supply circuit.

[0013] Optionally, the load power detection circuit includes a voltage divider connected to the load and the power supply circuit, the power point of the voltage divider is connected to the load, the voltage dividing point of the voltage divider is connected to the input pin of the MCU, and is arranged between two voltage dividing resistors R2 and R3, one of which is connected to the power point, and the other is connected to the common ground or reference potential of the power supply circuit; the voltage divider is configured to detect the voltage of the load;

[0014] The load power detection circuit also includes a shunt resistor R1 connected in series with the load and configured to detect the current value at the load;

[0015] The load power detection circuit also includes a bidirectional TVB diode configured to provide overvoltage protection for the load power detection circuit.

[0016] Optionally, the auxiliary power supply circuit further includes a bridge rectifier configured to convert alternating current into direct current;

[0017] The auxiliary power supply circuit also includes a filter capacitor, which is arranged in the bridge rectifier output circuit and is configured to smooth the voltage output by the bridge rectifier;

[0018] The DCDC converter is configured to convert the voltage output by the filter capacitor into a voltage required by the MCU and other circuits.

[0019] Optionally, an input pin of the MCU is connected to the load power detection circuit, and an output pin is connected to the control end of the power switch;

[0020] The MCU includes an analog-to-digital converter ADC, which is configured to obtain the current and voltage measured by the load power detection circuit through an input pin and convert them into digital values ​​to obtain the circuit parameters of the load;

[0021] The MCU also includes a power judgment module connected to the ADC, which is configured to calculate the power value of the load based on the converted voltage and current values, and compare the load power value with a preset threshold value. When the load power value is less than the preset threshold value, an auxiliary power supply signal is generated and sent to the control end of the power switch through the output pin.

[0022] Optionally, the load power detection circuit also includes a low-pass filter composed of a resistor and a capacitor; the low-pass filter is arranged between the voltage divider, the shunt resistor and the MCU, and is configured to filter high-frequency noise and allow low-frequency signals to pass.

[0023] Optionally, the load power detection circuit also includes an operational amplifier; the input end of the operational amplifier is connected to the output end of the voltage divider and the shunt resistor, and the output end is connected to the input end of the low-pass filter, and is configured to amplify the signal to a range recognizable by the MCU.

[0024] Optionally, the load power detection circuit further includes an isolation device; the isolation device is disposed between the operational amplifier and the MCU, and is configured to separate the signal source and the MCU to prevent high voltage or fault from being transmitted to sensitive circuits in the MCU.

[0025] Optionally, the auxiliary power supply circuit also includes a voltage stabilizer; the voltage stabilizer is connected to the output end of the DCDC converter and is configured to stabilize the voltage flowing out of the DCDC converter.

[0026] Optionally, the power switch is a MOSFET field effect transistor.

[0027] The power supply circuit of an intelligent single-fire switch of the embodiment of the utility model detects whether the single-fire switch is in a small load power application scenario by adding a load power detection circuit and an auxiliary power supply circuit in the power supply circuit of the single-fire switch. If the single-fire switch is in a small load power application scenario, the auxiliary power supply circuit is used for auxiliary power supply to ensure that its internal circuits, especially key components such as the microcontroller (MCU) and the wireless communication module, can work normally. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram of the structure of a power supply circuit of an intelligent single fire switch provided in an embodiment of the utility model;

[0029] Figure 2 A schematic structural diagram of a power supply circuit of another intelligent single fire switch provided in an embodiment of the utility model. DETAILED DESCRIPTION

[0030] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0031] Figure 1 Schematic diagram of a power supply circuit of an intelligent single-fire switch disclosed in an embodiment of the utility model. In the embodiment disclosed in the utility model, the power supply circuit includes a load 1 and a power supply circuit 2 connected in series. Figure 1 As shown, the power supply circuit also includes a load power detection circuit 3, an auxiliary power supply circuit 4 and a microcontroller MCU5.

[0032] The input end of the load power detection circuit 3 is connected to the load 1 and the power supply circuit 2, and the output end is connected to the input pin of the MCU 5. The load power detection circuit 3 is connected in series with the load 1 and is configured to detect circuit parameters at the load 1 and send them to the MCU 5. The circuit parameters include: current and / or voltage.

[0033] like Figure 2 As shown, the load power detection circuit 3 includes a voltage divider connected to the load 1 and the power supply circuit 2, the power supply point (v1 in the figure) of the voltage divider is connected to the load 1, and the voltage dividing point (v2 in the figure) of the voltage divider is connected to the input pin of the MCU5, and is arranged between two voltage dividing resistors R2 and R3, one of which is connected to the power supply point, and the other is connected to the common ground or reference potential of the power supply circuit 2, and the voltage divider is configured to detect the voltage of the load 1.

[0034] Since the analog-to-digital converter ADC of MCU5 usually has a maximum voltage limit

[0035] (such as 3.3V or 5V), and the voltage across load 1 may be higher than this limit, so a voltage divider is set to reduce the voltage value delivered to the MCU5 input pin so that MCU5 can safely measure the reduced voltage without causing damage.

[0036] like Figure 2 As shown, the load power detection circuit 3 also includes a shunt resistor R1 connected in series with the load 1, and is configured to detect the current value at the load 1. When the load 1 is working, the current flows through the shunt resistor R1. Since the resistance value of R1 is known, the current passing through it will generate a voltage drop at both ends thereof that is proportional to the current magnitude.

[0037] The load power detection circuit 3 also includes a bidirectional TVB diode D8, which is configured to provide overvoltage protection for the load power detection circuit 3. A diode is a semiconductor device used to protect electronic circuits from voltage spikes. It is used to quickly conduct current above a specific threshold voltage (called a "breakdown voltage") to protect other components in the circuit. A bidirectional TVS diode can respond to forward and reverse voltage spikes and is an ideal overvoltage protection device.

[0038] The TVS diode is integrated into the load power detection circuit 3 and connected to the input terminal of the circuit and the ground. It does not affect the circuit behavior under normal working conditions, but once an overvoltage is detected, the TVS diode immediately operates to shunt the potentially dangerous high voltage to the ground line, thereby ensuring the continued reliable operation of the load power detection circuit 3 under unstable power supply or other abnormal conditions.

[0039] The output end of MCU5 is connected to the input end of the auxiliary power supply circuit 4, and is configured to calculate the power value of load 1 based on the received load 1 current and load 1 voltage, and generate an auxiliary power supply signal and send it to the auxiliary power supply circuit 4 when the load 1 power value is less than a preset threshold.

[0040] In one embodiment disclosed in the present utility model, the load power detection circuit 3 further includes a low-pass filter composed of a resistor and a capacitor. The low-pass filter is arranged between the voltage divider, the shunt resistor and the MCU5, and is configured to filter high-frequency noise and pass low-frequency signals. It can reduce rapid changes and spikes of the signal and smooth the signal.

[0041] In one embodiment disclosed in the utility model, the load power detection circuit 3 also includes an operational amplifier. The input end of the operational amplifier is connected to the output end of the voltage divider and the shunt resistor, and the output end is connected to the input end of the low-pass filter, and is configured to amplify the signal to a range recognizable by the MCU5. The operational amplifier can amplify weak signals and increase their level to a range acceptable to the ADC in the MCU5. The operational amplifier can also be used as a buffer to isolate different parts of the circuit and reduce the impact of impedance.

[0042] In one embodiment disclosed in the present utility model, the load power detection circuit 3 further includes an isolation device, which may be an optical coupler or a magnetic isolation device. The isolation device is disposed between the operational amplifier and the MCU5 and is configured to separate the signal source from the MCU5 to prevent high voltage or fault from being transmitted to sensitive circuits in the MCU5.

[0043] In the embodiment disclosed in the present utility model, the MCU5 at least includes a central processing unit CPU, a memory, an input / output interface I / O, a communication interface and an analog-to-digital converter ADC.

[0044] in,

[0045] The central processing unit (CPU) is the brain of the MCU5 and is responsible for executing program instructions and handling logic and computing tasks.

[0046] Memory can include random access memory RAM, and read-only memory ROM or flash memory. Random access memory is used to store temporary data and variables when the program is running; read-only memory ROM or flash memory is used to store firmware and program code, which is usually written only once or can be programmed multiple times during the life cycle of the device.

[0047] The input / output interface I / O includes a GPIO (general purpose input and output) port for connecting external devices such as buttons, touch panels, LED indicators, etc. In the disclosed embodiment of the utility model, an input pin of the MCU5 is connected to the load power detection circuit 3, and an output pin is connected to the control end of the auxiliary power supply circuit 4.

[0048] The communication interface may include UART, I2C or SPI for communication between MCU5 and other devices or modules, and may also include wireless communication modules such as Wi-Fi, Bluetooth, ZigBee, etc., so as to be integrated with the smart home system.

[0049] The analog-to-digital converter ADC is used to read analog signals, and is used to obtain the current and voltage at the load 1 measured by the load power detection circuit 3 through the input pin and convert them into digital values.

[0050] The ADC receives the analog voltage signal from the voltage divider's divider point and converts it into a digital value that can be processed by the MCU 5. This conversion process allows the MCU 5 to accurately read and analyze the voltage on the load in digital form.

[0051] The ADC of MCU5 is connected to the two ends of the shunt resistor R1 to measure the voltage drop across R1. In order to improve the measurement accuracy, the resistance value of R1 is usually selected to be relatively small so that the voltage drop is within the measurable range of the ADC and does not have a significant impact on the normal operation of the circuit. Once the voltage value across R1 is obtained, MCU5 can use Ohm's law to calculate the current value.

[0052] The digitized current value and voltage value can be used to calculate the power of load 1, monitor the voltage level, or perform other tasks that require changes in the voltage of load 1.

[0053] MCU5 also includes a power judgment module connected to the ADC, which is configured to calculate the power value of load 1 based on the converted voltage and current values, and compare the power value of load 1 with a preset threshold value. When the power value of load 1 is less than the preset threshold value, an auxiliary power supply signal is generated and sent to the control end of the auxiliary power supply circuit 4 through the output pin.

[0054] like Figure 1 As shown, the auxiliary power supply circuit 4 is connected in parallel with the power supply circuit 2, and includes a power switch 42 and a DCDC converter 41. The power switch 42 can be a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), which is a transistor used to amplify or switch electronic signals.

[0055] The control terminal (gate) of MOSFET has almost no current flowing into the source and drain circuits, and will not significantly load the previous circuit. In addition, MOSFET can switch quickly, and the impedance in the on (conducting) state is very low. Under appropriate driving, it can achieve high-efficiency switching operation.

[0056] The power switch 42 is arranged between the DCDC converter 41 and the power supply circuit 2, and the control end of the power switch 42 is connected to the output end of the MCU5. It is configured to be closed when an auxiliary power supply signal is received, so that the power supply circuit 2 and the DCDC converter 41 are connected, so that the electric energy of the auxiliary power supply circuit 4 flows to the power supply circuit 2 through the DCDC converter 41, so that the power supply circuit 2 can supply power to the MCU5.

[0057] In the embodiment disclosed in the utility model, the power of the auxiliary power supply circuit 4 comes from the main power supply 6, the battery, etc. Starting the auxiliary power supply circuit 4 when needed can ensure that the intelligent switch can work normally under low power load conditions.

[0058] The DCDC converter 41 is used to convert electrical energy into the voltage, current or frequency required by the power supply circuit 2. For example, the DCDC converter 41 can increase or decrease the input voltage to a level suitable for the power supply circuit 2, and can also ensure that the output current meets the requirements of the power supply circuit 2, ensure that the power supply circuit 2 obtains the required power, and provide a stable power supply under various working conditions.

[0059] The auxiliary power supply circuit 4 further includes a bridge rectifier, which is composed of four diodes to form a bridge structure and is configured to convert the alternating current provided by the auxiliary power supply circuit 4 into direct current.

[0060] The auxiliary power supply circuit 4 also includes a filter capacitor configured to smooth the voltage output by the bridge rectifier; the filter capacitor is arranged in the output circuit of the bridge rectifier to smooth the DC voltage output by the rectifier. Since the DC power output by the bridge rectifier may contain some pulsation or fluctuation, the filter capacitor smoothes these fluctuations by storing charges, making the output DC voltage more stable.

[0061] The DCDC converter 41 is configured to convert the voltage output by the filter capacitor into a voltage required by the MCU 5 and other circuits.

[0062] In one embodiment disclosed in the present utility model, the auxiliary power supply circuit 4 further includes a voltage stabilizer. The voltage stabilizer is connected to the output end of the DCDC converter 41 and is configured to stabilize the voltage flowing out of the DCDC converter 41. The voltage stabilizer can maintain a constant output voltage and is not affected by input voltage fluctuations or output load changes.

[0063] In the present invention, a linear regulator (such as LDO) can be used, which is suitable for low-power applications and has the characteristics of simplicity and low noise.

[0064] The following is a specific example for explanation:

[0065] In a 220v loop, the load (for example, a 3w LAMP lamp) is connected in series with the power supply circuit. When the power supply circuit needs to provide more current, the current flowing through the lamp will increase, resulting in an increased probability of ghost lights. At this time, adding an auxiliary power supply circuit to the power supply circuit can reduce the total current of the power supply circuit, thereby reducing the power obtained by the lamp, which can effectively reduce the probability of ghost lights.

[0066] At the same time, the extra power obtained from the auxiliary power supply circuit can also be converted into power supply energy and provided to the power supply circuit. For example, when a low-power load is detected, the auxiliary power supply circuit is turned on and an additional 2w auxiliary power supply circuit is added. At this time, the auxiliary power supply circuit is equivalent to another load, which reduces the total current of the power supply circuit. In addition, 60-70% of the energy in the newly added auxiliary power supply circuit can be converted into usable electric energy and provided to the power supply circuit, that is, about 1.2-1.4w of electric energy can be provided to the power supply circuit.

[0067] It is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A power supply circuit for an intelligent single-fire switch, the power supply circuit comprising a load and a power supply circuit connected in series, characterized in that: The power supply circuit also includes a load power detection circuit, an auxiliary power supply circuit and an MCU microcontroller, wherein: The input end of the load power detection circuit is connected to the load and the power supply circuit, and the output end is connected to the input pin of the MCU, and is configured to detect the circuit parameters of the load and send them to the MCU, wherein the circuit parameters include: current and / or voltage; The output end of the MCU is connected to the input end of the auxiliary power supply circuit, and is configured to calculate the power value of the load according to the received circuit parameters of the load, and generate an auxiliary power supply signal and send it to the auxiliary power supply circuit when the load power value is less than a preset threshold; The auxiliary power supply circuit is connected in parallel with the power supply circuit and connected to the output end of the MCU, and is configured to provide electric energy to the power supply circuit when an auxiliary power supply signal is received.

2. The power taking circuit according to claim 1, characterized in that: The auxiliary power supply circuit includes a power switch and a DCDC converter, wherein the power switch is arranged between the DCDC converter and the power supply circuit, and the control end of the power switch is connected to the output end of the MCU, and is configured to be closed when an auxiliary power supply signal is received, so that the power supply circuit receives the electric energy transmitted by the auxiliary power supply circuit through the DCDC converter; the DCDC converter is configured to convert the electric energy into the voltage and current required by the power supply circuit.

3. The power taking circuit according to claim 1, characterized in that: The load power detection circuit includes a voltage divider connected to the load and the power supply circuit, the power point of the voltage divider is connected to the load, the voltage dividing point of the voltage divider is connected to the input pin of the MCU, and is arranged between two voltage dividing resistors R2 and R3, one of which is connected to the power point, and the other is connected to the common ground or reference potential of the power supply circuit; the voltage divider is configured to detect the voltage of the load; The load power detection circuit also includes a shunt resistor R1 connected in series with the load and configured to detect the current value at the load; The load power detection circuit also includes a bidirectional TVB diode configured to provide overvoltage protection for the load power detection circuit.

4. The power taking circuit according to claim 2, characterized in that: The auxiliary power supply circuit also includes a bridge rectifier configured to convert alternating current into direct current; The auxiliary power supply circuit also includes a filter capacitor, which is arranged in the bridge rectifier output circuit and is configured to smooth the voltage output by the bridge rectifier; The DCDC converter is configured to convert the voltage output by the filter capacitor into a voltage required by the MCU and other circuits.

5. The power taking circuit according to claim 2, characterized in that: An input pin of the MCU is connected to the load power detection circuit, and an output pin is connected to the control end of the power switch; The MCU includes an analog-to-digital converter ADC, which is configured to obtain the current and voltage measured by the load power detection circuit through an input pin and convert them into digital values ​​to obtain the circuit parameters of the load; The MCU also includes a power judgment module connected to the ADC, which is configured to calculate the power value of the load based on the converted voltage and current values, and compare the load power value with a preset threshold value. When the load power value is less than the preset threshold value, an auxiliary power supply signal is generated and sent to the control end of the power switch through the output pin.

6. The power taking circuit according to claim 3, characterized in that: The load power detection circuit also includes a low-pass filter composed of a resistor and a capacitor; the low-pass filter is arranged between the voltage divider, the shunt resistor and the MCU, and is configured to filter high-frequency noise and allow low-frequency signals to pass.

7. The power taking circuit according to claim 6, characterized in that: The load power detection circuit also includes an operational amplifier; the input end of the operational amplifier is connected to the output end of the voltage divider and the shunt resistor, and the output end is connected to the input end of the low-pass filter, and is configured to amplify the signal to a range recognizable by the MCU.

8. The power taking circuit according to claim 7, characterized in that: The load power detection circuit also includes an isolation device; the isolation device is arranged between the operational amplifier and the MCU and is configured to separate the signal source and the MCU to prevent high voltage or fault from being transmitted to sensitive circuits in the MCU.

9. The power taking circuit according to claim 4, characterized in that: The auxiliary power supply circuit also includes a voltage stabilizer; the voltage stabilizer is connected to the output end of the DCDC converter and is configured to stabilize the voltage flowing out of the DCDC converter.

10. The power taking circuit according to claim 2, characterized in that: The power switch is a MOSFET field effect transistor.

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