A reset control circuit and a power supply circuit

Abstract

The utility model relates to a kind of reset control circuit and power supply circuit, and the reset control circuit includes detection circuit and control circuit, wherein, detection circuit is connected with alternating current source, control circuit is connected with the reset end of controller in detection circuit and load circuit respectively, when alternating current source powers on, detection circuit outputs first detection signal, control circuit responds the input of first detection signal, controls controller normal operation, when alternating current source powers off, detection circuit outputs second detection signal, control circuit responds the input of second detection signal, controls controller reset. Therefore, relative to the technical scheme of reset in related art by system self-discharge control, when alternating current source powers off, the reset control circuit controls the controller in load circuit immediately reset, stop running, response speed is faster, can quickly reset, to improve product stability and reliability, and reduce loss, save energy efficiency.

Description

Technical Field

[0001] This utility model relates to the field of power supply, and in particular to a reset control circuit and a power supply circuit. Background Technology

[0002] In various electronic and electrical products today, AC-DC power conversion modules have become core power supply units. They convert AC power into DC power suitable for downstream load circuits through rectification, filtering, and voltage regulation circuits. To achieve smooth voltage after rectification and temporary energy storage, AC-DC power conversion modules are typically equipped with large-capacity energy storage capacitors.

[0003] However, when the AC power is turned off, the energy stored in the capacitor cannot be released instantly. This causes the downstream DC power supply to remain powered on for a period of time before being completely disconnected, making it difficult for the downstream load circuit to reset quickly. Especially when the downstream load circuit is under light load conditions, the capacitor discharges slowly, and the power-off time often lasts for several seconds or even longer. This can easily lead to long reset times and high losses in the downstream load circuit, affecting the stability and reliability of the load circuit and causing resource waste. Utility Model Content

[0004] This utility model aims to provide a reset control circuit and a power supply circuit that can control the load circuit to reset quickly when the AC power is turned off, thereby improving product stability and reducing losses.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solutions: In a first aspect, embodiments of the present invention provide a reset control circuit applied to a power supply circuit, the power supply circuit being used to convert AC power into a first DC power supply to power a load circuit, the reset control circuit comprising: The detection circuit is connected to an AC power supply and is configured to output a first detection signal in response to the AC power supply being powered on and to output a second detection signal in response to the AC power supply being powered off. The control circuit is connected to the reset terminal of the controller in the detection circuit and the load circuit, respectively. It is configured to control the controller to operate normally in response to the input of the first detection signal, and is also configured to control the controller to reset in response to the input of the second detection signal.

[0006] In some embodiments, the detection circuit includes: A rectifier circuit, connected to an AC power source, is configured to rectify the AC power source in response to the power-on of the AC power source to obtain a second DC power source. The optocoupler isolation circuit is connected to the control terminals of the rectifier circuit and the control circuit, respectively, and is configured to output the first detection signal in response to the input of the second DC power supply, and to output the second detection signal in response to the result of the AC power supply being turned off.

[0007] In some embodiments, the optocoupler isolation circuit includes an optocoupler, a first resistor, a second resistor, and a third resistor; The input terminal of the rectifier circuit is connected to the live wire of the AC power supply. The DC output terminal of the rectifier circuit is connected to one end of the first resistor. The other end of the first resistor is connected to one end of the second resistor. The other end of the second resistor is connected to the anode of the diode of the optocoupler. The cathode of the diode of the optocoupler is connected to the neutral wire of the AC power supply. The collector of the transistor of the optocoupler is connected to one end of the third resistor and the control terminal of the control circuit. The other end of the third resistor is connected to the power supply. The emitter of the transistor of the optocoupler is grounded. The rectifier circuit is either a full-wave rectifier circuit or a half-wave rectifier circuit.

[0008] In some embodiments, if the rectifier circuit is a half-wave rectifier circuit, the detection circuit further includes: a unidirectional conduction circuit, wherein the cathode of the unidirectional conduction circuit is connected to the neutral wire of the AC power supply, and the anode of the unidirectional conduction circuit is connected to the optocoupler isolation circuit.

[0009] In some embodiments, the detection circuit further includes: The energy storage circuit, connected to both the rectifier circuit and the optocoupler isolation circuit, is configured to store energy in the second DC power supply and discharge energy in the optocoupler isolation circuit, so that the optocoupler isolation circuit outputs the first detection signal.

[0010] In some embodiments, the energy storage circuit includes a first capacitor, one end of which is connected to the DC output terminal of the rectifier circuit and the first terminal of the optocoupler isolation circuit, and the other end of which is connected to the second terminal of the optocoupler isolation circuit and the neutral wire of the AC power supply.

[0011] In some embodiments, the control circuit includes: a first switching circuit and a second switching circuit; The control terminal of the first switching circuit is connected to the detection circuit and is configured to output a first level signal in response to the input of the first detection signal, and to output a second level signal in response to the input of the second detection signal. The control terminal of the second switching circuit is connected to the first switching circuit. The first terminal of the second switching circuit is connected to the third DC power supply. The second terminal of the second switching circuit is connected to the reset terminal of the controller. The second switching circuit is configured to be in a closed state in response to the input of a first level signal, so as to disconnect the third DC power supply from the reset terminal of the controller and thereby control the controller to operate normally. In response to the input of a second level signal, the second switching circuit is in a closed state, so as to establish a connection between the third DC power supply and the reset terminal of the controller and thereby control the controller to reset.

[0012] In some embodiments, the first switching circuit includes a fourth resistor, a fifth resistor, and a first transistor; One end of the fourth resistor is connected to the detection circuit, and the other end of the fourth resistor is connected to one end of the fifth resistor and the base of the first transistor. The other end of the fifth resistor is grounded together with the emitter of the first transistor, and the collector of the first transistor is connected to the control terminal of the second switching circuit.

[0013] In some embodiments, the second switching circuit includes a sixth resistor, a seventh resistor, a second capacitor, and a first MOSFET; One end of the sixth resistor is connected to the first switching circuit, and the other end of the sixth resistor is connected to the gate of the first MOS transistor, one end of the seventh resistor, and one end of the second capacitor. The drain of the first MOS transistor is connected to the reset terminal of the controller, and the source of the first MOS transistor is connected to the third DC power supply, the other end of the second capacitor, and the other end of the seventh resistor.

[0014] In a second aspect, this utility model embodiment provides a power supply circuit, which includes the reset control circuit described above. The power supply circuit is connected to an AC power supply and a load circuit respectively, and is used to convert the AC power supply into a first DC power supply to power the load circuit.

[0015] In various embodiments of this utility model, the reset control circuit includes a detection circuit and a control circuit. The detection circuit is connected to an AC power supply, and the control circuit is connected to both the detection circuit and the reset terminal of the controller in the load circuit. When the AC power supply is powered on, the detection circuit outputs a first detection signal, and the control circuit responds to the input of the first detection signal, controlling the controller to operate normally. When the AC power supply is powered off, the detection circuit outputs a second detection signal, and the control circuit responds to the input of the second detection signal, controlling the controller to reset. Therefore, compared to the related technology that relies on system self-discharge to control reset, this reset control circuit immediately resets and stops the controller in the load circuit when the AC power supply is powered off, resulting in a faster response speed and rapid reset, thereby improving product stability and reliability, reducing losses, and saving energy. Attached Figure Description

[0016] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0017] Figure 1 This is a schematic diagram of the structure of one of the power supply circuits provided in this embodiment of the utility model; Figure 2 This is a schematic diagram of the structure of one of the reset control circuits provided in this embodiment of the utility model; Figure 3 This is a schematic diagram of the structure of one of the reset control circuits provided in this embodiment of the utility model; Figure 4 This is a schematic diagram of the circuit structure of one of the detection circuits provided in this embodiment of the utility model; Figure 5 This is a schematic diagram of the circuit structure of one of the control circuits provided in this embodiment of the utility model. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this utility model and are not intended to limit this utility model.

[0019] Please see Figure 1 , Figure 1 This is a schematic diagram of a power supply circuit provided in an embodiment of the present invention, as shown below. Figure 1As shown, the power supply circuit 100 is connected to both the AC power supply 200 and the load circuit 300. The power supply circuit 100 converts the AC power supply 200 into a first DC power supply, which is used to supply power to the load circuit 300. The power supply circuit 100 is generally located on the power supply board, while the load circuit 300 is generally located on the main board / control board.

[0020] The power supply circuit 100 can be various types of AC-DC circuits. For example, if the power supply circuit 100 is a switching power supply circuit, when the power supply circuit 100 is connected to the AC power supply 200, the power supply circuit 100 first converts the connected AC power supply 200 into high-voltage DC power through EMI filtering and rectification filtering, and then drives the switching transistor through the PWM controller to invert it into high-frequency AC power. After being stepped down by the high-frequency transformer, it is converted into low-voltage pulsating DC power by the secondary rectification and filtering circuit. Finally, a stable DC output is achieved through the feedback regulation mechanism to provide the load circuit 300 with a power supply that meets the voltage and current requirements.

[0021] The power supply circuit 100 converts the 220V AC power supply 200 into a first DC power supply, which serves as the basic power supply for the load circuit 300, typically 12V or 24V. The load circuit 300 includes various electrical components such as controllers, sensors, actuators, and display devices. Each component requires a different power supply voltage; for example, the controller requires 3.3V or 5V, the sensor requires 3.3V, 5V, or 9V, the actuator requires 12V or 9V, and the display device requires 5V or 3.3V. Therefore, the load circuit 300 can use a linear regulator to distribute independent voltages to each electrical component, avoiding power supply interference between different modules.

[0022] To achieve voltage smoothing after rectification and temporary energy storage, the power supply circuit typically includes an energy storage capacitor connected to the output of the rectifier module. When the AC power supply is powered on, the rectifier module rectifies the AC power supply and outputs DC power. The DC power charges the energy storage capacitor. When the AC power supply is powered off, the energy stored in the energy storage capacitor continuously discharges to the load circuit, causing the load circuit to remain powered on for a period of time before being completely de-energized. The controller in the load circuit will continue to work for a period of time, the duration of which is the discharge time of the energy storage capacitor. This can easily lead to problems such as long controller reset time and high losses, and is also detrimental to the stability and reliability of the load circuit and wastes resources.

[0023] To address the aforementioned issues, this utility model provides a reset control circuit applied to a power supply circuit. This circuit can quickly reset the controller in the load circuit when the AC power is turned off, causing the controller to stop working, thereby improving the stability and reliability of the load circuit and saving energy.

[0024] Specifically, such as Figure 1 As shown, the reset control circuit 10 includes a detection circuit 11 and a control circuit 12. The detection circuit 11 is connected to the AC power supply 200 and the control terminal of the control circuit 12, respectively. The detection circuit 11 is used to detect whether the AC power supply 200 is powered off. When the AC power supply 200 is powered on, the detection circuit 11 outputs a first detection signal. When the AC power supply 200 is powered off, the detection circuit 11 outputs a second detection signal.

[0025] The first detection signal and the second detection signal are signals with different voltage levels; for example, the first detection signal is a low-level signal and the second detection signal is a high-level signal. Therefore, the detection signal output by the detection circuit 11 can characterize whether the AC power supply 200 is in a powered-on or powered-off state.

[0026] The control terminal of the control circuit 12 is connected to the output terminal of the detection circuit 11. The output terminal of the control circuit 12 is also connected to the reset terminal of the controller 301 in the load circuit. When the first detection signal is input, the control circuit 12 controls the controller 301 to operate normally. When the second detection signal is input, the control circuit 12 controls the controller 301 to reset.

[0027] When the AC power supply 200 is powered on, the control circuit 12 controls the controller 301 to operate normally, and the load circuit 300 is in normal operating condition. When the AC power supply 200 is powered off, the control circuit 12 controls the controller 301 to reset, and the controller 301 stops operating. Thus, when the AC power supply 200 is powered off, the reset control circuit 10 realizes the power-off reset of the controller 301 in the load circuit 300. Compared with the related technology of controlling the reset by system self-discharge, the reset control circuit 10 uses hardware circuit to control the reset of the controller 301, which has a faster response speed. Moreover, the reset control circuit 10 directly controls the reset terminal of the controller 301, resulting in a higher reset success rate.

[0028] Therefore, when the AC power supply 200 is powered off, the reset control circuit 10 controls the controller 301 in the load circuit to reset immediately and stop running. The response speed is faster and the system can reset quickly, thereby improving product stability and reliability, reducing losses, and saving energy.

[0029] In some embodiments, please refer to Figure 2 , Figure 2 This is a schematic diagram of a reset control circuit provided in an embodiment of the present invention, as shown below. Figure 2As shown, the detection circuit 11 includes a rectifier circuit 111 and an optocoupler isolation circuit 112. The rectifier circuit 111 is connected to the live wire of the AC power supply 200. The first terminal of the optocoupler isolation circuit 112 is connected to the rectifier circuit 111. The second terminal of the optocoupler isolation circuit 112 is connected to the neutral wire of the AC power supply 200. The third terminal of the optocoupler isolation circuit 112 is connected to the power supply VCC and the control terminal of the control circuit 12, respectively. The fourth terminal of the optocoupler isolation circuit 112 is grounded.

[0030] When the AC power supply 200 is powered on, the rectifier circuit 111 rectifies the AC power supply 200 to obtain a second DC power supply. The second DC power supply is input to the optocoupler isolation circuit 112, and the optocoupler isolation circuit 112 outputs a first detection signal. When the AC power supply 200 is powered off, there is no power input at the input terminal of the rectifier circuit 111, so it cannot output the second DC power supply. Therefore, there is no power input at the input terminal of the optocoupler isolation circuit 112, and the optocoupler isolation circuit 112 outputs a second detection signal.

[0031] In some embodiments, the rectifier circuit 111 is a full-wave rectifier circuit, which is either a full-bridge rectifier circuit composed of four diodes or a half-bridge rectifier circuit composed of two diodes and two capacitors. In some embodiments, the rectifier circuit 111 is a half-wave rectifier circuit, which is composed of a single diode to achieve rectification.

[0032] The optocoupler isolation circuit 112 primarily serves a dual function: electrical isolation and signal transmission. On one hand, the second DC power supply operates at high voltage. The rectifier circuit 111 is on the high-voltage side, while the control circuit 12 is on the low-voltage side. The optocoupler isolation circuit 112 achieves electrical isolation between the high-voltage and low-voltage sides, cutting off their direct circuit connection and preventing noise, surges, or fault voltages from the high-voltage side from entering the low-voltage control circuit 12, thus protecting sensitive components such as the control chip. On the other hand, the optocoupler isolation circuit 112 can accurately transmit signals, transmitting the status information of the rectifier circuit 111 to the control circuit 12, i.e., transmitting the status information of the AC power supply 200 to the control circuit 12. This satisfies both the safety isolation requirements of the high and low voltage circuits and enables effective signal interaction.

[0033] In some embodiments, if the rectifier circuit 111 is a half-wave rectifier circuit, in order to prevent the AC power supply 200 from being reverse-connected to the rectifier circuit 111 and affecting the operation of other subsequent circuits, such as... Figure 2 As shown, the detection circuit 11 also includes a unidirectional conduction circuit 113, the cathode of which is connected to the neutral wire of the AC power supply 200, and the anode of which is connected to the second end of the optocoupler isolation circuit 112.

[0034] The unidirectional conduction circuit 113 can prevent the AC power supply 200 from being reversed, and prevent damage to subsequent circuits such as the optocoupler isolation circuit 112 caused by the AC power supply 200 being reversed, thereby improving the safety and reliability of the reset control circuit 10.

[0035] In some embodiments, if the rectifier circuit 111 is a half-wave rectifier circuit, when the AC power supply 200 is in the positive half-cycle, the half-wave rectifier circuit rectifies the AC power supply 200. When the AC power supply 200 is in the negative half-cycle, the half-wave rectifier circuit has no output, and the input terminal of the optocoupler isolation circuit 112 has no input. The optocoupler isolation circuit 112 will also output the second detection signal, causing false detection.

[0036] Even when the rectifier circuit 111 is a full-wave rectifier circuit, the rectifier circuit 111 rectifies the AC power supply 200 to output a second DC power supply. However, fluctuations in the AC power supply 200 can easily cause fluctuations in the second DC power supply, thereby affecting the reliability of the circuit operation.

[0037] Based on the above issues, such as Figure 2 As shown, the detection circuit 11 also includes an energy storage circuit 114, which is connected to the rectifier circuit 111 and the optocoupler isolation circuit 112.

[0038] When AC power supply 200 is powered on, during the positive half-cycle, rectifier circuit 111 rectifies AC power supply 200 to output a second DC power supply, while energy storage circuit 114 stores energy in the second DC power supply. During the negative half-cycle, energy storage circuit 114 discharges the stored energy to optocoupler isolation circuit 112. Since the input of optocoupler isolation circuit 112 is the discharge current, it outputs a first detection signal to prevent false detections during the negative half-cycle of AC power supply 200, thus improving detection accuracy.

[0039] Meanwhile, the energy storage circuit 114 can stabilize the second DC power supply output by the rectifier circuit 111, making the second DC power supply more stable, thereby improving the reliability and stability of the circuit operation.

[0040] Please see Figure 3 , Figure 3 This is a schematic diagram of a reset control circuit provided in an embodiment of the present invention, as shown below. Figure 3As shown, the control circuit 12 includes a first switch circuit 121 and a second switch circuit 122. The control terminal of the first switch circuit 121 is connected to the detection circuit 11. The first terminal of the first switch circuit 121 is connected to the third DC power supply V3 and the control terminal of the second switch circuit 122 respectively. The second terminal of the first switch circuit 121 is grounded. The first terminal of the second switch circuit 122 is connected to the third DC power supply V3. The second terminal of the second switch circuit 122 is connected to the reset terminal of the controller 301.

[0041] The first switching circuit 121 and the second switching circuit 122 can be any type of switching transistor, such as a transistor, MOSFET, thyristor, etc. The control terminal of the first switching circuit 121 receives a first detection signal or a second detection signal, and the first detection signal and the second detection signal control the first switching circuit 121 to turn on or off.

[0042] In this embodiment, when the first switch circuit 121 is in the on state, the control terminal of the second switch circuit 122 is connected to ground, and the first switch circuit 121 outputs a low-level second-level signal. When the first switch circuit 121 is in the off state, the control terminal of the second switch circuit 122 is connected to the third DC power supply V3, and the first switch circuit 121 outputs a high-level first-level signal.

[0043] When the AC power supply 200 is powered on, the detection circuit 11 outputs a first detection signal. The first detection signal acts on the first switch circuit 121, causing the first switch circuit 121 to output a first level signal. The first level signal acts on the control terminal of the second switch circuit 122, controlling the second switch circuit 122 to turn off. Then, the third DC power supply V3 is disconnected from the reset terminal of the controller 301, and there is no signal input to the reset terminal of the controller 301. The controller 301 operates normally.

[0044] When the AC power supply 200 is powered off, the detection circuit 11 outputs a second detection signal. The second detection signal acts on the first switching circuit 121, causing the first switching circuit 121 to output a second level signal. The second level signal acts on the control terminal of the second switching circuit 122, controlling the second switching circuit 122 to conduct. Then, a connection is established between the third DC power supply V3 and the reset terminal of the controller 301. The reset terminal of the controller 301 receives the third DC power supply V3, and the controller 301 quickly resets.

[0045] It should be noted that in this embodiment, the first level signal is a high-level signal provided by the third DC power supply V3, and the second level signal is a low-level signal provided by ground. In other embodiments, the circuit connection relationship or composition of the first switch circuit 121 and the second switch circuit 122 can be changed. The first level signal can be a low-level signal, and the second level signal can be a high-level signal, as long as it ensures that when the first switch circuit 121 outputs the first level signal, there is no signal input at the reset terminal of the controller 301, and when the first switch circuit 121 outputs the second level signal, the reset terminal of the controller 301 is connected to the third DC power supply V3.

[0046] Please see Figure 4 , Figure 4 This is a schematic diagram of the circuit structure of a detection circuit provided in an embodiment of this utility model, as shown below. Figure 4 As shown, the optocoupler isolation circuit 112 includes optocoupler U5-A, a first resistor R28, a second resistor R30, and a third resistor R31. The rectifier circuit 111 includes a first diode DA. The anode of the first diode DA is connected to the live wire AC-L of the AC power supply 200. The cathode of the first diode DA is connected to one end of the first resistor R28. The other end of the first resistor R28 is connected to one end of the second resistor R30. The other end of the second resistor R30 is connected to the anode of the diode of optocoupler U5-A. The cathode of the diode of optocoupler U5-A is connected to the neutral wire AC-N of the AC power supply 200. The collector of the transistor of optocoupler U5-A is connected to one end of the third resistor R31 and the control terminal of the control circuit 12. The other end of the third resistor R31 is connected to the power supply VCC. The emitter of the transistor of optocoupler U5-A is grounded.

[0047] The unidirectional conduction circuit 113 includes a second diode DB, and the energy storage circuit 114 includes a first capacitor CX2. One end of the first capacitor CX2 is connected to the cathode of the first diode DA and one end of the first resistor R28, respectively. The other end of the first capacitor CX2 is connected to the anode of the second diode DB and the cathode of the diode of the optocoupler U5-A, respectively. The cathode of the second diode DB is connected to the neutral line of the AC power supply 200.

[0048] Please see Figure 5 , Figure 5 This is a circuit structure diagram of a control circuit provided in an embodiment of the present invention, as shown below. Figure 5As shown, the first switching circuit 121 includes a fourth resistor R22, a fifth resistor R23, and a first transistor Q21, and the second switching circuit 122 includes a sixth resistor R21, a seventh resistor R20, a second capacitor C20, and a first MOSFET Q20. One end of the fourth resistor R22 is connected to the collector of the transistor in optocoupler U5-A. The other end of the fourth resistor R22 is connected to one end of the fifth resistor R23 and the base of the first transistor Q21. The other end of the fifth resistor R23 is grounded together with the emitter of the first transistor Q21. The collector of the first transistor Q21 is connected to one end of the sixth resistor R21. The other end of the sixth resistor R21 is connected to the gate of the first MOSFET Q20, one end of the seventh resistor R20, and one end of the second capacitor C20. The drain of the first MOSFET Q20 is connected to the reset terminal (MCU_RSTP pin) of the controller 301. The source of the first MOSFET Q20 is connected to the third DC power supply V3, the other end of the second capacitor C20, and the other end of the seventh resistor R20.

[0049] In this embodiment, the power supply VCC can be provided by the first DC power supply, and the third DC power supply V3 can be obtained by converting the first DC power supply, such as the voltage of the third DC power supply V3 being 3.3V. Therefore, for ease of installation, the detection circuit 11 can be located on the power supply board, and the control circuit 12 can be located on the main board / control board.

[0050] Combination Figure 4 and Figure 5 The working principle of the reset control circuit 10 can be described as follows: When AC power supply 200 is powered on, the first diode DA rectifies AC power supply 200 to obtain second DC power supply. The second DC power supply charges the first capacitor CX2. The second DC power supply provides operating current to optocoupler U5-A through the current limiting of the first resistor R28 and the second resistor R30, causing the diode of optocoupler U5-A to light up. As a result, the transistor of optocoupler U5-A is turned on, and optocoupler U5-A outputs a low-level first detection signal.

[0051] A low-level first detection signal is applied to the base of the first transistor Q21, turning off the first transistor Q21. This results in a high-level first signal being output, provided by the third DC power supply V3. The high-level first signal controls the first MOSFET Q20 to turn off, disconnecting the reset terminal of controller 301 from the third DC power supply V3. With no signal input to the reset terminal of controller 301, controller 301 operates normally.

[0052] When AC power supply 200 is turned off, the first diode DA cannot output the second DC power supply. The operating current at the diode of optocoupler U5-A decreases rapidly, the diode of optocoupler U5-A turns off, the transistor of optocoupler U5-A is cut off, and a high-level second detection signal is output. The high-level second detection signal is provided by the power supply VCC connected to the collector of the transistor of optocoupler U5-A.

[0053] A high-level second detection signal is applied to the base of the first transistor Q21, turning on the first transistor Q21. This connects the gate of the first MOSFET Q20 to ground, pulling down the gate potential of the first MOSFET Q20. As a result, the first transistor Q21 outputs a low-level second signal, turning on the first MOSFET Q20. This establishes a connection between the third DC power supply V3 and the reset terminal of the controller 301. The reset terminal of the controller 301 is then connected to a high-level signal, resetting the controller 301. This achieves the purpose of quickly powering off and resetting the controller 301 when the AC power supply 200 is powered off.

[0054] In summary, when the AC power is turned off, the reset control circuit immediately resets the controller in the load circuit and stops operating. This results in a faster response speed and quicker reset, thereby improving product stability and reliability, reducing losses, and saving energy.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it; under the concept of this utility model, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of this utility model as described above, which are not provided in detail for the sake of brevity; although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A reset control circuit, characterized in that, The reset control circuit is applied to a power supply circuit, which converts AC power into a first DC power supply to power the load circuit. The detection circuit is connected to an AC power supply and is configured to output a first detection signal in response to the AC power supply being powered on and to output a second detection signal in response to the AC power supply being powered off. The control circuit is connected to the reset terminal of the controller in the detection circuit and the load circuit, respectively. It is configured to control the controller to operate normally in response to the input of the first detection signal, and is also configured to control the controller to reset in response to the input of the second detection signal.

2. The reset control circuit according to claim 1, characterized in that, The detection circuit includes: A rectifier circuit, connected to an AC power source, is configured to rectify the AC power source in response to power-on of the AC power source to obtain a second DC power source. The optocoupler isolation circuit is connected to the control terminals of the rectifier circuit and the control circuit, respectively, and is configured to output the first detection signal in response to the input of the second DC power supply, and to output the second detection signal in response to the result of the AC power supply being turned off.

3. The reset control circuit according to claim 2, characterized in that, The optocoupler isolation circuit includes an optocoupler, a first resistor, a second resistor, and a third resistor; The input terminal of the rectifier circuit is connected to the live wire of the AC power supply. The DC output terminal of the rectifier circuit is connected to one end of the first resistor. The other end of the first resistor is connected to one end of the second resistor. The other end of the second resistor is connected to the anode of the diode of the optocoupler. The cathode of the diode of the optocoupler is connected to the neutral wire of the AC power supply. The collector of the transistor of the optocoupler is connected to one end of the third resistor and the control terminal of the control circuit. The other end of the third resistor is connected to the power supply. The emitter of the transistor of the optocoupler is grounded. The rectifier circuit is either a full-wave rectifier circuit or a half-wave rectifier circuit.

4. The reset control circuit according to claim 3, characterized in that, If the rectifier circuit is a half-wave rectifier circuit, the detection circuit further includes: a unidirectional conduction circuit, the cathode of the unidirectional conduction circuit being connected to the neutral wire of the AC power supply, and the anode of the unidirectional conduction circuit being connected to the optocoupler isolation circuit.

5. The reset control circuit according to claim 2, characterized in that, The detection circuit further includes: The energy storage circuit, connected to both the rectifier circuit and the optocoupler isolation circuit, is configured to store energy in the second DC power supply and discharge energy in the optocoupler isolation circuit, so that the optocoupler isolation circuit outputs the first detection signal.

6. The reset control circuit according to claim 5, characterized in that, The energy storage circuit includes a first capacitor, one end of which is connected to the DC output terminal of the rectifier circuit and the first terminal of the optocoupler isolation circuit, and the other end of which is connected to the second terminal of the optocoupler isolation circuit and the neutral wire of the AC power supply.

7. The reset control circuit according to claim 1, characterized in that, The control circuit includes: a first switching circuit and a second switching circuit; The control terminal of the first switching circuit is connected to the detection circuit and is configured to output a first level signal in response to the input of the first detection signal, and to output a second level signal in response to the input of the second detection signal. The control terminal of the second switching circuit is connected to the first switching circuit. The first terminal of the second switching circuit is connected to the third DC power supply. The second terminal of the second switching circuit is connected to the reset terminal of the controller. The second switching circuit is configured to be in a closed state in response to the input of a first level signal, so as to disconnect the third DC power supply from the reset terminal of the controller and thereby control the controller to operate normally. In response to the input of a second level signal, the second switching circuit is in a closed state, so as to establish a connection between the third DC power supply and the reset terminal of the controller and thereby control the controller to reset.

8. The reset control circuit according to claim 7, characterized in that, The first switching circuit includes a fourth resistor, a fifth resistor, and a first transistor; One end of the fourth resistor is connected to the detection circuit, and the other end of the fourth resistor is connected to one end of the fifth resistor and the base of the first transistor. The other end of the fifth resistor is grounded together with the emitter of the first transistor, and the collector of the first transistor is connected to the control terminal of the second switching circuit.

9. The reset control circuit according to claim 8, characterized in that, The second switching circuit includes a sixth resistor, a seventh resistor, a second capacitor, and a first MOSFET; One end of the sixth resistor is connected to the first switching circuit, and the other end of the sixth resistor is connected to the gate of the first MOS transistor, one end of the seventh resistor, and one end of the second capacitor. The drain of the first MOS transistor is connected to the reset terminal of the controller, and the source of the first MOS transistor is connected to the third DC power supply, the other end of the second capacitor, and the other end of the seventh resistor.

10. A power supply circuit, characterized in that, The power supply circuit includes a reset control circuit as described in any one of claims 1-9. The power supply circuit is connected to an AC power source and a load circuit, respectively, and is used to convert the AC power source into a first DC power source to power the load circuit.

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