Power switching circuit, power supply circuit and automobile alternating current charging pile

Abstract

The utility model discloses a power supply switching circuit, a power supply circuit and an automobile alternating current charging pile, the power supply switching circuit is applied to the automobile alternating current charging pile, the automobile alternating current charging pile comprises a main control circuit, and the power supply switching circuit comprises a power supply circuit used for outputting a first voltage; the input end of the voltage stabilizing circuit is electrically connected with the output end of the power supply circuit, and the voltage stabilizing circuit is used for carrying out voltage stabilizing processing on the input first voltage and then outputting the first voltage; the input end of the filter circuit is electrically connected with the output end of the voltage stabilizing circuit, the output end of the filter circuit is electrically connected with the power supply input end of the main control circuit, and the filter circuit is used for filtering the second voltage which is output after voltage stabilizing processing and outputting the second voltage to the main control circuit. The utility model aims to improve the temporary power supply capability when the automobile AC charging pile is powered off.

Description

Technical Field

[0001] The utility model relates to the technical field of power management, and in particular to a power switching circuit, a power supply circuit and an automobile AC charging pile. Background Art

[0002] Many existing AC charging piles for cars will not be able to charge the car when the mains power is cut off, and the user will not be notified that the charging pile is currently in a power-off state, and the car will not be able to obtain power. When the user thinks that the car has been charged for several hours and is sufficient for driving, he finds that the car's current power level is not as expected. This will disrupt the user's travel plan and bring a very poor user experience. Therefore, it is particularly important for the charging pile to feedback this information to the user in a timely and stable manner when the mains power is cut off. Utility Model Content

[0003] The main purpose of the utility model is to provide a power switching circuit, aiming to improve the temporary power supply capacity when the AC charging pile of the automobile is powered off.

[0004] To achieve the above-mentioned purpose, the utility model proposes a power switching circuit, which is applied to an automobile AC charging pile. The automobile AC charging pile includes a main control circuit, and the power switching circuit includes:

[0005] a power supply circuit, the power supply circuit being configured to output a first voltage;

[0006] A voltage stabilizing circuit, wherein an input end of the voltage stabilizing circuit is electrically connected to an output end of the power supply circuit, and the voltage stabilizing circuit is used to output a first input voltage after voltage stabilization;

[0007] A filter circuit, wherein the input end of the filter circuit is electrically connected to the output end of the voltage stabilizing circuit, the output end of the filter circuit is electrically connected to the power input end of the main control circuit, and the filter circuit is used to filter the second voltage output after the voltage stabilization process and output it to the main control circuit.

[0008] Preferably, the power supply circuit comprises:

[0009] Power supply battery;

[0010] A capacitor circuit, wherein the input end of the capacitor circuit is electrically connected to the output end of the power supply battery, the output end of the capacitor circuit is electrically connected to the voltage stabilizing circuit, and the capacitor circuit is used to provide instantaneous large current.

[0011] Preferably, the capacitor circuit comprises: a first capacitor and a second capacitor;

[0012] Among them, the first end of the first capacitor is electrically connected to the output end of the battery and the input end of the voltage stabilizing circuit, and the second end is electrically connected to the second end of the second capacitor; the second end of the second capacitor is electrically connected to the output end of the battery, the input end of the voltage stabilizing circuit, and the ground end.

[0013] Preferably, the voltage stabilizing circuit comprises a third capacitor, a first inductor, and a voltage stabilizing chip;

[0014] Among them, the first end of the third capacitor is electrically connected to the output end of the battery, the first end of the first capacitor, the first end of the first inductor, the BAT pin and the EN pin of the voltage stabilizing chip, and the second end is electrically connected to the second end of the second capacitor, the output end of the battery, and the ground terminal; the second end of the first inductor is electrically connected to the SW pin of the voltage stabilizing chip.

[0015] Preferably, the filtering circuit includes a fourth capacitor, a fifth capacitor, and a sixth capacitor;

[0016] Among them, the first end of the fourth capacitor is electrically connected to the OUT pin of the voltage stabilizing chip, the first end of the fifth capacitor, the first end of the sixth capacitor, and the main control circuit, and the second end is electrically connected to the second end of the fifth capacitor, the second end of the sixth capacitor, and the ground end.

[0017] Preferably, the power switching circuit further includes a clamping circuit, an input end of the clamping circuit is electrically connected to an output end of the filter circuit, and the clamping circuit is used to limit the output voltage to below a preset threshold voltage.

[0018] Preferably, the power switching circuit further comprises a prompt circuit, an input end of the prompt circuit is electrically connected to an output end of the voltage stabilizing circuit, and the prompt circuit is used to output a prompt signal when the power switching circuit is in an operating state.

[0019] The utility model also provides a power supply circuit, which includes the power supply switching circuit as described in any one of the above items.

[0020] Preferably, the power supply circuit also includes a voltage conversion circuit, the input end of the voltage conversion circuit is electrically connected to the AC voltage access end, and the output end of the voltage conversion circuit is electrically connected to the input end of the main control circuit; the voltage conversion circuit is used to output the power supply voltage after converting the AC voltage.

[0021] The utility model further provides an automobile AC charging pile, the automobile AC charging pile comprising any one of the power switching circuits described above or any one of the power supply circuits described above; and

[0022] A communication circuit is electrically connected to the main control circuit, and the communication circuit is used to output a communication signal.

[0023] The utility model adopts a power switching circuit, wherein the power switching circuit is applied to the automobile AC charging pile, and the automobile AC charging pile includes a main control circuit; the power switching circuit includes a power circuit, a voltage stabilizing circuit, and a filter circuit. Specifically, when the mains power of the automobile AC charging pile is cut off, the power circuit provides a temporary power supply, outputs a first voltage to the voltage stabilizing circuit, and outputs a second voltage after voltage stabilization by the voltage stabilizing circuit. The second voltage is filtered by the filter circuit and output to the main control circuit, so that the main control circuit is powered and further controls the communication circuit, thereby achieving the technical effect of power outage notification. The power switching circuit enables the automobile AC charging pile to have the ability to temporarily supply power when the mains power supply is disconnected, thereby promptly notifying the user that the current automobile charging is in a disconnected state. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0025] Figure 1 This is a module diagram of an embodiment of a power switching circuit of the utility model;

[0026] Figure 2 It is a structural schematic diagram of an embodiment of a power switching circuit of the utility model;

[0027] Figure 3 It is a structural schematic diagram of an embodiment of a power supply switching circuit of the utility model.

[0028] Description of Figure Numbers:

[0029] Label name Label name 10 Main control circuit C1-C6 First capacitor - sixth capacitor 20 Power Circuit R1-R2 First resistor - second resistor 30 Voltage stabilization circuit D1 Light Emitting Diode 40 Filter circuit D2 Zener diode

[0030] The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0032] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back...) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0033] In addition, the descriptions of "first", "second", etc. in the present utility model are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present utility model.

[0034] Many existing AC charging piles for cars will not be able to charge the car when the mains power is cut off, and the user will not be notified that the charging pile is currently in a power-off state, and the car will not be able to obtain power. When the user thinks that the car has been charged for several hours and is sufficient for driving, he finds that the car's current power level is not as expected. This will disrupt the user's travel plan and bring a very poor user experience. Therefore, it is particularly important for the charging pile to feedback this information to the user in a timely and stable manner when the mains power is cut off.

[0035] Therefore, reference Figure 1 and Figure 2 The utility model proposes a power switching circuit, which is applied to an AC charging pile for an automobile. The AC charging pile for an automobile comprises a main control circuit 10. The power switching circuit comprises:

[0036] A power supply circuit 20, wherein the power supply circuit 20 is used to output a first voltage;

[0037] A voltage stabilizing circuit 30, wherein the input end of the voltage stabilizing circuit 30 is electrically connected to the output end of the power supply circuit 20, and the voltage stabilizing circuit 30 is used to output the input first voltage after voltage stabilization processing;

[0038] The filter circuit 40 has an input end electrically connected to an output end of the voltage stabilizing circuit 30, and an output end of the filter circuit 40 electrically connected to a power input end of the main control circuit 10. The filter circuit 40 is used to filter the second voltage after the voltage stabilization process and output it to the main control circuit 10.

[0039] The main control circuit 10 in the automobile AC charging pile can be implemented by MCU (Microcontroller Unit), DSP (Digital Signal Process), FPGA (Field Programmable Gate Array), SOC (System On Chip), etc.

[0040] In this embodiment, the power supply circuit 20 can be implemented by a lithium battery, a nickel-hydrogen battery, etc. Among them, the battery can be provided with a power input terminal, which is connected to the mains connection terminal of the automobile AC charging pile, and does not output voltage to the outside when there is voltage input at the mains connection terminal, so that the internal power of the battery is always in a saturated state, and temporarily supplies power when the subsequent mains access terminal is disconnected from the power supply. In addition, when there is voltage input at the mains access terminal, the battery will be charged until the battery power is in a saturated state, thereby ensuring that the battery has sufficient power to supply power for subsequent work and output a first voltage. Specifically, the power supply circuit 20 includes: a power supply battery; a capacitor circuit, the input end of the capacitor circuit is electrically connected to the output end of the power supply battery, the output end of the capacitor circuit is electrically connected to the voltage stabilizing circuit 30, and the capacitor circuit is used to provide instantaneous large current. The capacitor circuit and the power supply battery jointly provide power for the circuit, and the capacitor circuit and the power supply battery can be used to have their own advantages and characteristics, so that they play different roles in the circuit. The advantage of the power supply battery is that it can provide a stable voltage, but the disadvantage is that the discharge time is limited, and as the battery is discharged, the voltage will gradually decrease. Capacitor circuits have advantages such as fast charging and discharging, high power density, and long cycle life, but the disadvantage is that the capacity is relatively small and cannot provide large current for a long time. In this case, the combination of capacitor circuits and power supply batteries can provide a balanced power solution. The power supply battery can provide a stable power supply, while the supercapacitor can provide a large current for a short time, such as when starting the circuit or transient load. In this way, the circuit can respond quickly when needed while maintaining a stable working state for a long time.

[0041] Furthermore, the capacitor circuit includes: a first capacitor C1 and a second capacitor C2;

[0042] Among them, the first end of the first capacitor C1 is electrically connected to the output end of the battery and the input end of the voltage stabilizing circuit 30, and the second end is electrically connected to the second end of the second capacitor C2; the second end of the second capacitor C2 is electrically connected to the output end of the battery, the input end of the voltage stabilizing circuit 30, and the ground end.

[0043] In this embodiment, the voltage stabilizing circuit 30 can be implemented by a linear voltage stabilizing circuit 30, a Zener diode voltage stabilizing circuit 30, a switching voltage stabilizing circuit 30, etc. Specifically, the voltage stabilizing circuit 30 includes a third capacitor C3, a first inductor, and a voltage stabilizing chip; wherein the first end of the third capacitor C3 is electrically connected to the output end of the battery, the first end of the first capacitor C1, the first end of the first inductor, the BAT pin and the EN pin of the voltage stabilizing chip, and the second end is electrically connected to the second end of the second capacitor C2, the output end of the battery, and the ground end; the second end of the first inductor is electrically connected to the SW pin of the voltage stabilizing chip. Further, the voltage stabilizing chip can be implemented by a WPN4020H2R2MT linear voltage regulator. Among them, WPN4020H2R2MT is a linear voltage regulator, and its main function is to convert the input voltage into a stable output voltage. In this circuit, it is used as the core component of the power module, responsible for adjusting the input voltage to an output voltage of 5V, that is, the second voltage. The working principle of the linear voltage regulator is to adjust the output voltage by changing the conduction degree of the internal transistor. When the input voltage is higher than the set output voltage, the voltage regulator will reduce the conduction degree of the transistor, thereby reducing the output voltage; conversely, when the input voltage is lower than the set output voltage, the voltage regulator will increase the conduction degree of the transistor and increase the output voltage. This regulation method ensures that the output voltage remains constant and is not affected by input voltage fluctuations. The WPN4020H2R2MT is characterized by low output noise, high efficiency and good linearity. It is often used in situations where a stable power supply is required, such as powering microcontrollers, sensors and other electronic devices. In this circuit, it is used to power the MCU to ensure that the MCU can obtain a stable power supply to ensure its normal operation. In addition, the third capacitor C3 and the first inductor together form an LC oscillation circuit for resonant filtering to assist the voltage regulator chip in working.

[0044] In this embodiment, the filter circuit 40 can be implemented by a capacitor filter circuit 40, an inductor filter circuit 40, etc. Specifically, the filter circuit 40 includes a fourth capacitor C4, a fifth capacitor C5, and a sixth capacitor C6; wherein the first end of the fourth capacitor C4 is electrically connected to the OUT pin of the voltage stabilizing chip, the first end of the fifth capacitor C5, the first end of the sixth capacitor C6, and the main control circuit 10, and the second end is electrically connected to the second end of the fifth capacitor C5, the second end of the sixth capacitor C6, and the ground end. The second voltage output by the voltage stabilizing circuit 30 is filtered and output to the main control circuit 10, so that the main control circuit 10 obtains a stable 5V voltage source.

[0045] When the AC charging pile of the car is powered off, the power supply circuit 20 provides temporary power supply, outputs a first voltage to the voltage stabilizing circuit 30, and outputs a second voltage after voltage stabilization by the voltage stabilizing circuit 30. The second voltage is filtered by the filter circuit 40 and then output to the main control circuit 10, so that the main control circuit 10 is powered and further controls the communication circuit, thereby achieving the technical effect of power failure notification. The power switching circuit enables the AC charging pile of the car to have the ability to temporarily supply power when the main power supply is disconnected, so as to promptly notify the user that the current car charging is in a disconnected state.

[0046] refer to Figure 2 In one embodiment of the utility model, the power switching circuit further includes a clamping circuit, an input end of the clamping circuit is electrically connected to an output end of the filter circuit 40, and the clamping circuit is used to limit the output voltage to below a preset threshold voltage.

[0047] In this embodiment, the clamping circuit can be implemented by a diode clamping circuit, an RC clamping circuit, etc. Specifically, it can be implemented by a voltage stabilizing diode D2. The first voltage output by the power supply circuit 20 is stabilized by the voltage stabilizing circuit 30, and then output by the second voltage, which is filtered by the filter circuit 40. The clamping circuit limits the output voltage after filtering to below the preset threshold voltage, so that the voltage output to the main control circuit 10 is within a safe value, thereby ensuring the power supply safety of the main control circuit 10.

[0048] refer to Figure 2 In one embodiment of the utility model, the power switching circuit also includes a prompt circuit, the input end of the prompt circuit is electrically connected to the output end of the voltage stabilizing circuit 30, and the prompt circuit is used to output a prompt signal when the power switching circuit is in a working state.

[0049] In this embodiment, the prompt circuit can be implemented by an indicator light prompt circuit, a voice prompt circuit, etc. Specifically, it can be implemented by an indicator light prompt circuit. The indicator light prompt circuit includes a first resistor R1, a second resistor R2, and a light emitting diode D1; wherein the first end of the first resistor R1 is electrically connected to the ISET pin of the voltage stabilizing chip, and the second end is electrically connected to the cathode of the light emitting diode D1, the ground terminal, and the PGND pin of the voltage stabilizing chip; the first end of the second resistor R2 is electrically connected to the LED pin of the voltage stabilizing chip, and the second end is electrically connected to the anode of the light emitting diode D1. When the light emitting diode D1 is directly connected between the positive pole of the power supply and the ground, then when the power supply is turned on, the light emitting diode D1 will work and prompt by emitting light. The light emitting diode D1 is connected to the power supply through a resistor, so the light emitting diode D1 will only emit light when the current is large enough. This usually means that the circuit has been properly connected and the power supply has been turned on. Referring to the figure, the light emitting diode D1 is usually used to indicate the working state of the power supply circuit 20, such as whether the power supply circuit 20 is turned on and working. If the light emitting diode D1 is not bright, it may mean that the power supply circuit 20 is not turned on or there is a circuit problem.

[0050] The present invention also proposes a power supply circuit, which includes a power switching circuit as described in any one of the above items. It is worth noting that since the power supply circuit of the present invention is based on the above power switching circuit, the embodiments of the power supply circuit of the present invention include all technical solutions of all embodiments of the above power switching circuit, and the technical effects achieved are also exactly the same, which will not be repeated here.

[0051] refer to Figure 3 In one embodiment of the utility model, the power supply circuit also includes a voltage conversion circuit, the input end of the voltage conversion circuit is electrically connected to the AC voltage access end, and the output end of the voltage conversion circuit is electrically connected to the input end of the main control circuit 10; the voltage conversion circuit is used to convert the AC voltage and then output the power supply voltage.

[0052] In this embodiment, the voltage conversion circuit can be implemented by a rectifier circuit and a DC / DC voltage conversion circuit, that is, an AC / DC voltage converter, according to the actual application scenario. The relationship between the power supply voltage and the voltage required by the load needs to be considered to select the corresponding voltage conversion circuit. Specifically, in this embodiment, the power supply connected to the car AC charging pile is a mains power supply, which is AC power, and the power supply required by the main control circuit 10 and other circuits is a DC power supply. Therefore, the voltage conversion circuit used in this embodiment is an AC / DC voltage conversion circuit, which converts the input AC power into DC power through the AC / DC conversion circuit and outputs it to the power consumption unit.

[0053] In addition, in order to ensure the safety of the voltage conversion circuit when the AC voltage is connected, a protection circuit can be added to the input end of the voltage conversion circuit to improve the safety of the circuit. The protection circuit can be implemented by a current limiting circuit, a fuse, etc. Specifically, taking a fuse as an example, when a circuit fails or is abnormal, the current continues to increase, and the increased current may damage certain important components in the circuit, and may also burn the circuit or even cause a fire. If the fuse is correctly placed in the circuit, the fuse will melt and cut off the current when the current abnormally rises to a certain height and temperature, thereby playing a role in protecting the safe operation of the circuit. By setting a protection circuit, the input AC current is limited to the first current, that is, below the safe current, to improve the safety of the power supply circuit.

[0054] The power supply circuit also includes a temperature detection circuit, which can be implemented by a detection circuit based on a thermistor, such as a resistor voltage divider circuit based on an NTC resistor or an NTC probe, or a resistor voltage divider circuit based on a PTC resistor or a PTC probe. Optionally, the temperature detection circuit can also be implemented by a temperature sensor, such as an infrared temperature sensor, a thermocouple temperature sensor, etc. Among them, there can be multiple temperature detection circuits, and multiple temperature detection circuits can be arranged at different positions in the hook. The main control circuit 10 can determine multiple temperature values ​​according to multiple temperature detection signals, and calculate the actual ambient temperature through a preset temperature algorithm, such as an average value, a weighted calculation, etc., so as to improve the accuracy of the detection of the ambient temperature of the hook. Specifically, the temperature detection circuit uses two groups of NTC resistors, and the two ends of the NTC resistors are respectively connected to the positive pole of the AC input terminal and the negative pole of the AC output terminal, so as to determine whether the current circuit is in an abnormal state through temperature detection. Further, the power supply circuit also includes a voltage stabilizing circuit 30, a filter circuit 40, etc.

[0055] The utility model further provides an automobile AC charging pile, the automobile AC charging pile comprising a power switching circuit as described in any one of the above items or a power supply circuit as described in any one of the above items; and

[0056] A communication circuit, wherein the communication circuit is electrically connected to the main control circuit 10, and the communication circuit is used to output a communication signal.

[0057] It is worth noting that since the automobile AC charging pile of the utility model is based on the above-mentioned power switching circuit or power supply circuit, the embodiments of the automobile AC charging pile of the utility model include all technical solutions of all embodiments of the above-mentioned power switching circuit or power supply circuit, and the technical effects achieved are exactly the same, which will not be repeated here.

[0058] In this embodiment, the communication circuit can be implemented by a wireless communication module, a wired communication module, etc. Among them, the wireless communication module can adopt a wireless communication chip, such as a 4G / 5G communication chip, a WI FI communication chip, a Bluetooth communication chip, a local area network communication chip, etc. The wired communication module 10 can adopt a wired communication chip, such as a CAN communication chip, an SPI communication chip, an I2C communication chip, a LIN communication chip, etc. Specifically, take the wireless communication module as an example. When the AC charging pile of the car stops supplying electricity, the power switching circuit will use the battery and capacitor as a temporary power supply to power the main control circuit 10, etc. The main control circuit 10 can know through the voltage detection circuit that the current power supply is the main power supply or the battery and capacitor. When the main control circuit 10 learns that the current power supply is powered by the battery and capacitor in the power switching circuit, it will send the user through the communication circuit that the current AC charging pile of the car is in a power-off state, so that the user can plan the car in advance and improve the user's charging experience.

[0059] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A power switching circuit, characterized in that: The power switching circuit is applied to an AC charging pile for an automobile. The AC charging pile for an automobile includes a main control circuit. The power switching circuit includes: a power supply circuit, the power supply circuit being configured to output a first voltage; A voltage stabilizing circuit, wherein an input end of the voltage stabilizing circuit is electrically connected to an output end of the power supply circuit, and the voltage stabilizing circuit is used to output a first input voltage after voltage stabilization; A filter circuit, wherein the input end of the filter circuit is electrically connected to the output end of the voltage stabilizing circuit, the output end of the filter circuit is electrically connected to the power input end of the main control circuit, and the filter circuit is used to filter the second voltage output after the voltage stabilization process and then output it to the main control circuit; Wherein, the power supply circuit comprises: Power supply battery; A capacitor circuit, wherein an input end of the capacitor circuit is electrically connected to an output end of the power supply battery, an output end of the capacitor circuit is electrically connected to the voltage stabilizing circuit, and the capacitor circuit is used to provide an instantaneous large current; The capacitor circuit comprises: a first capacitor and a second capacitor; Among them, the first end of the first capacitor is electrically connected to the output end of the battery and the input end of the voltage stabilizing circuit, and the second end is electrically connected to the second end of the second capacitor; the second end of the second capacitor is electrically connected to the output end of the battery, the input end of the voltage stabilizing circuit, and the ground end.

2. The power switching circuit according to claim 1, wherein: The voltage stabilizing circuit includes a third capacitor, a first inductor, and a voltage stabilizing chip; Among them, the first end of the third capacitor is electrically connected to the output end of the battery, the first end of the first capacitor, the first end of the first inductor, the BAT pin and the EN pin of the voltage stabilizing chip, and the second end is electrically connected to the second end of the second capacitor, the output end of the battery, and the ground terminal; the second end of the first inductor is electrically connected to the SW pin of the voltage stabilizing chip.

3. The power switching circuit according to claim 2, wherein: The filtering circuit includes a fourth capacitor, a fifth capacitor, and a sixth capacitor; Among them, the first end of the fourth capacitor is electrically connected to the OUT pin of the voltage stabilizing chip, the first end of the fifth capacitor, the first end of the sixth capacitor, and the main control circuit, and the second end is electrically connected to the second end of the fifth capacitor, the second end of the sixth capacitor, and the ground end.

4. The power switching circuit according to claim 1, wherein: The power switching circuit further includes a clamping circuit, an input end of the clamping circuit is electrically connected to an output end of the filter circuit, and the clamping circuit is used to limit the output voltage to below a preset threshold voltage.

5. The power switching circuit according to claim 1, wherein: The power switching circuit also includes a prompt circuit, an input end of the prompt circuit is electrically connected to an output end of the voltage stabilizing circuit, and the prompt circuit is used to output a prompt signal when the power switching circuit is in a working state.

6. A power supply circuit, characterized in that: The power supply circuit includes a power switching circuit as described in any one of claims 1-5.

7. The power supply circuit according to claim 6, characterized in that: The power supply circuit also includes a voltage conversion circuit, the input end of the voltage conversion circuit is electrically connected to the AC voltage access end, and the output end of the voltage conversion circuit is electrically connected to the input end of the main control circuit; the voltage conversion circuit is used to output the power supply voltage after voltage conversion of the AC voltage.

8. An automobile AC charging pile, characterized in that: The automobile AC charging pile comprises a power switching circuit as described in any one of claims 1 to 5 or a power supply circuit as described in any one of claims 6 to 7; as well as, A communication circuit is electrically connected to the main control circuit, and the communication circuit is used to output a communication signal.

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