Power switching circuit and electronic device

Abstract

The application discloses a power switching circuit and electronic equipment. The power switching circuit comprises a relay, a detection feedback module and a master control module. The first end of the contact of the relay is used for being connected with an alternating current power supply, the second end of the contact of the relay is used for being connected with a load, the first end of the coil of the relay is connected with a first working voltage, and the second end of the coil of the relay is connected with the first end of the master control module. The input end of the detection feedback module is connected with the first end of the contact of the relay, and the output end of the detection feedback module is connected with the second end of the master control module. When the feedback signal jumps from a first level to a second level or the second level to the first level, that is, the zero-crossing moment of the positive and negative half cycles of the alternating voltage, the master control module accurately triggers the relay to act at this moment, so that the contact completes the attraction or release in the transient state when the voltage and the current approach zero, and the arc energy and the contact wear can be greatly reduced.

Description

Technical Field

[0001] This application belongs to the field of power supply circuit technology, and particularly relates to power switching circuits and electronic equipment. Background Technology

[0002] When a switching device connecting an AC power supply and a load undergoes a state change (e.g., from on to off or from off to on), if the instantaneous voltage supplied by the AC power supply is too high at this time, it may damage the switching device and reduce its service life. Summary of the Invention

[0003] The purpose of this application is to provide a power switching circuit and electronic device, which aims to solve the problem of easy damage to switching devices when they are switching states.

[0004] The first aspect of this application provides a power switching circuit, including: a relay, a detection feedback module, and a main control module; The first end of the relay contact is used to connect to the AC power supply, the second end of the relay contact is used to connect to the load, the first end of the relay coil is connected to the first operating voltage, and the second end of the relay coil is connected to the first end of the main control module. The input terminal of the detection feedback module is connected to the first terminal of the relay contact, and the output terminal of the detection feedback module is connected to the second terminal of the main control module. The detection feedback module is used to output a feedback signal based on the voltage of the first terminal of the relay contact. The feedback signal is at a first level when the voltage at the first terminal of the relay contact is greater than zero, and at a second level when the voltage at the first terminal of the relay contact is less than zero. The main control module is used to control the connection or disconnection between the second terminal of the relay coil and the ground terminal when the feedback signal undergoes a level shift, according to the control command.

[0005] In one embodiment, the detection feedback module includes a waveform conversion unit and an isolation unit; The input terminal of the waveform conversion unit is connected to the first terminal of the relay contact, the output terminal of the waveform conversion unit is connected to the input terminal of the isolation unit, and the output terminal of the isolation unit is connected to the second terminal of the main control module. The waveform conversion unit is used to convert AC signals into square wave signals.

[0006] In one embodiment, the waveform conversion unit includes: a first capacitor, a first resistor, a second resistor, a third resistor, and a first switching device; The first end of the first capacitor is connected to the first end of the contact of the relay, the second end of the first capacitor is connected to the first end of the first resistor, the second end of the first resistor is connected to the first end of the second resistor and the control end of the first switching device, the second end of the second resistor and the first end of the first switching device are both connected to the second operating voltage, the second end of the first switching device is connected to the first end of the third resistor, and the second end of the third resistor is connected to the input end of the isolation unit.

[0007] In one embodiment, the isolation unit includes an optocoupler and a fourth resistor; The anode of the optocoupler is connected to the output terminal of the waveform conversion unit, the cathode of the optocoupler is grounded, the collector of the optocoupler is grounded, the emitter of the optocoupler is connected to the second terminal of the main control module and the first terminal of the fourth resistor, and the second terminal of the fourth resistor is connected to the third operating voltage.

[0008] In one embodiment, the main control module includes a main control chip, a fifth resistor, a sixth resistor, and a second switching device; The main control chip is connected to the output terminal of the detection feedback module and the first terminal of the fifth resistor. The second terminal of the fifth resistor is connected to the first terminal of the sixth resistor and the control terminal of the second switching device. The second terminal of the sixth resistor is grounded. The first terminal of the second switching device is connected to the second terminal of the coil of the relay. The second terminal of the second switching device is grounded. The first end of the relay coil is connected to the first operating voltage via a seventh resistor.

[0009] In one embodiment, the power switching circuit further includes a fuse; The fuse is connected in series between the input terminal of the detection feedback module and the first terminal of the relay contact.

[0010] In one embodiment, the power switching circuit further includes a second capacitor, and the first end of the AC power supply is connected to the first end of the relay contact. The first terminal of the second capacitor is connected to the first terminal of the AC power supply, and the second terminal of the second capacitor is connected to the second terminal of the AC power supply.

[0011] In one embodiment, the power switching circuit further includes a voltage conversion module, the input terminal of which is connected to the AC power supply, and the voltage conversion module is used to generate and output the first operating voltage based on the electrical energy provided by the AC power supply.

[0012] In one embodiment, the voltage conversion module is also connected to the detection feedback module, and the voltage conversion module is also used to output a second working voltage and a third working voltage.

[0013] A second aspect of this application provides an electronic device including the power switching circuit described above.

[0014] The beneficial effects of this application embodiment compared with the prior art are: when the feedback signal jumps from the first level to the second level or from the second level to the first level, it is the zero-crossing moment of the alternation of positive and negative half-cycles of AC voltage. At this time, the main control module accurately triggers the relay action, so that the contacts complete the engagement or release in the transient state when the voltage and current approach zero, which can greatly reduce arc energy and contact wear. Attached Figure Description

[0015] Figure 1 A schematic diagram of a power switching circuit provided in an embodiment of this application; Figure 2 This is another schematic diagram of a power switching circuit provided in an embodiment of this application; Figure 3 A circuit diagram of a power switching circuit provided in an embodiment of this application; Figure 4 This is a schematic diagram of an electronic device provided in an embodiment of this application.

[0016] Figure descriptions: 10. Power switching circuit; 20. AC power supply; 30. Load; 40. Electronic equipment; 100. Detection feedback module; 110. Waveform conversion unit; 120. Isolation unit; 200. Main control module; 300. Voltage conversion module. Detailed Implementation

[0017] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0018] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0019] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0020] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0021] Figure 1 A schematic diagram of a power switching circuit according to an embodiment of this application is shown. For ease of explanation, only the parts relevant to this embodiment are shown, and are described in detail below: A power switching circuit 10 includes: a relay, a detection feedback module 100, and a main control module 200.

[0022] The first terminal of the relay contact K1 is used to connect to the AC power supply 20, the second terminal of the relay contact K1 is used to connect to the load 30, the first terminal of the relay coil L1 is connected to the first operating voltage V1, and the second terminal of the relay coil L1 is connected to the first terminal of the main control module 200. The AC power supply 20 can be a 120V~220V AC mains power supply.

[0023] The input terminal of the detection feedback module 100 is connected to the first terminal of the relay contact K1, and the output terminal of the detection feedback module 100 is connected to the second terminal of the main control module 200. The detection feedback module 100 is used to output a feedback signal based on the voltage of the first terminal of the relay contact K1.

[0024] The feedback signal is at the first level when the voltage at the first terminal of the relay contact K1 is greater than zero, and at the second level when the voltage at the first terminal of the relay contact K1 is less than zero.

[0025] The main control module 200 is used to control the connection or disconnection between the second terminal of the relay coil L1 and the ground terminal when the feedback signal undergoes a level transition, according to the control command.

[0026] It is understandable that when the feedback signal jumps from the first level to the second level or from the second level to the first level, it is the zero-crossing moment of the alternating positive and negative half-cycles of the AC voltage. At this time, the main control module 200 accurately triggers the relay to operate, so that the contact K1 completes the engagement or release in the transient state when the voltage and current approach zero, which can greatly reduce the arc energy and the wear of the contact K1.

[0027] For example, in one embodiment, the power switching circuit 10 can be used to implement a power switching method.

[0028] The power switching method includes steps S100~S300.

[0029] Step S100: Obtain the time for each level transition of the feedback signal.

[0030] Step S200: Determine the electrical parameters of AC power supply 20 based on the level transition time.

[0031] Specifically, in some embodiments, the electrical parameters of the AC power supply 20 include frequency and phase. In step S200, the frequency of the AC power supply 20 can be determined based on the interval between each level transition or the number of level transitions within a certain time. The phase of the AC power supply 20 is determined based on the power-on time of the main control module 200 or the first rising edge of the feedback signal, according to the time of each level transition.

[0032] Step S300: Based on the electrical parameters of AC power supply 20 and control commands, when the feedback signal undergoes a level transition, control the connection or disconnection between the second terminal of the relay coil L1 and the ground terminal.

[0033] After determining the electrical parameters of the AC power supply 20, the main control module 200 can determine a target zero point and the time of the target zero point according to the control command. Then, within a certain window time before and after the target zero point, it controls the conduction or cutoff between the second terminal of the control relay coil L1 and the ground terminal, thereby controlling the contact K1 to complete the engagement or release.

[0034] Specifically, in some embodiments, the main control module 200 can be configured, according to a control command, to control contact K1 to close within a preset time after power-on, thereby connecting the power supply circuit between the AC power supply 20 and the load 30. The main control module 200 can also be configured to control contact K1 to close after receiving a control command, thereby connecting the power supply circuit between the AC power supply 20 and the load 30. The control logic of the main control module 200 can be set according to actual needs, and this application embodiment does not limit it.

[0035] In some embodiments, the power switching method further includes step S400.

[0036] Step S300: Within a preset time period after any level transition, if no level transition is detected, the second terminal of the control relay coil L1 is disconnected from the ground terminal. This releases the control contact K1, thereby cutting off the power supply circuit between the AC power supply 20 and the load 30.

[0037] Understandably, when the AC power supply 20 experiences a power outage or other fault, step S300 can enable rapid fault identification, allowing the main control module 200 to perform data saving and other operations, and control the relay to switch the power supply.

[0038] In one embodiment, such as Figure 2 As shown, the detection feedback module 100 includes a waveform conversion unit 110 and an isolation unit 120.

[0039] The input terminal of the waveform conversion unit 110 is connected to the first terminal of the relay contact K1, the output terminal of the waveform conversion unit 110 is connected to the input terminal of the isolation unit 120, and the output terminal of the isolation unit 120 is connected to the second terminal of the main control module 200.

[0040] The waveform conversion unit 110 is used to convert AC signals into square wave signals.

[0041] The waveform conversion unit 110 shapes the sinusoidal AC signal into a square wave electrical signal, and its transition edge strictly corresponds to the voltage zero crossing point; the isolation unit 120 can realize electrical isolation to ensure the safe operation of the main control module 200.

[0042] In one embodiment, such as Figure 3 As shown, the waveform conversion unit 110 includes: a first capacitor C1, a first resistor R1, a second resistor R2, a third resistor R3, and a first switching device Q1.

[0043] The first terminal of the first capacitor C1 is connected to the first terminal of the relay contact K1. The second terminal of the first capacitor C1 is connected to the first terminal of the first resistor R1. The second terminal of the first resistor R1 is connected to the first terminal of the second resistor R2 and the control terminal of the first switching device Q1. The second terminal of the second resistor R2 and the first terminal of the first switching device Q1 are both connected to the second operating voltage V2. The second terminal of the first switching device Q1 is connected to the first terminal of the third resistor R3. The second terminal of the third resistor R3 is connected to the input terminal of the isolation unit 120.

[0044] Specifically, the first switching device Q1 can be a PNP transistor.

[0045] It should be noted that when the voltage at the first terminal of the relay contact K1 is greater than zero, the first switching device Q1 is turned off, and there is no voltage drop across the third resistor R3, so the input of the isolation unit 120 is at a low level. When the voltage is less than zero, the first switching device Q1 is turned on, a voltage drop occurs across the third resistor R3, and the input of the isolation unit 120 jumps to a high level. This level switching process precisely maps the zero-crossing point of the AC cycle, so that the isolation unit 120 can output a corresponding feedback signal to the main control module 200 according to this level change.

[0046] In one embodiment, such as Figure 3 As shown, the isolation unit 120 includes an optocoupler U1 and a fourth resistor R4.

[0047] The anode of optocoupler U1 is connected to the output terminal of waveform conversion unit 110, the cathode of optocoupler U1 is grounded, the collector of optocoupler U1 is grounded, the emitter of optocoupler U1 is connected to the second terminal of main control module 200 and the first terminal of fourth resistor R4 respectively, and the second terminal of fourth resistor R4 is connected to the third working voltage V3.

[0048] When the anode of optocoupler U1 is at a high level, optocoupler U1 is turned on, and the emitter and collector are connected, thereby grounding the second terminal of the main control module 200. At this time, the feedback signal is at the second level. When the anode of optocoupler U1 is at a low level, optocoupler U1 is turned off, the emitter is floating or in a high-impedance state, and the fourth resistor R4 pulls the second terminal of the main control module 200 up to the third operating voltage V3. At this time, the feedback signal is at the first level.

[0049] The isolation unit 120 enables electrical isolation between high-voltage and low-voltage circuits, effectively suppressing the impact of power grid interference, surges, and common-mode noise on the main control module 200. This ensures that the main control module 200 can stably identify zero-crossing signals and optimize the steepness of the signal rising edge in complex power grid environments, thereby improving the accuracy and response speed of zero-crossing detection.

[0050] In one embodiment, such as Figure 3 As shown, the main control module 200 includes a main control chip U2, a fifth resistor R5, a sixth resistor R6, and a second switching device Q2.

[0051] The main control chip U2 is connected to the output terminal of the detection feedback module 100 and the first terminal of the fifth resistor R5. The second terminal of the fifth resistor R5 is connected to the first terminal of the sixth resistor R6 and the control terminal of the second switching device Q2. The second terminal of the sixth resistor R6 is grounded. The first terminal of the second switching device Q2 is connected to the second terminal of the relay coil L1. The second terminal of the second switching device Q2 is grounded.

[0052] The first terminal of the relay coil L1 is connected to the first operating voltage V1 through the seventh resistor R7.

[0053] It is understandable that when the main control chip U2 controls the second switching device Q2 to be turned on, the relay coil L1 forms a complete circuit, generating a magnetic attraction force to make the contact K1 actuate; when the main control chip U2 controls the second switching device Q2 to be turned off, the current in the coil L1 decays rapidly, and the contact K1 is reset.

[0054] Based on the feedback signal from the isolation unit 120, the main control chip U2 accurately outputs drive pulses within a certain window time before and after the zero crossing point, so that the relay only completes the engagement or disengagement in the transient state when the voltage approaches zero, which significantly reduces the arc energy and mechanical stress of the contact K1 and extends its service life.

[0055] In some embodiments, the main control chip U2 can also determine the power supply status of the AC power supply 20 based on the timing characteristics of the feedback signal. For example, it can determine whether the frequency of the AC power supply 20 is 50Hz or 60Hz, and dynamically adjust the zero-crossing detection window according to the frequency of the AC power supply 20. If no valid zero-crossing signal is detected for 200ms, it is determined that the mains power is interrupted, and the main control chip U2 can trigger the power-off memory preservation mechanism to ensure that the relay state is accurately restored after the power supply is restored.

[0056] In some embodiments, the main control chip U2 is provided with a working voltage terminal, which is used to receive a third working voltage V3. The third working voltage V3 is also used to power the main control chip U2. The main control module 200 also includes an energy storage capacitor, the first end of which is connected to the working voltage terminal, and the second end of which is grounded.

[0057] It is understandable that when AC power supply 20 experiences a power failure, the energy storage capacitor can maintain the third working voltage V3 for a certain period of time, and the feedback signal will remain at a high level. The main control chip U2 can then identify the power failure, and the energy storage capacitor can provide a certain amount of power to the power failure memory retention mechanism of the main control chip U2.

[0058] In one embodiment, such as Figure 3 As shown, the power switching circuit 10 also includes a fuse F1.

[0059] Fuse F1 is connected in series between the input terminal of the detection feedback module 100 and the first terminal of the relay contact K1.

[0060] Fuse F1 is connected in series in the AC input path to blow in case of overcurrent or short circuit faults, cutting off the power supply to the main circuit and protecting the downstream circuits from damage.

[0061] In one embodiment, such as Figure 3 As shown, the power switching circuit 10 also includes a second capacitor C2, and the first end of the AC power supply 20 is connected to the first end of the relay contact K1.

[0062] The first terminal of the second capacitor C2 is connected to the first terminal of the AC power supply 20, and the second terminal of the second capacitor C2 is connected to the second terminal of the AC power supply 20.

[0063] The second capacitor C2 is used to absorb high-frequency interference and transient spikes. Together with the fuse F1, it forms a protection circuit to improve the system's anti-interference capability.

[0064] In one embodiment, such as Figure 3 As shown, the power switching circuit 10 also includes a voltage conversion module 300. The input terminal of the voltage conversion module 300 is connected to the AC power supply 20. The voltage conversion module 300 is used to generate and output a first operating voltage V1 based on the electrical energy provided by the AC power supply 20.

[0065] The voltage conversion module 300 may include an AC-DC conversion circuit based on the AC / DC transformer chip U3, a transformer T1, and a voltage regulator unit, etc., to convert AC power into a stable DC voltage (first operating voltage V1) to power the relay coil L1. The specific value of the first operating voltage V1 can be set according to the rated parameters of the relay. For example, diode D4, capacitor C5, and resistor R14 can be used to implement voltage regulation and filtering functions.

[0066] In some embodiments, the first operating voltage V1 is specifically a 12V voltage.

[0067] In one embodiment, the voltage conversion module 300 is also connected to the detection feedback module 100, and the voltage conversion module 300 is also used to output a second working voltage V2 and a third working voltage V3.

[0068] The second operating voltage V2 and the third operating voltage V3 can power the detection feedback module 100 to ensure its normal operation.

[0069] The second operating voltage V2 and the third operating voltage V3 can be configured according to the requirements of the detection feedback module 100.

[0070] In some embodiments, the main control module 200 further includes a rectifier filter circuit and an optocoupler, and the main control chip U2 is also provided with a level detection terminal.

[0071] The input terminal of the rectifier filter unit is connected to the second terminal of contact K1. The anode of the optocoupler is connected to the output terminal of the rectifier filter unit. The cathode of the optocoupler is grounded. The collector of the optocoupler is grounded. The emitter of the optocoupler is connected to the level detection terminal of the main control chip U2 and the first terminal of the eighth resistor, respectively. The second terminal of the eighth resistor is connected to the third working voltage V3.

[0072] The rectifier and filter unit rectifies and filters the voltage at the second terminal of contact K1 to convert the AC power at the second terminal of contact K1 into DC power, while the optocoupler provides electrical isolation. When no electrical energy flows through contact K1, the voltage at the level detection terminal is the third operating voltage V3; when electrical energy flows through contact K1, the voltage at the level detection terminal is less than the third operating voltage V3.

[0073] When the AC power supply 20 is normal, the main control chip U2 can determine the state of contact K1 based on the voltage at the level detection terminal. Then, based on the time difference between the action time of contact K1 (e.g., the time when the main control chip U2 detects that the voltage at the level detection terminal is lower than the third operating voltage V3) and the action time of the second switching device Q2 (e.g., the time when the main control chip U2 controls the second switching device Q2 to turn on), the output of the corresponding control signal can be corrected. Specifically, when the time difference between the action time of contact K1 and the action time of the second switching device Q2 is detected to be greater than a certain threshold, the main control chip U2 can control the second switching device Q2 to act earlier based on the time difference, so that the actual action time of contact K1 matches the zero-crossing moment of the AC voltage provided by the AC power supply 20.

[0074] Figure 4 A schematic diagram of an electronic device according to an embodiment of this application is shown. For ease of explanation, only the parts related to this embodiment are shown, and the details are as follows: An electronic device 40 includes a power switching circuit 10 as described in any of the above embodiments.

[0075] Specifically, electronic device 40 includes lighting equipment. Load 30 may specifically be a light-emitting device.

[0076] From the above description of the embodiments, those skilled in the art will understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0077] It should be understood that the apparatuses and methods disclosed in the several embodiments provided in this application can be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the division of modules or units is only a logical functional division. In actual implementation, there may be other division methods, such as multiple units or components being combined or integrated into another device. In addition, some features may be omitted or not performed. Furthermore, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, and the indirect coupling or communication connection of devices or units may be electrical, mechanical, or other forms.

[0078] The units described as separate components may or may not be physically separate. A component shown as a unit can be one or more physical units. That is, it can be located in one place or distributed in multiple different locations. Depending on the actual needs, some or all of the units can be selected to achieve the purpose of this solution.

[0079] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit; they can also exist physically separately; or some units can be integrated into one unit while others exist physically separately. The integrated units described above can be implemented in hardware or as software functional units.

[0080] It should be noted that all or part of the above embodiments provided in this application (e.g., part or all of any feature) can be arbitrarily combined or combined with each other.

[0081] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A power switching circuit, characterized in that, include: Relays, detection feedback modules, and main control modules; The first end of the relay contact is used to connect to the AC power supply, the second end of the relay contact is used to connect to the load, the first end of the relay coil is connected to the first operating voltage, and the second end of the relay coil is connected to the first end of the main control module. The input terminal of the detection feedback module is connected to the first terminal of the relay contact, and the output terminal of the detection feedback module is connected to the second terminal of the main control module. The detection feedback module is used to output a feedback signal based on the voltage of the first terminal of the relay contact. The feedback signal is at a first level when the voltage at the first terminal of the relay contact is greater than zero, and at a second level when the voltage at the first terminal of the relay contact is less than zero. The main control module is used to control the connection or disconnection between the second terminal of the relay coil and the ground terminal when the feedback signal undergoes a level shift, according to the control command.

2. The power switching circuit as described in claim 1, characterized in that, The detection feedback module includes a waveform conversion unit and an isolation unit; The input terminal of the waveform conversion unit is connected to the first terminal of the relay contact, the output terminal of the waveform conversion unit is connected to the input terminal of the isolation unit, and the output terminal of the isolation unit is connected to the second terminal of the main control module. The waveform conversion unit is used to convert AC signals into square wave signals.

3. The power switching circuit as described in claim 2, characterized in that, The waveform conversion unit includes: a first capacitor, a first resistor, a second resistor, a third resistor, and a first switching device; The first end of the first capacitor is connected to the first end of the contact of the relay, the second end of the first capacitor is connected to the first end of the first resistor, the second end of the first resistor is connected to the first end of the second resistor and the control end of the first switching device, the second end of the second resistor and the first end of the first switching device are both connected to the second operating voltage, the second end of the first switching device is connected to the first end of the third resistor, and the second end of the third resistor is connected to the input end of the isolation unit.

4. The power switching circuit as described in claim 2, characterized in that, The isolation unit includes an optocoupler and a fourth resistor; The anode of the optocoupler is connected to the output terminal of the waveform conversion unit, the cathode of the optocoupler is grounded, the collector of the optocoupler is grounded, the emitter of the optocoupler is connected to the second terminal of the main control module and the first terminal of the fourth resistor, and the second terminal of the fourth resistor is connected to the third operating voltage.

5. The power switching circuit as described in any one of claims 1 to 4, characterized in that, The main control module includes a main control chip, a fifth resistor, a sixth resistor, and a second switching device; The main control chip is connected to the output terminal of the detection feedback module and the first terminal of the fifth resistor. The second terminal of the fifth resistor is connected to the first terminal of the sixth resistor and the control terminal of the second switching device. The second terminal of the sixth resistor is grounded. The first terminal of the second switching device is connected to the second terminal of the coil of the relay. The second terminal of the second switching device is grounded. The first end of the relay coil is connected to the first operating voltage via a seventh resistor.

6. The power switching circuit as described in any one of claims 2 to 4, characterized in that, The power switching circuit also includes a fuse; The fuse is connected in series between the input terminal of the detection feedback module and the first terminal of the relay contact.

7. The power switching circuit as described in any one of claims 2 to 4, characterized in that, The power switching circuit also includes a second capacitor, and the first end of the AC power supply is connected to the first end of the relay contact. The first terminal of the second capacitor is connected to the first terminal of the AC power supply, and the second terminal of the second capacitor is connected to the second terminal of the AC power supply.

8. The power switching circuit as described in any one of claims 2 to 4, characterized in that, The power switching circuit further includes a voltage conversion module. The input terminal of the voltage conversion module is connected to the AC power supply. The voltage conversion module is used to generate and output the first operating voltage based on the electrical energy provided by the AC power supply.

9. The power switching circuit as described in claim 8, characterized in that, The voltage conversion module is also connected to the detection feedback module, and the voltage conversion module is also used to output a second working voltage and a third working voltage.

10. An electronic device, characterized in that, Includes the power switching circuit as described in any one of claims 1 to 9.

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