A vehicle charging gun detection circuit
By designing a vehicle charging detection circuit, and using a combination of optocouplers and MOSFETs to detect the connection status between charging guns, the safety hazards in the charging process of new energy engineering vehicles are solved, and safe control of the charging process is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ROYPOW TECH CO LTD
- Filing Date
- 2025-07-30
- Publication Date
- 2026-06-30
AI Technical Summary
Existing new energy engineering vehicles lack charging gun detection circuits, which leads to safety hazards during the charging process, such as the risk of accidental vehicle start-up, damage to charging cables, and electric shock accidents.
A vehicle charging detection circuit was designed, including a charging wake-up module, a charging gun detection module, a first step-down module, a second step-down module, and an MCU module. The circuit detects the connection status between the charging gun and the charging port through a combination of optocouplers and MOSFETs, and controls the charging status of the vehicle through the MCU module to prevent the vehicle from starting.
It effectively avoids accidental vehicle starting during charging, prevents damage to charging equipment and electric shock accidents caused by cable pulling, and improves the safety of the charging process.
Smart Images
Figure CN224436570U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of charging gun detection technology, specifically to a vehicle charging gun detection circuit. Background Technology
[0002] Existing new energy engineering vehicles typically lack charging gun detection circuits, which often leads to accidental starting or movement of the vehicle while it is charging due to negligence, posing significant safety hazards. Forcibly moving a vehicle in a charging connection state can easily pull on the charging cable or interface, causing physical damage to the charging equipment, vehicle charging port, and even the vehicle's power system. Furthermore, pulling on the charging cable may cause it to break, short-circuit, or lead to electric shock accidents, posing a direct safety threat to on-site operators. Utility Model Content
[0003] To address the shortcomings of existing technologies, a vehicle charging detection circuit is provided.
[0004] To achieve the above objectives, this utility model provides a vehicle charging detection circuit, including a charging wake-up module, a charging gun detection module, a first buck module, a second buck module, and an MCU module. The charging wake-up module includes an optocoupler U1 and a MOSFET Q1. The optocoupler U1 has a first terminal, a second terminal, a third terminal, and a fourth terminal. The third terminal of the optocoupler U1 is connected to the gate of the MOSFET Q1. The drain of the MOSFET Q1 is connected to the input terminal of the first buck module. The output terminal of the first buck module is connected to both the charging gun detection module and the second buck module. The output terminal of the second buck module is connected to the MCU module. The charging gun detection module includes a first control unit and a second control unit. The first control unit and the second control unit each have a P- terminal, a P-1 terminal, an input terminal, and an output terminal. The P- terminal of the first control unit is connected to the P- terminal of the second control unit. The P-1 terminal of the first control unit is connected to the P-1 terminal of the second control unit. The input terminals of the first control unit and the second control unit are connected to the output terminal of the first buck module. The output terminal of the first control unit is connected to the second control unit. The output terminal of the second control unit is connected to the MCU module.
[0005] According to one embodiment of the present invention, a first control unit includes a first relay and a first isolation unit, and a second control unit includes a second relay and a second isolation unit; the first relay and the second relay respectively have a first connection terminal, a second connection terminal, a third connection terminal, and a fourth connection terminal, and the first isolation unit and the second isolation unit respectively have an input terminal, a first output terminal, and a second output terminal; the input terminal of the first isolation unit and the input terminal of the second isolation unit are connected to the output terminal of the first step-down module, the first output terminal of the first isolation unit is connected to the first output terminal of the second isolation unit, the second output terminal of the first isolation unit is connected to the second connection terminal of the first relay, the first connection terminal of the first relay is connected to the first connection terminal of the second relay, the fourth terminal of the first relay is connected to the output terminal of the first step-down module, and the third connection terminal of the first relay is connected to the fourth connection terminal of the second relay; the second output terminal of the second isolation unit is connected to the second connection terminal of the second relay, and the third connection terminal of the second relay is connected to the MCU module.
[0006] According to one embodiment of the present invention, a charging wake-up signal detection module is also included. The charging wake-up signal detection module includes an optocoupler U3 and a voltage divider unit. The optocoupler U3 has a first end, a second end, a third end, and a fourth end. The first end of the optocoupler U3 is connected to the drain of the MOS transistor Q1. The second end of the optocoupler U3 is connected to the fourth end of the optocoupler U1. The third end of the optocoupler U3 is connected to the output end of the first step-down module. The fourth end of the optocoupler U3 is connected to the voltage divider unit, and the voltage divider unit is connected to the MCU module.
[0007] According to one embodiment of the present invention, a power supply self-holding module is also included. The power supply self-holding module includes an optocoupler U2 and a MOSFET Q2. The optocoupler U2 has a first terminal, a second terminal, a third terminal, and a fourth terminal. The first terminal of the optocoupler U2 is connected to the third terminal of the optocoupler U1 and the gate of the MOSFET, respectively. The second terminal of the optocoupler U2 is connected to the fourth terminal of the optocoupler U1. The third terminal of the optocoupler U2 is connected to the output terminal of the second step-down module. The fourth terminal of the optocoupler U2 is connected to the drain of the MOSFET Q2. The source of the MOSFET Q2 is grounded, and the gate of the MOSFET Q2 is connected to the MCU module.
[0008] According to one embodiment of the present invention, the charging wake-up signal detection module further includes a current-limiting resistor R3, one end of which is connected to the third terminal of the optocoupler U1, and the other end is connected to the gate of the MOS transistor Q1.
[0009] According to one embodiment of the present invention, the first relay and the second relay are normally closed relays.
[0010] According to one embodiment of the present invention, the voltage divider unit includes resistor R5 and resistor R6. One end of resistor R5 is connected to the fourth terminal of optocoupler U3, and the other end is connected to resistor R6 and MCU module respectively. The other end of resistor R6 is grounded.
[0011] According to one embodiment of the present invention, the power supply self-holding module further includes a resistor R4, one end of which is connected to the gate of the MOS transistor Q2, and the other end of which is connected to ground along with the source of the MOS transistor Q2.
[0012] The beneficial effects of this invention are as follows: By setting up a charging wake-up module and a charging gun detection module, when the charging gun is connected to the charging port, the charging gun provides a 12V voltage, causing the optocoupler U1 and MOSFET Q1 to conduct sequentially. The current output from the battery then flows through MOSFET Q1, the first step-down module, and the second step-down module to power the MCU module, enabling the MCU module to operate. After the charging gun is inserted into the charging port, the connection status is detected by checking the switch and closed states of the first and second control units, thus achieving the effect of charging gun connection detection. When the MCU module determines that the charging gun is connected to the charging port, the MCU module prevents the vehicle from starting. This effectively avoids damage to the charging equipment caused by starting the vehicle when the charging gun is connected to the vehicle's charging port, and also effectively prevents electric shock accidents caused by pulling on the charging cable. Attached Figure Description
[0013] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:
[0014] Figure 1 This is a circuit diagram of the vehicle charging gun detection circuit in the embodiment.
[0015] Explanation of reference numerals in the attached figures
[0016] 1. Charging wake-up module; 2. Charging gun detection module; 21. First control unit; 211. First relay; 212. First isolation unit; 22. Second control unit; 221. Second relay; 222. Second isolation unit; 3. First step-down module; 4. Second step-down module; 5. MCU module; 6. Charging wake-up signal detection module; 61. Voltage divider unit; 7. Power supply self-holding module. Detailed Implementation
[0017] The following drawings will disclose several embodiments of this utility model. For clarity, many practical details will be described in the following description. However, it should be understood that these practical details should not be used to limit this utility model. That is, in some embodiments of this utility model, these practical details are not essential. In addition, for the sake of simplicity, some conventional structures and components will be shown in the drawings in a simple schematic manner.
[0018] Furthermore, in this utility model, the use of terms such as "first" and "second" is for descriptive purposes only and does not specifically refer to any order or sequence, nor is it intended to limit the utility model. They are merely used to distinguish components or operations described with the same technical terms and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. If a combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.
[0019] Please refer to Figure 1 , Figure 1This is a circuit diagram of a vehicle charging gun detection circuit. This embodiment provides a vehicle charging gun detection circuit, which includes a charging wake-up module 1, a charging gun detection module 2, a first buck module 3, a second buck module 4, and an MCU module 5. The charging wake-up module 1 includes an optocoupler U1 and a MOSFET Q1. The optocoupler U1 has a first terminal, a second terminal, a third terminal, and a fourth terminal. The first and second terminals of the optocoupler U1 are used to connect to the charging gun, the fourth terminal of the optocoupler U1 is used to connect to the negative terminal of the vehicle battery pack, and the third terminal of the optocoupler U1 is connected to the gate of the MOSFET Q1. The source of the MOSFET Q1 is used to connect to the positive terminal of the vehicle battery pack, and the drain of the MOSFET Q1 is connected to the input terminal of the first buck module 3. The charging wake-up module 1 includes a first control unit 21 and a second control unit 22, which are connected in series. Specifically, the first control unit 21 and the second control unit 22 each have a P- terminal, a P-1 terminal, an input terminal, and an output terminal. The P- terminal of the first control unit 21 is connected to the P terminal of the second control unit 22, and the P-1 terminal of the first control unit 21 is connected to the P-1 terminal of the second control unit 22. The input terminals of the first control unit 21 and the second control unit 22 are both connected to the output terminal of the first step-down module 3. The output terminal of the first control unit 21 is connected to the second control unit 22, and the output terminal of the second control unit 22 is connected to the MCU module 5. In this example, the MCU module 5 has an I / O3 port, and the output of the second control unit 22 is electrically connected to the I / O3 port of the MCU module 5.
[0020] In actual use, the P- terminals of the first control unit 21 and the second control unit 22 are connected to the negative terminal of the vehicle battery pack, and the P-1 terminals of the first control unit 21 and the second control unit 22 are connected to the negative terminal contact point of the charging port. The positive terminal of the battery pack is connected to the negative terminal contact point of the charging port. When the charging gun is inserted into the charging port, the positive output interface of the charging gun is connected to the positive terminal contact point of the charging port, and the negative interface of the charging gun is connected to the negative terminal contact point of the charging port. Thus, after the charging gun is inserted into the charging port, the P- terminals of the first control unit 21 and the second control unit 22 are connected to the P-1 terminals of the first control unit 21 and the second control unit 22, forming a closed circuit. Meanwhile, after the charging gun is inserted into the charging port, it provides a 12V power supply voltage to the first and second terminals of the optocoupler U1, energizing and turning on the optocoupler U1. This causes the gate of the MOSFET Q1 to be at a high level, and the gate-gate voltage (GS) of the MOSFET Q1 to exceed its turn-on threshold, thus turning on the MOSFET Q1. After the MOSFET Q1 turns on, the current output from the positive terminal of the battery passes through the MOSFET Q1 and is input to the first buck module 3. The first buck module 3 steps down the current output from the battery and outputs the stepped-down current to the first control unit 21, the second control unit 22, and the second buck module 4. The second buck module 4 receives the current output from the first buck module 3, steps down the current again, and then sends the current to the MCU module 5 to power the MCU module 5. When the first control unit 21 and the second control unit 22 receive the current output from the first step-down module 3, they are energized and disconnected, causing the output terminal of the second control unit 22 to output a low-level signal. The I / O3 port of the MCU module 5 receives the low-level signal, thus the MCU module 5 determines that the charging gun is connected to the charging port. When the I / O3 port of the MCU module 5 is low, the MCU module 5 switches the vehicle to charging mode. In charging mode, the vehicle cannot be started. Only when the I / O3 port of the MCU module 5 is high, the MCU module 5 switches the vehicle to non-charging mode, in which the vehicle can be started. In this way, the MCU module 5 determines whether the charging gun is inserted into the charging port by judging the high-level or low-level signals sent by the first control unit 21 and the second control unit 22, thus achieving the effect of charging gun connection detection. When the MCU module 5 determines that the charging gun is connected to the charging port, the MCU module 5 controls the vehicle to not start, thus effectively preventing the vehicle from starting when the charging gun is connected to the vehicle's charging port, which could damage the charging equipment, and also effectively preventing electric shock accidents caused by pulling on the charging cable.
[0021] In this example, both the first step-down module 3 and the second step-down module 4 are DC-DC modules. The first step-down module 3 converts the electrical signal output from the battery into a 12V electrical signal output, and the second step-down module 4 converts the electrical signal output from the first step-down module 3 into a 5V electrical signal output to adapt to different voltage requirements.
[0022] By setting up a charging wake-up module 1 and a charging gun detection module 2, when the charging gun is connected to the charging port, the charging gun provides a 12V voltage, causing the optocoupler U1 and MOSFET Q1 to conduct sequentially. The current output from the battery then flows through MOSFET Q1, the first step-down module 3, and the second step-down module 4 to power the MCU module 5, enabling the MCU module 5 to operate. After the charging gun is inserted into the charging port, the connection status is detected by checking the switch and closed states of the first control unit 21 and the second control unit 22. Furthermore, in this embodiment, by setting the first control unit 21 and the second control unit 22 in series, if either the first control unit 21 or the second control unit 22 fails and cannot be disconnected, when the charging gun is connected to the charging port, the other control unit will disconnect upon power-up. At this time, the output of the second control unit 22 will still output a low-level signal to the MCU module 5.
[0023] In this example, the charging wake-up module 1 also includes a current-limiting resistor R3. One end of the current-limiting resistor R3 is connected to the third terminal of the optocoupler U1, and the other end is connected to the gate of the MOSFET Q1. The current-limiting resistor R3 is used to limit the current and prevent excessive current from damaging the MOSFET Q1.
[0024] Furthermore, the charging wake-up module 1 also includes a resistor R2, one end of which is connected to the source of the MOSFET Q1, and the other end of which is connected to the gate of the MOSFET Q1. The resistor R2 is used to provide a bias voltage for the MOSFET Q1.
[0025] Furthermore, the first control unit 21 includes a first relay 211 and a first isolation unit 212, and the second control unit 22 includes a second relay 221 and a second isolation unit 222. The first relay 211 and the second relay 221 each have a first connection terminal, a second connection terminal, a third connection terminal, and a fourth connection terminal. The first isolation unit 212 and the second isolation unit 222 each have an input terminal, a first output terminal, and a second output terminal. The input terminals of the first isolation unit 212 and the second isolation unit 222 are respectively connected to the output terminals of the first step-down module 3. The first output terminal of the first isolation unit 212 serves as the P-1 terminal of the first control unit 21, and is connected to the first output terminal of the second isolation unit 222. The second output terminal of the first isolation unit 212 is connected to the second connection terminal of the first relay 211. The first connection terminal of the first relay 211 serves as the P- terminal of the first control unit 21, the fourth connection terminal of the first relay 211 is connected to the output terminal of the first step-down module 3, and the third connection terminal of the first relay 211 is connected to the fourth connection terminal of the second relay 221. The first output terminal of the second isolation unit 222 serves as the P-1 terminal of the second control unit 22, and the second output terminal of the second isolation unit 222 is connected to the second connection terminal of the second relay 221. The first connection terminal of the second relay 221 serves as the P- terminal of the second control unit 22, and the third connection terminal of the second relay 221 is connected to the I / O3 interface of the MCU module 5. This achieves the interconnection of the first control unit 21 and the second control unit 22.
[0026] In this example, the first relay 211 and the second relay 221 are of the same model, and both are normally closed relays. The first isolation unit 212 and the second isolation unit 222 are both DC-DC modules, and both are of the same model.
[0027] In practical use, the electrical signals output by the first step-down module 3 are input to the first isolation unit 212 and the second isolation unit 222, respectively. The first isolation unit 212 receives the electrical signals output by the first step-down module 3 and provides electrical isolation to the first relay 211, thus providing a stable power supply. The second isolation unit 222 receives the electrical signals output by the first step-down module 3 and provides electrical isolation to the second relay 221, thus providing a stable power supply. By setting up the first relay 211 and the second relay 221 units, when either the first relay 211 or the second relay 221 fails and cannot disconnect, the other relay can still be energized and disconnected after the charging gun is inserted into the charging port, and the third connection terminal of the second relay 221 can still output a low-level signal. Thus, even if one relay fails, the charging gun detection module 22 can still detect whether the charging gun is inserted into the charging port.
[0028] The vehicle charging gun detection circuit in this example also includes a charging wake-up signal detection module 6, which comprises an optocoupler U3 and a voltage divider unit 61. The optocoupler U3 has a first terminal, a second terminal, a third terminal, and a fourth terminal. The first terminal of the optocoupler U3 is connected to the drain of the MOSFET Q1, the second terminal of the optocoupler U3 is connected to the fourth terminal of the optocoupler U1, and the fourth terminal of the optocoupler U3 is connected to one end of the voltage divider unit 61. The other end of the voltage divider unit 61 is grounded, and the voltage divider unit 61 is also connected to the MCU module 5. In this example, the MCU module 5 also has an I / O1 port, and the voltage divider unit 61 is connected to the I / O1 port of the MCU module 5.
[0029] When the charging gun is connected to the charging port, optocoupler U1 and MOSFET Q1 turn on sequentially, energizing optocoupler U3. After optocoupler U3 turns on, its fourth terminal outputs an electrical signal. This signal is then divided by voltage divider unit 61 and input to the I / O1 port of MCU module 5, making the I / O1 port of MCU module 5 high. Thus, by setting up the charging wake-up signal detection module 6, when the charging gun is inserted into the charging port, the module sends a high-level signal, and the I / O1 port of MCU module 5 is high, allowing MCU module 5 to determine that the charging gun is inserted into the charging port.
[0030] Furthermore, the voltage divider unit 61 includes resistors R5 and R6. One end of resistor R5 is connected to the fourth terminal of optocoupler U3, and the other end is connected to resistor R6 and MCU module 5 respectively. The other end of resistor R6 is grounded.
[0031] The vehicle charging gun detection circuit in this example also includes a power supply self-holding module 7, which comprises an optocoupler U2 and a MOSFET Q2. The optocoupler U2 has a first terminal, a second terminal, a third terminal, and a fourth terminal. The first terminal of the optocoupler U2 is connected to the third terminal of the optocoupler U1, the second terminal of the optocoupler U2 is connected to the fourth terminal of the optocoupler U1, and the third terminal of the optocoupler U2 is connected to the output terminal of the second step-down module 4. The fourth terminal of the optocoupler U2 is connected to the drain of the MOSFET Q2. The source of the MOSFET Q2 is grounded, and the drain of the MOSFET Q2 is connected to the MCU module 5. In this example, the MCU module 5 also has an I / O2 interface, which is connected to the gate of the MOSFET Q2.
[0032] Furthermore, the power supply self-holding module 7 also includes a resistor R4, one end of which is connected to the gate of the MOSFET Q2, and the other end is connected to ground along with the source of the MOSFET Q2. Resistor R4 is used to provide a bias voltage for the MOSFET Q2.
[0033] When the charging gun is plugged into the charging port, optocoupler U1 and MOSFET Q2 turn on sequentially, causing optocoupler U3 to turn on, and the I / O1 port of MCU module 5 to be at a high level. When the I / O1 port of MCU module 5 is at a high level, the I / O2 port of MCU module 5 sends a high-level signal to the gate of MOSFET Q2, causing MOSFET Q2 to turn on, thereby turning on optocoupler U2. When optocoupler U2 is on, the gate of MOSFET Q1 remains at a high level, keeping MOSFET Q1 on, and the electrical signal output by the battery powers the circuit. Thus, even if the charging gun is unplugged from the charging port, optocoupler U3 will not turn on, but optocoupler U2 will remain on, keeping MOSFET Q1 on, and the battery's electrical signal can still be output to MCU module 5 to maintain the normal operation of MCU module 5.
[0034] The above description is merely an embodiment of this utility model and is not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this utility model should be included within the scope of the claims of this utility model.
Claims
1. A vehicle charging gun detection circuit, characterized in that, include: The system comprises a charging wake-up module (1), a charging gun detection module (2), a first step-down module (3), a second step-down module (4), and an MCU module (5). The charging wake-up module (1) includes an optocoupler U1 and a MOS transistor Q1. The optocoupler U1 has a first terminal, a second terminal, a third terminal, and a fourth terminal. The third terminal of the optocoupler U1 is connected to the gate of the MOS transistor Q1. The drain of the MOS transistor Q1 is connected to the input terminal of the first step-down module (3). The output terminal of the first step-down module (3) is connected to the charging gun detection module (2) and the second step-down module (4), respectively. The output terminal of the second step-down module (4) is connected to the MCU module (5). The charging gun detection module (2) includes a first control unit. (21) and the second control unit (22), the first control unit (21) and the second control unit (22) respectively have a P- terminal, a P-1 terminal, an input terminal and an output terminal, the P- terminal of the first control unit (21) is connected to the P- terminal of the second control unit (22), the P-1 terminal of the first control unit (21) is connected to the P-1 terminal of the second control unit (22), the input terminal of the first control unit (21) and the input terminal of the second control unit (22) are connected to the output terminal of the first step-down module (3), the output terminal of the first control unit (21) is connected to the second control unit (22), and the output terminal of the second control unit (22) is connected to the MCU module (5).
2. The vehicle charging gun detection circuit according to claim 1, characterized in that, The first control unit (21) includes a first relay (211) and a first isolation unit (212), and the second control unit (22) includes a second relay (221) and a second isolation unit (222); the first relay (211) and the second relay (221) respectively have a first connection terminal, a second connection terminal, a third connection terminal and a fourth connection terminal, and the first isolation unit (212) and the second isolation unit (222) respectively have an input terminal, a first output terminal and a second output terminal; the input terminal of the first isolation unit (212) and the input terminal of the second isolation unit (222) are connected to the output terminal of the first step-down module (3), and the first output terminal of the first isolation unit (212) is connected to the first step-down module (3). The first output terminal of the second isolation unit (222) is connected to the first output terminal of the second isolation unit (212), the second output terminal of the first isolation unit (212) is connected to the second connection terminal of the first relay (211), the first connection terminal of the first relay (211) is connected to the first connection terminal of the second relay (221), the fourth terminal of the first relay (211) is connected to the output terminal of the first step-down module (3), and the third connection terminal of the first relay (211) is connected to the fourth connection terminal of the second relay (221); the second output terminal of the second isolation unit (222) is connected to the second connection terminal of the second relay (221), and the third connection terminal of the second relay (221) is connected to the MCU module (5).
3. The vehicle charging gun detection circuit according to claim 1, characterized in that, It also includes a charging wake-up signal detection module (6), which includes an optocoupler U3 and a voltage divider unit (61). The optocoupler U3 has a first end, a second end, a third end and a fourth end. The first end of the optocoupler U3 is connected to the drain of the MOS transistor Q1. The second end of the optocoupler U3 is connected to the fourth end of the optocoupler U1. The third end of the optocoupler U3 is connected to the output end of the first step-down module (3). The fourth end of the optocoupler U3 is connected to the voltage divider unit (61). The voltage divider unit (61) is connected to the MCU module (5).
4. The vehicle charging gun detection circuit according to claim 1, characterized in that, It also includes a power supply self-holding module (7), which includes an optocoupler U2 and a MOS transistor Q2. The optocoupler U2 has a first end, a second end, a third end and a fourth end. The first end of the optocoupler U2 is connected to the third end of the optocoupler U1 and the gate of the MOS transistor, respectively. The second end of the optocoupler U2 is connected to the fourth end of the optocoupler U1. The third end of the optocoupler U2 is connected to the output terminal of the second step-down module (4). The fourth end of the optocoupler U2 is connected to the drain of the MOS transistor Q2. The source of the MOS transistor Q2 is grounded. The gate of the MOS transistor Q2 is connected to the MCU module (5).
5. The vehicle charging gun detection circuit according to claim 3, characterized in that, The charging wake-up signal detection module (6) also includes a current-limiting resistor R3, one end of which is connected to the third terminal of the optocoupler U1, and the other end is connected to the gate of the MOS transistor Q1.
6. The vehicle charging gun detection circuit according to claim 2, characterized in that, The first relay (211) and the second relay (221) are normally closed relays.
7. The vehicle charging gun detection circuit according to claim 3, characterized in that, The voltage divider unit (61) includes resistors R5 and R6. One end of resistor R5 is connected to the fourth terminal of the optocoupler U3, and the other end is connected to resistor R6 and the MCU module respectively. The other end of resistor R6 is grounded.
8. The vehicle charging gun detection circuit according to claim 4, characterized in that, The power supply self-holding module (7) also includes a resistor R4, one end of which is connected to the gate of the MOS transistor Q2, and the other end of which is connected to ground along with the source of the MOS transistor Q2.