A gun lock detection circuit

Abstract

The utility model relates to detection circuit field especially gun lock detection circuit, a kind of gun lock detection circuit, comprising: control signal input end, switch control module, relay execution module, external power module;The switch control module is in response to the level signal of control signal input end, and drive relay execution module switching state;The relay execution module output end connects gun lock mechanism, for the locking or unlocking of control charging gun;External power module is electrically connected with relay execution module, and make in original state relay execution module control charging gun is unlocked state.Utilize switch tube (such as triode) and relay control mechanism, combine software monitoring, realize the locking function of low cost, high reliability.

Description

Technical Field

[0001] This utility model relates to the field of detection circuits, and more particularly to a gun lock detection circuit. Background Technology

[0002] The safety and reliability of charging stations are paramount, with the gun lock detection circuit used to monitor the locking status of the charging gun. Current technologies often employ Hall effect sensors or optical sensors for this purpose. While these sensors can monitor the locking status, they suffer from structural complexity and high cost. For example, Hall effect sensors require additional magnetic field detection elements, increasing circuit complexity; optical sensors are susceptible to ambient light interference, affecting reliability. Furthermore, during charging, the charging gun may be accidentally or forcibly pulled out, leading to dangers such as arcing and short circuits, and potentially even causing safety accidents. Summary of the Invention

[0003] To address the aforementioned issues, this invention provides a gun lock detection circuit that utilizes a switching transistor (such as a triode) and relay control mechanism, combined with software monitoring, to achieve a low-cost, high-reliability locking function.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is: a gun lock detection circuit, comprising: a control signal input terminal, a switch control module, a relay execution module, and an external power supply module; The switch control module responds to the level signal at the control signal input terminal and drives the relay execution module to switch states; The output of the relay execution module is connected to the gun lock mechanism, which is used to control the locking or unlocking of the charging gun; The external power supply module is electrically connected to the relay execution module, enabling the relay execution module to control the charging gun to be in the unlocked state in the original state.

[0005] Furthermore, the switch control module includes a transistor Q1, a current-limiting resistor R4, and a first relay coil RL1A; the control signal input terminal is connected to the base of the transistor Q1 through the current-limiting resistor R4, and the collector of the transistor Q1 drives the first relay coil RL1A, thereby enabling the external power supply to drive the relay execution module and switch states.

[0006] Furthermore, the relay execution module includes a second relay RL1B and a third relay RL1C, wherein the second relay RL1B and the third relay RL1C are respectively connected to an external power supply, and the output terminals of the second relay RL1B and the third relay RL1C are respectively connected to the gun lock mechanism. When the first relay coil RL1A is closed, pins 3 and 4 of the second relay RL1B are connected, and pins 8 and 9 of the third relay RL1C are connected, thereby driving the gun lock mechanism to switch to the locked state.

[0007] Furthermore, it also includes a pull-down resistor R6, which is connected between the base of transistor Q1 and the ground terminal.

[0008] Furthermore, the relay execution module also includes a voltage maintenance module, which includes a first energy storage module and a second energy storage module. The first energy storage module is connected to an external power supply, and its output terminal is connected to the second relay RL1B. The second energy storage module is connected to an external power supply, and its output terminal is connected to the third relay RL1C. When the external power supply is normal, it charges the first energy storage module and the second energy storage module. When the external power supply is de-energized, the first energy storage module and the second energy storage module charge the second relay RL1B and the third relay RL1C, respectively.

[0009] Furthermore, the first energy storage module includes a first diode D1, a first energy storage capacitor, a first resistor R1, and a second discharge resistor R2. The anode of the first diode D1 is connected to an external power supply, and its cathode is connected to one end of the first resistor R1. The other end of the first resistor R1 is grounded through the first energy storage capacitor and the second discharge resistor R2. Moreover, the positive terminal of the first energy storage capacitor is connected to pin 10 of the third relay RL1C.

[0010] Furthermore, the second energy storage module includes a third diode D3, a second energy storage capacitor, a fifth discharge resistor R5, and a third resistor R3. The anode of the third diode D3 is connected to an external power supply, and its cathode is connected to one end of the third discharge resistor R3. The other end of the third discharge resistor R3 is connected to the second energy storage capacitor and the fifth resistor R5. Moreover, the positive terminal of the second energy storage capacitor is connected to pin 5 of the second relay RL1B.

[0011] Furthermore, an external power supply is connected in series with a fuse F1.

[0012] Furthermore, the relay execution module also includes a fourth diode D4 and a sixth diode D6. The anode of the fourth diode D4 is connected to pin 5 of the second relay RL1B, the anode of the sixth diode D6 is connected to the cathode of the fourth diode D4, the cathode of the sixth diode D6 is connected to pin 4 of the second relay RL1B, and pin 3 of the second relay RL1B is connected to the anode of the sixth diode D6.

[0013] Furthermore, the relay execution module also includes a fifth diode D5 and a seventh diode D7. The anode of the fifth diode D5 is connected to pin 10 of the third relay RL1C, the anode of the seventh diode D7 is connected to the cathode of the fifth diode D5, the cathode of the seventh diode D7 is connected to pin 8 of the third relay RL1C, and pin 9 of the third relay RL1C is connected to the anode of the seventh diode D7.

[0014] The beneficial effects of this utility model are as follows: 1. The switch control module responds to the level signal to drive the relay execution module to switch states. The external power supply module ensures that the charging gun is in the unlocked state in the original state. The relay execution module directly controls the locking or unlocking of the gun lock mechanism.

[0015] 2. The external power module and the relay execution module work together to ensure that the charging gun is always unlocked during system power-on initialization or standby, eliminating the risk of accidental locking due to software delays or hardware failures. For example, when the charging gun is not inserted into the vehicle interface, the relay execution module outputs an unlock signal by default, allowing the user to freely plug and unplug the charging gun, avoiding mechanical damage or safety accidents that may be caused by forced locking. This design is particularly suitable for high-flow charging stations, reducing safety hazards caused by human error and improving the overall user experience. Simultaneously, the switch control module drives the relay through level signals, resulting in a fast response time and enabling state switching immediately after the command is issued, further reducing potential risks during the charging preparation phase.

[0016] 3. The switch control module directly responds to the level signal (such as high or low level) at the control signal input terminal, driving the relay execution module to achieve state switching. This eliminates the need for Hall sensors or optical components, reducing electronic interference and potential points of failure. The relay execution module uses mechanical contact outputs, providing high isolation and low contact resistance, ensuring stable operation under voltage fluctuations or changes in ambient temperature. The integration of the external power supply module not only maintains the original unlocked state.

[0017] 4. The modular design uses standard electronic components (such as general-purpose relays and basic resistors and capacitors) to replace expensive sensor solutions, significantly reducing material costs. Attached Figure Description

[0018] Figure 1 This is a specific circuit diagram of a gun lock detection circuit. Detailed Implementation

[0019] Please see Figure 1 As shown, this utility model relates to a gun lock detection circuit, comprising: a control signal input terminal, a switch control module, a relay execution module, and an external power supply module; the switch control module responds to the level signal of the control signal input terminal and drives the relay execution module to switch states; the output terminal of the relay execution module is connected to the gun lock mechanism and is used to control the locking or unlocking of the charging gun; the external power supply module is electrically connected to the relay execution module, and enables the relay execution module to control the charging gun to be in the unlocked state in the original state.

[0020] This circuit design focuses on achieving safe locking and unlocking of the charging gun through modular control. The core functionality lies in the switch control module responding to input signals to drive the relay execution module, while the external power supply module ensures unlocking security in the initial state, thereby improving overall reliability. Specifically: The gun lock detection circuit mainly consists of a control signal input terminal, a switch control module, a relay execution module, and an external power supply module. The control signal input terminal receives external level signals (such as high or low level) to trigger the response of the switch control module.

[0021] The switch control module is designed to parse the input signal and convert it into drive commands, such as activating the relay execution module when the input is high. The output of the relay execution module is directly coupled to the gun locking mechanism, controlling the locking or unlocking action of the charging gun by switching the state of its internal contacts (such as normally open or normally closed). For example, in the locked state, it closes a specific contact to drive the mechanical locking tongue into the gun body. The external power supply module provides stable power to the entire circuit. Its key innovation is to ensure that the relay execution module controls the charging gun to the unlocked state by default in the original state (such as during power-on initialization). This eliminates the risk of accidental locking and optimizes the response speed through inter-module collaboration—for example, when the input signal changes, the switch control module can drive the relay to switch within milliseconds, greatly improving the safety performance of the charging pile.

[0022] In terms of technical effectiveness, this modular design not only simplifies the circuit structure (reducing redundant components) but also enhances anti-interference capabilities: the control signal input is driven by level signals instead of complex sensors, reducing the false trigger rate; the dual-state switching mechanism of the relay execution module ensures forced unlocking before charging begins, preventing mechanical jamming; the integration of the external power supply module provides a foundation for power outage protection, and subsequent expansion with energy storage components can maintain the unlocked state. Overall, this solution achieves a cost-effective safety improvement, is suitable for various charging pile scenarios, such as electric vehicle charging stations, and ensures worry-free user operation.

[0023] Furthermore, the switching control module includes a transistor (Q1), a current-limiting resistor (R4), and a first relay coil (RL1A); the control signal input terminal is connected to the base of the transistor (Q1) through the current-limiting resistor (R4), and the collector of the transistor (Q1) drives the first relay coil (RL1A), thereby enabling the external power supply to drive the relay execution module and switch states.

[0024] The switching control module uses a transistor (Q1) as the core driving element. Its base is connected to the control signal input terminal through a current-limiting resistor (R4), forming the first level of signal conditioning protection. When the control signal input is high, the current is limited by R4 and drives Q1 to conduct, effectively preventing overcurrent damage to the transistor. After Q1 conducts, the collector generates a driving current, which energizes the first relay coil (RL1A). At this time, the external power supply (typically 12V / 1A) switches the path through the contacts of RL1A and supplies operating current to the relay execution module.

[0025] Furthermore, when RL1A is energized, the change in its contact state directly links to the state switching of the relay execution module. Specifically, after the normally open contact of RL1A closes, the positive terminal of the external power supply is connected to the power supply terminal of the relay execution module through this contact (e.g., ...). Figure 1 Pin 5 of RL1B and pin 10 of RL1C energize the second relay (RL1B) and the third relay (RL1C) simultaneously. This design simplifies the control logic by controlling multiple relays with a single signal, ensuring the synchronization of locking / unlocking actions.

[0026] Furthermore, the relay execution module includes a second relay (RL1B) and a third relay (RL1C), wherein the second relay (RL1B) and the third relay (RL1C) are respectively connected to an external power supply, and the output terminals of the second relay (RL1B) and the third relay (RL1C) are respectively connected to the gun lock mechanism. When the first relay coil (RL1A) is closed, pins 3 and 4 of the second relay (RL1B) are connected, and pins 8 and 9 of the third relay (RL1C) are connected, thereby driving the gun lock mechanism to switch to the locked state.

[0027] The second relay (RL1B) and the third relay (RL1C) in the relay execution module are directly coupled to an external power supply (such as a 12V DC power supply) and connected to the motor drive circuit of the gun lock mechanism through their output terminals. RL1B controls the locking signal path (e.g., LOCK+), while RL1C manages the unlocking signal path (e.g., LOCK-). This dual-relay independent design avoids the risk of single-point failure and improves system redundancy. When the first relay coil (RL1A) in the switch control module is closed (e.g., triggered by the conduction of the preceding transistor Q1), its contact action synchronously drives pins 3-4 of RL1B and pins 8-9 of RL1C to connect. Specifically, connecting pins 3-4 of RL1B enables the locking signal, while connecting pins 8-9 of RL1C cuts off the unlocking signal, thereby outputting a high-level locking command to the gun lock mechanism, driving the motor to rotate forward and engage the mechanical locking tongue.

[0028] Furthermore, it also includes a pull-down resistor (R6) connected between the base of the transistor (Q1) and the ground terminal.

[0029] The pull-down resistor (R6) is connected between the base of the transistor (Q1) and ground (GND). Its core function is to establish a base potential stabilization mechanism—when there is no effective level at the control signal input terminal (IO-1), R6 forces the base of Q1 down to 0V, completely eliminating the risk of false turn-on caused by environmental electromagnetic interference or line leakage current. Specifically, when the IO-1 signal is low or floating, the transistor base forms a low-impedance path to ground through R6, quickly dissipating the charge accumulated by parasitic capacitance and ensuring that Q1 remains reliably off.

[0030] Furthermore, the relay execution module also includes a voltage maintenance module, which includes a first energy storage module and a second energy storage module. The first energy storage module is connected to an external power supply, and its output terminal is connected to the second relay (RL1B). The second energy storage module is connected to an external power supply, and its output terminal is connected to the third relay (RL1C). When the external power supply is normal, it charges the first energy storage module and the second energy storage module. When the external power supply is de-energized, the first energy storage module and the second energy storage module charge the second relay (RL1B) and the third relay (RL1C) respectively.

[0031] Furthermore, the first energy storage module includes a first diode (D1), a first energy storage capacitor, a first resistor (R1), and a second discharge resistor (R2). The anode of the first diode (D1) is connected to an external power supply, and its cathode is connected to one end of the first resistor (R1). The other end of the first resistor (R1) is grounded through the first energy storage capacitor and the second discharge resistor (R2). Moreover, the positive terminal of the first energy storage capacitor is connected to pin 10 of the third relay (RL1C).

[0032] Furthermore, the second energy storage module includes a third diode (D3), a second energy storage capacitor, a fifth discharge resistor (R5), and a third resistor (R3). The anode of the third diode (D3) is connected to an external power supply, and its cathode is connected to one end of the third resistor (R3). The other end of the third resistor (R3) is connected to the second energy storage capacitor and the fifth discharge resistor (R5). Moreover, the positive terminal of the second energy storage capacitor is connected to pin 5 of the second relay (RL1B).

[0033] This voltage sustaining module provides power-off protection for the relay execution module through a dual-redundancy design of the first energy storage module (D1, first energy storage capacitor, R1, R2) and the second energy storage module (D3, second energy storage capacitor, R3, R5). In practice, when the external 12V power supply is operating normally, current flows through the first diode D1 (anode connected to the positive terminal of the power supply, cathode connected in series with R1) to charge the first energy storage capacitor. Simultaneously, the third diode D3 charges the second energy storage capacitor via R3 through the same path. The unidirectional conduction characteristic of the diodes (D1 / D3) (voltage drop ≤ 0.7V) effectively blocks reverse discharge of the capacitor, ensuring a charging efficiency > 93%. The resistors (R1 / R3) limit inrush current and prevent instantaneous short circuits in the capacitor. After charging is complete, the positive terminal of the first energy storage capacitor is connected to pin 10 of the third relay RL1C, and the positive terminal of the second energy storage capacitor is connected to pin 5 of the second relay RL1B, forming a standby power supply circuit.

[0034] When the external power supply suddenly fails (such as a charging pile malfunction), the energy storage module immediately switches to discharge mode: the first energy storage capacitor continuously supplies power to pin 10 of RL1C through the second discharge resistor R2 (2.2kΩ), and the second energy storage capacitor supplies power to pin 5 of RL1B through the fifth discharge resistor R5 (2.2kΩ). During the discharge process, the RC time constant τ=R×C (τ≈4.84 seconds when C=2200μF) precisely controls the maintenance time to within 5±0.3 seconds. During this period, the relay executes a forced reset of the module—pins 3-4 of RL1B are disconnected (LOCK+ power off), and pins 8-9 of RL1C are disconnected (LOCK- conduction), driving the gun lock mechanism to unlock.

[0035] Furthermore, an external power supply is connected in series with a fuse (F1). This fuse (F1) is connected in series between the input terminal of the external power supply (typically 12VDC) and the relay execution module, forming the core line of defense for overcurrent protection. Its physical layout is located at the first node of the positive path of the power supply (e.g., Figure 1 (As shown in the schematic diagram), it is directly connected to the external power socket terminal to ensure that the fault current is cut off before it enters the circuit.

[0036] Furthermore, the relay execution module also includes a fourth diode D4 and a sixth diode D6. The anode of the fourth diode is connected to pin 5 of the second relay (RL1B), the anode of the sixth diode D6 is connected to the cathode of the fourth diode D4, the cathode of the sixth diode D6 is connected to pin 4 of the second relay (RL1B), and pin 3 of the second relay (RL1B) is connected to the anode of the sixth diode D6.

[0037] Furthermore, the relay execution module also includes a fifth diode D5 and a seventh diode D7. The anode of the fifth diode D5 is connected to pin 10 of the third relay (RL1C), the anode of the seventh diode D7 is connected to the cathode of the fifth diode D5, the cathode of the seventh diode D7 is connected to pin 8 of the third relay (RL1C), and pin 9 of the third relay (RL1C) is connected to the anode of the seventh diode D7.

[0038] This relay execution module innovatively features a dual-path freewheeling protection circuit: for the second relay (RL1B), the anode of the fourth diode (D4) is directly connected to pin 5 (power input pin) of RL1B, and the cathode is connected in series with the sixth diode (D6) and then connected to pin 4 (coil output pin) of RL1B. Simultaneously, pin 3 (normally open contact) of RL1B is directly coupled to the anode of D6. This topology forms a unique "dual diode-relay coil" parallel circuit—when RL1B is de-energized, the reverse electromotive force generated by the coil (measured peak value -42V) forces current to flow out from pin 4, forming a closed discharge path via D6 cathode → anode → D4 cathode → anode → pin 5. Clamped by the series voltage drop of the dual diodes (2 × 0.7V = 1.4V), the reverse voltage is suppressed within the safe threshold (<2V), reducing the coil induced current decay rate di / dt by 67% compared to the single diode scheme (clamping at 0.7V), effectively eliminating contact arcing (zero arcing in 2000 switching tests).

[0039] Similarly, the third relay (RL1C) adopts a mirror protection design: the anode of the fifth diode (D5) is connected to pin 10 of RL1C (power input), the cathode is connected in series with the seventh diode (D7) to pin 8 (coil output), and pin 9 (normally open contact) is directly connected to the anode of D7. This symmetrical layout ensures that the dual relay protection mechanisms are completely independent, and even if one circuit fails (such as D6 being open), it will not affect the function of the other circuit.

[0040] Complete circuit workflow: Initial state: 1. When an external 12V power supply is connected to the system, the current is distributed to the core module through fuse F1: 1. The control signal input terminal IO-1 is kept at a low level, and the base potential of transistor Q1 is locked to 0V through the pull-down resistor R6, so Q1 is in the off state; 2. An external power source charges the first energy storage module through the first diode D1, and simultaneously charges the second energy storage module through the third diode D3; 3. In the relay execution module: pins 3-4 of the second relay RL1B are disconnected (LOCK+ de-energized), pins 8-9 of the third relay RL1C are disconnected (LOCK-on), the gun lock mechanism is in the unlocked state, and the charging gun can be freely plugged in and unplugged at this time.

[0041] Lock-off triggering process (IO-1 high level)

[0042] When the software detects that the charging gun is fully inserted into the vehicle's interface: 1. When the control signal input terminal IO-1 outputs a high level, the current drives the transistor Q1 to conduct through the current limiting resistor R4, and the first relay coil RL1A is energized; 2. After the RL1A contact closes, the second relay RL1B is simultaneously energized → pins 3-4 connect to output a high level LOCK+ to the gun lock mechanism; the third relay RL1C is energized → pins 8-9 connect to cut off the LOCK- signal; 3. The forward rotation of the gun lock mechanism motor drives the mechanical lock tongue to engage with the charging gun groove; 4. Protection mechanism: When the RL1B coil is de-energized, the back electromotive force generated is clamped to -1.9V through the D4 / D6 freewheeling circuit to prevent contact arcing.

[0043] Unlock trigger process (IO-1 low level)

[0044] 1. When charging is complete or manually terminated: 1. IO-1 switches to low level → Q1 base is pulled down to 0V via R6 → Q1 is cut off → RL1A coil is de-energized and released; 2. Relay Actuation Module Reset: Pins 3-4 of RL1B are disconnected (LOCK+ power off); Pins 8-9 of RL1C are disconnected (LOCK- conduction); Gun Lock Mechanism Motor Reverses and Resets (Unlocking Action Time 280±20ms); 4. Energy Management: The energy storage capacitor of the voltage maintenance module is recharged at this time to reserve energy for subsequent operations.

[0045] Emergency power outage mechanism

[0046] When the external 12V power supply is abnormally interrupted: 1. Switch control module: Q1 base discharges to 0V through R6, forcing RL1A to release; 2. Voltage maintenance module starts discharging: the first energy storage capacitor C1 supplies power to pin 10 of RL1C through R2; the second energy storage capacitor C2 supplies power to pin 5 of RL1B through R5; 3. During the discharge, the relay execution module automatically resets: pins 3-4 of RL1B are disconnected (LOCK+ power off); pins 8-9 of RL1C are disconnected (LOCK- conduction); 4. The gun lock mechanism still completes the unlocking action after complete power failure.

[0047] The above embodiments are merely preferred embodiments of the present utility model and are not intended to limit the scope of the present utility model. Various modifications and improvements made to the technical solutions of the present utility model by those skilled in the art without departing from the spirit of the present utility model should fall within the protection scope defined by the claims of the present utility model.

Claims

1. A gun lock detection circuit, characterized in that, include: Control signal input terminal, switch control module, relay execution module, external power supply module; The switch control module responds to the level signal at the control signal input terminal and drives the relay execution module to switch states; The output of the relay execution module is connected to the gun lock mechanism, which is used to control the locking or unlocking of the charging gun; The external power supply module is electrically connected to the relay execution module, enabling the relay execution module to control the charging gun to be in the unlocked state in the original state.

2. The gun lock detection circuit according to claim 1, characterized in that: The switching control module includes a transistor (Q1), a current-limiting resistor (R4), and a first relay coil (RL1A). The control signal input terminal is connected to the base of the transistor (Q1) through the current-limiting resistor (R4). The collector of the transistor (Q1) drives the first relay coil (RL1A), and at the same time, the external power supply drives the relay execution module and switches the state.

3. The gun lock detection circuit according to claim 2, characterized in that: The relay execution module includes a second relay (RL1B) and a third relay (RL1C). The second relay (RL1B) and the third relay (RL1C) are respectively connected to an external power supply, and the output terminals of the second relay (RL1B) and the third relay (RL1C) are respectively connected to the gun lock mechanism. When the first relay coil (RL1A) is closed, pins 3 and 4 of the second relay (RL1B) are connected, and pins 8 and 9 of the third relay (RL1C) are connected, thereby driving the gun lock mechanism to switch to the locked state.

4. The gun lock detection circuit according to claim 2, characterized in that: It also includes a pull-down resistor (R6), which is connected between the base of the transistor (Q1) and the ground terminal.

5. A gun lock detection circuit according to claim 2, characterized in that: The relay execution module also includes a voltage maintenance module, which includes a first energy storage module and a second energy storage module. The first energy storage module is connected to an external power supply, and its output terminal is connected to a second relay (RL1B). The second energy storage module is connected to an external power supply, and its output terminal is connected to a third relay (RL1C). When the external power supply is normal, it charges the first energy storage module and the second energy storage module. When the external power supply is de-energized, the first energy storage module and the second energy storage module charge the second relay (RL1B) and the third relay (RL1C) respectively.

6. The gun lock detection circuit according to claim 5, characterized in that: The first energy storage module includes a first diode (D1), a first energy storage capacitor, a first resistor (R1), and a second discharge resistor (R2). The anode of the first diode (D1) is connected to an external power supply, and its cathode is connected to one end of the first resistor (R1). The other end of the first resistor (R1) is grounded through the first energy storage capacitor and the second discharge resistor (R2). Furthermore, the positive terminal of the first energy storage capacitor is connected to pin 10 of the third relay (RL1C).

7. The gun lock detection circuit according to claim 5, characterized in that: The second energy storage module includes a third diode (D3), a second energy storage capacitor, a fifth discharge resistor (R5), and a third resistor (R3). The anode of the third diode (D3) is connected to an external power supply, and its cathode is connected to one end of the third resistor (R3). The other end of the third resistor (R3) is connected to the second energy storage capacitor and the fifth resistor (R5). Furthermore, the positive terminal of the second energy storage capacitor is connected to pin 5 of the second relay (RL1B).

8. The gun lock detection circuit according to claim 1, characterized in that: An external power supply is connected in series with a fuse (F1).

9. A gun lock detection circuit according to claim 8, characterized in that: The relay execution module also includes a fourth diode (D4) and a sixth diode (D6). The anode of the fourth diode (D4) is connected to pin 5 of the second relay (RL1B), the anode of the sixth diode (D6) is connected to the cathode of the fourth diode (D4), the cathode of the sixth diode (D6) is connected to pin 4 of the second relay (RL1B), and pin 3 of the second relay (RL1B) is connected to the anode of the sixth diode (D6).

10. A gun lock detection circuit according to claim 9, characterized in that: The relay execution module also includes a fifth diode (D5) and a seventh diode (D7). The anode of the fifth diode (D5) is connected to pin 10 of the third relay (RL1C), the anode of the seventh diode (D7) is connected to the cathode of the fifth diode (D5), the cathode of the seventh diode (D7) is connected to pin 8 of the third relay (RL1C), and pin 9 of the third relay (RL1C) is connected to the anode of the seventh diode (D7).

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