Charging circuit and charging pile

Abstract

The utility model discloses a charging circuit and a charging pile in the technical field of charging control, the charging circuit comprises a transmission unit and relay units, the transmission unit is used for receiving a charging or stopping signal output by a charging control module and transmitting the signal to the relay units connected in series; and the relay unit is used for controlling the on-off of the charging line through a relay according to the received signal transmitted by the transmission unit. According to the utility model, charging is realized by adopting a simple charging circuit structure, and a good economic effect is achieved.

Description

Technical Field

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

[0002] With the government's support for new energy vehicle policies, the "New Energy Vehicle Industry Development Plan (2021-2035)" not only sets long-term development goals but also clarifies specific paths in areas such as technological innovation, infrastructure construction, and market application promotion, providing policy guarantees for the sustainable and healthy development of the new energy vehicle industry. Meanwhile, the introduction of the "dual-carbon" strategy (i.e., carbon peaking and carbon neutrality) further strengthens the urgency of reducing carbon emissions and promoting green transformation. As one of the key areas for achieving this goal, the market growth of new energy vehicles has been strongly driven by policies, and the new energy vehicle market has entered a period of rapid growth.

[0003] With the rapid growth of new energy vehicle ownership, exceeding 120 million vehicles as of February 2025, the improvement of charging infrastructure is a crucial foundation for the development of new energy vehicles. Increasing the number of public charging piles and optimizing the vehicle-to-pile ratio can effectively alleviate "range anxiety" for electric vehicle users and improve the convenience of using electric vehicles. Joint investment by the government and enterprises is accelerating the deployment of charging stations (piles), especially in key areas such as highway service areas, urban commercial districts, and residential communities, making charging services more widespread and convenient.

[0004] Therefore, the economic efficiency, performance stability, and safety of charging infrastructure are directly related to the future promotion of electric vehicles. However, current technologies often employ multiple logic circuits combined with switching circuits to form charging circuits, resulting in complex structures and significant heat generation during prolonged charging. Utility Model Content

[0005] The purpose of this utility model is to provide a charging circuit and a charging pile, which achieves charging using a simple charging circuit structure and has good economic benefits.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0007] In a first aspect, this utility model provides a charging circuit, including a transmission unit and a relay unit. The transmission unit is used to receive a charging or stopping signal output by a charging control module and transmit the signal to a relay unit connected in series. The relay unit is used to control the on / off state of the charging cable through a relay according to the signal transmitted by the transmission unit.

[0008] The aforementioned charging circuit includes a transmission unit comprising resistors R1, R2, and R3, an NPN transistor Q1, and a P-channel MOSFET Q2. One end of resistor R1 is connected to the charging signal output terminal, and the other end of resistor R1 is connected to the base of NPN transistor Q1. The emitter of NPN transistor Q1 is grounded. The collector of NPN transistor Q1 is connected to one end of resistor R2, and the other end of resistor R2 is connected to the gate of P-channel MOSFET Q2. Resistor R3 is connected in parallel between the gate and source of P-channel MOSFET Q2. The source of P-channel MOSFET Q2 is connected to the relay coil operating voltage +V. The drain of P-channel MOSFET Q2 is connected to one end of a relay unit, and the other end of the relay unit is grounded. The charging signal output terminal is the port for the charging control module to output charging or stop signals. The relay unit controls the on / off state of the charging cable through a relay.

[0009] The aforementioned charging circuit also includes a fast start unit, which includes a resistor R4 and an electrolytic capacitor C1. The resistor R4 and the electrolytic capacitor are connected in parallel between the drain of the P-channel MOSFET Q2 and the relay unit. The positive terminal of the electrolytic capacitor C1 is connected to the drain of the MOSFET.

[0010] In the aforementioned charging circuit, the relay unit includes a diode D1 and a relay; the relay includes a coil pin and a contact pin, the coil pin includes a positive terminal and a negative terminal, and the contact pin controls the on / off state of the charging cable; the positive terminal of the coil is connected to the negative terminal of the electrolytic capacitor C1, and the negative terminal of the coil is grounded; the positive and negative terminals of the diode D1 are connected in parallel with the positive and negative terminals of the coil in opposite directions.

[0011] In the aforementioned charging circuit, when the charging cable includes a neutral wire and a live wire, the relays include relay K1 and relay K2, with the positive and negative terminals of the coils of relay K1 and relay K2 connected in parallel in the same direction; the contact pins of relay K1 and relay K2 respectively control the on / off state of the neutral wire and the live wire.

[0012] The aforementioned charging circuit also includes an emergency stop unit, which is connected in series between the transmission unit and ground or between the relay unit and ground.

[0013] The aforementioned charging circuit also includes an emergency stop unit, which is connected in series between the relay unit and ground. The emergency stop unit includes an emergency stop switch X1. The emergency stop switch X1 includes a control pin and a ground pin. The control pin is connected to the relay unit, and the ground pin is grounded. The control pin and the ground pin are normally closed. When the emergency stop switch is pressed, the control pin and the ground pin are open.

[0014] The aforementioned charging circuit also includes an emergency stop unit that includes a fuse R5, which is connected in series between the grounding pin of the emergency stop switch X1 and ground.

[0015] The aforementioned charging circuit, including the emergency stop unit, further comprises a PNP transistor Q3, resistors R6 and R7; the control pin is connected to the base of the PNP transistor Q3, the collector of the PNP transistor Q3 is connected to ground via resistor R6, the emitter of the PNP transistor Q3 is connected to one end of resistor R7 and the emergency stop signal output terminal, and the other end of resistor R7 is connected to the power supply voltage VCC of the charging control module, wherein the power supply voltage VCC of the charging control module is less than the operating voltage +V of the relay coil.

[0016] Secondly, this utility model provides a charging pile, a charging control module, and a charging circuit as described in any one of the first aspects, wherein the charging signal output terminal of the charging control module is connected to one end of a resistor R1.

[0017] Beneficial effects:

[0018] Compared with the prior art, the present invention has the following advantages and advancements:

[0019] The charging circuit of this invention is composed of a transmission unit and a relay unit, and uses a simple charging circuit structure to achieve charging, which has good economic benefits.

[0020] The charging circuit of this invention does not require complex logic gate circuits combined with switching circuits. The circuit consisting of three resistors, one transistor, one MOSFET and a relay unit can realize charging control. It has a simple structure, low cost, is easy to manufacture and has good economic benefits.

[0021] This invention also incorporates a parallel resistor and an electrolytic capacitor into the charging circuit. By utilizing the principle that the voltage of the electrolytic capacitor does not change abruptly, the relay obtains sufficient starting current when charging begins. During continuous charging, once the electrolytic capacitor is fully charged, the resistor's voltage division and current limiting effect reduces the current flowing through the relay. This allows the relay to maintain its engaged state with a holding current lower than the starting current, improving the relay's heat generation during prolonged use, reducing its temperature, and enhancing its operational stability.

[0022] The relay unit of the charging circuit of this utility model is a combination design of diode and relay. The addition of diode eliminates the influence of back electromotive force when the relay coil is de-energized. The number of relays connected in parallel in the relay unit can be adaptively adjusted according to the change of the number of charging lines.

[0023] The addition of the emergency stop unit in this invention further enhances the charging safety of the charging circuit. In addition to manual emergency stop, the emergency stop unit is also equipped with overcurrent protection and emergency stop signal output. In the event of overcurrent, it automatically disconnects the circuit, stops charging, and outputs an emergency stop signal to the charging control module, enabling the charging control module to output a stop signal in a timely manner. In the event of manual emergency stop, the charging circuit stops charging and sends an emergency stop signal to the charging control module, enabling the charging control module to output a stop signal in a timely manner. The dual stop of the upstream and downstream of the relay unit further enhances the safety of the entire circuit. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of a circuit structure for the charging circuit of this utility model; Detailed Implementation

[0025] The technical solutions of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this utility model or its application or use.

[0026] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used to explain the relative positional relationship and movement between components in a specific posture. If the specific posture changes, the directional indication will also change accordingly. These terms are used only for the convenience of describing this utility model and for simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0027] Furthermore, in the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0028] Example 1

[0029] This embodiment describes a charging circuit, including a transmission unit and a relay unit.

[0030] The transmission unit is used to receive the charging or stop signal output by the charging control module and transmit the signal to the relay unit connected in series; the transmission circuit includes an NPN transistor Q1, a P-channel MOSFET Q2 and multiple resistors;

[0031] The relay unit is used to control the on / off state of the charging cable by means of a relay based on the signal transmitted by the receiving and transmitting unit.

[0032] like Figure 1 As shown, the transmission unit includes resistors R1, R2, and R3, an NPN transistor Q1, a P-channel MOSFET Q2, and a relay unit. One end of resistor R1 is connected to the charging signal output terminal, and the other end of resistor R1 is connected to the base of NPN transistor Q1. The emitter of NPN transistor Q1 is grounded. The collector of NPN transistor Q1 is connected to one end of resistor R2, and the other end of resistor R2 is connected to the gate of P-channel MOSFET Q2. Resistor R3 is connected in parallel between the gate and source of P-channel MOSFET Q2. The source of P-channel MOSFET Q2 is connected to the relay coil operating voltage +V. The drain of P-channel MOSFET Q2 is connected to one end of the relay unit, and the other end of the relay unit is grounded. The charging signal output terminal is the port for the charging control module to output charging or stop signals. The relay unit controls the on / off state of the charging line through a relay.

[0033] The charging circuit in this embodiment does not require complex logic gate circuits combined with switching circuits. The circuit consisting of three resistors, one transistor, one MOSFET and a relay unit can realize charging control. It has a simple structure, low cost, is easy to manufacture, and has good economic benefits.

[0034] To improve the heat generation of the relay unit during long-term charging, the charging circuit of this embodiment also includes a fast start unit. The fast start unit includes a resistor R4 and an electrolytic capacitor C1. The resistor R4 and the electrolytic capacitor are connected in parallel between the drain of the P-channel MOSFET Q2 and the relay unit. The positive terminal of the electrolytic capacitor C1 is connected to the drain of the MOSFET.

[0035] The starting current of a relay is typically higher than its holding current during continuous operation. This is because when a relay starts, it needs to overcome initial resistance—that is, overcome the spring force and the air gap in the magnetic circuit—to establish a magnetic field. Once the relay is engaged, maintaining the engaged state only requires maintaining the magnetic field, thus requiring a smaller current. In existing charging circuits, only sufficient starting current is considered, continuously supplying the relay with a current equal to the starting current, neglecting the relay's heating and heat loss during prolonged use.

[0036] In this embodiment, a parallel resistor R4 and an electrolytic capacitor C1 are added to the simplified charging circuit. When the electrolytic capacitor C1 receives the drain current and voltage from the P-channel MOSFET Q2, due to the principle of voltage non-sudden change, the received instantaneous voltage is applied to the relay unit, allowing the relay unit to receive sufficient starting current for rapid start-up. During continuous charging, the P-channel MOSFET Q2 remains on, and the electrolytic capacitor C1 completes charging. At this time, the drain current of the P-channel MOSFET Q2 is transmitted to the relay unit after being current-limited by the resistor R4, supplying the relay unit with sufficient protection current. The protection current is less than the starting current. Compared to supplying the starting current for a long time, this embodiment supplies the protection current during long-term charging, improving the heat generation of the charger unit during long-term charging and reducing heat loss.

[0037] like Figure 1 As shown, the relay unit in this embodiment includes a diode D1 and a relay; the relay includes a coil pin and a contact pin, the coil pin includes a coil positive terminal and a coil negative terminal, and the contact pin controls the on / off state of the charging cable; the coil positive terminal is connected to the negative terminal of the electrolytic capacitor C1, and the coil negative terminal is grounded; the positive and negative terminals of the diode D1 are connected in parallel with the positive and negative terminals of the coil in opposite directions.

[0038] When the relay coil is energized, diode D1 is in reverse cutoff state, which does not affect the normal operation of the circuit.

[0039] When the relay coil is de-energized, the back electromotive force generated by the coil will cause the diode D1 to conduct in the forward direction, forming a closed circuit. The energy of the back electromotive force is dissipated in the coil and diode in the form of current, protecting the circuit from damage caused by the back electromotive force, while reducing electromagnetic interference and improving charging stability.

[0040] When there is only one charging cable, one relay is used to control the on / off state of the charging cable. When there are two charging cables, two relays can be used to control the on / off state of the two charging cables respectively, or one relay can be used to control the on / off state of the two charging cables simultaneously. And so on, the number of relays connected in parallel in the relay unit can be adjusted adaptively according to the number of charging cables.

[0041] like Figure 1 As shown, when the charging cable includes a neutral wire and a live wire, this embodiment uses two relays to control the on / off state of the charging cable respectively. The relays include relay K1 and relay K2. The positive and negative terminals of the coils of relay K1 and relay K2 are connected in parallel in the same direction. The contact pins of relay K1 and relay K2 control the on / off state of the neutral wire and the live wire respectively.

[0042] The charging circuit of this embodiment also includes an emergency stop unit, which is connected in series between the transmission unit and ground or between the relay unit and ground.

[0043] like Figure 1 As shown, in this embodiment, the emergency stop unit is connected in series between the relay unit and the ground. The emergency stop unit includes an emergency stop switch X1. The emergency stop switch X1 includes a control pin 1 and a ground pin 2. The control pin 1 is connected to the relay unit, and the ground pin 2 is grounded. The control pin 1 and the ground pin 2 are normally closed. When the emergency stop switch is pressed, the control pin 1 and the ground pin 2 are open.

[0044] To improve the overall safety of the charging circuit, such as Figure 1 As shown, the emergency stop unit incorporates a fuse R5, which is connected in series between the grounding pin of the emergency stop switch X1 and ground.

[0045] like Figure 1 As shown, the emergency stop unit also includes a PNP transistor Q3, resistors R6 and R7; the control pin is connected to the base of the PNP transistor Q3, the collector of the PNP transistor Q3 is connected to ground via resistor R6, the emitter of the PNP transistor Q3 is connected to one end of resistor R7 and the emergency stop signal output terminal CPU-JT, and the other end of resistor R7 is connected to the power supply voltage VCC of the charging control module. The power supply voltage VCC of the charging control module is less than the operating voltage +V of the relay coil.

[0046] In addition to manually pressing the emergency stop switch to open the control pin 1 and ground pin 2, this embodiment also incorporates emergency stop signal control feedback. During an emergency stop, the emergency stop signal is fed back to the charging control module via the emergency stop signal output terminal CPU-JT. The power supply of the charging control module is less than the relay coil's startup voltage. Therefore, when an emergency stop occurs, the charging control module's power supply voltage VCC is transmitted to the positive terminal of the relay coil via the still-operational PNP transistor Q3 and diode D1, preventing the relay from starting.

[0047] Example 2

[0048] This embodiment describes a charging pile, including a charging control module and the charging circuit described in Embodiment 1. The charging signal output terminal CPU-KZ of the charging control module is connected to one end of resistor R1.

[0049] like Figure 1 This is a schematic diagram of the circuit structure of a charging circuit included in a charging pile.

[0050] The following is a detailed introduction. Figure 1 Circuit operation:

[0051] The control pin 1 and ground pin 2 of the emergency stop switch X1 are normally closed. After the charging pile is powered on, the relay coil operating voltage +V and the power supply voltage VCC of the charging control module maintain a stable voltage. In this embodiment, the relay coil operating voltage +V is 12V and the power supply voltage VCC of the charging control module is 3.3V.

[0052] When the charging station is charging:

[0053] The charging control module of the charging pile sends a charging signal to the charging signal output terminal CPU_KZ. The charging signal output terminal CPU_KZ is at a high level and passes through resistor R1 to the base of NPN transistor Q1. The base voltage of NPN transistor Q1 is greater than the grounded emitter voltage, which makes NPN transistor Q1 conduct.

[0054] When NPN transistor Q1 is turned on, the relay coil operating voltage +V is divided by resistors R3 and R2 to generate the gate voltage of P-channel MOSFET Q2. Thus, the gate voltage of P-channel MOSFET Q2 is lower than the source voltage of P-channel MOSFET Q2, and P-channel MOSFET Q2 is turned on.

[0055] When the P-channel MOSFET Q2 is turned on, the drain voltage and source voltage of the P-channel MOSFET Q2 are approximately equal, which is close to the operating voltage +V of the relay coil. This voltage is applied to one end of the resistor R4 and the positive terminal of the electrolytic capacitor C1. Since the capacitor voltage cannot change abruptly, the voltage +V is applied to the positive terminals of the coils of the AC charging pile relays K1 and K2, causing the contact pins of the relay units K1 and K2 to close. Relay K1 controls the neutral wire N to conduct, and relay K2 controls the live wire L to conduct, and the charging pile starts charging.

[0056] As the relay coil operating voltage +V finishes charging the electrolytic capacitor C1, the relay coil operating voltage +V supplies current to the positive terminals of the coils of relays K1 and K2 through resistor R4, keeping the relay control coils engaged and the relay contacts closed. Due to the current limiting effect of resistor R4, the holding current supplied to the relay coils is lower than the starting current, allowing the relay coils to remain engaged at a lower current than the starting current. This reduces the heating of the relay coils, improves the relay temperature rise, and enhances the relay stability, thereby improving the charging stability of the charging pile.

[0057] When the charging station stops charging:

[0058] The charging control module of the charging pile sends a stop signal to the charging signal output terminal CPU_KZ. The charging signal output terminal CPU_KZ is at a low level and passes through resistor R1 to the base of NPN transistor Q1. The base voltage of NPN transistor Q1 is not greater than the grounded emitter voltage, so that NPN transistor Q1 is turned off.

[0059] When NPN transistor Q1 is off, there is no voltage difference between the gate and source of P-channel MOSFET Q2, and P-channel MOSFET Q2 is off.

[0060] When the P-channel MOSFET Q2 is turned off, the relay unit has no external power supply, disconnects due to power failure, disconnects the neutral and live wires, and stops charging.

[0061] If the emergency stop switch is not pressed:

[0062] The emergency stop switch is a key device for AC charging stations to immediately stop charging in case of emergencies. When an abnormal situation or danger occurs at the charging station, pressing the emergency stop switch can immediately stop charging.

[0063] The control pin 1 and grounding pin 2 of the emergency stop switch X1 are normally closed, which allows the negative terminals of the coils of relays K1 and K2 to be grounded through fuse R5, so that the charging pile can charge normally after the contacts of relays K1 and K2 are closed.

[0064] Fuse R5 is a resistor with a very small resistance value. It melts first when an overcurrent occurs, reliably cutting off the circuit and thus protecting the circuit. The fuse can be a special fuse or a self-resetting fuse.

[0065] During normal charging, the base voltage of PNP transistor Q3 is zero, and the emitter voltage of PNP transistor Q3 is greater than the base voltage, so PNP transistor Q3 is turned on. The collector of PNP transistor Q3 is grounded through the current-limiting resistor R6. According to the fact that the collector and emitter voltages of PNP transistor Q3 are approximately equal when it is turned on, the emitter voltage of PNP transistor Q3 is very small. Therefore, the emergency stop signal output terminal CPU-JT connected to the emitter of PNP transistor Q3 is at a low level. That is, when the emergency stop switch is normally closed with control pin 1 and ground pin 2 connected, the circuit can charge normally.

[0066] Press the emergency stop switch:

[0067] When a charging station malfunctions or becomes dangerous, manually press the emergency stop switch X1 to open the circuit between control pin 1 and ground pin 2.

[0068] The current flows from the emitter to the base and collector in PNP transistor Q3, but not from the base to the emitter. This is determined by the unidirectional conductivity of the PN junction and the operating principle of the transistor. Therefore, with the negative terminals of relays K1 and K2 floating and no current flowing, relays K1 and K2 immediately disconnect, breaking the connection between the neutral and live wires and stopping charging.

[0069] With the base of PNP transistor Q3 floating, PNP transistor Q3 is cut off. The power supply voltage VCC of the charging control module is transmitted to the emergency stop signal output terminal CPU-JT after being current-limited by resistor R7, so that the emergency stop signal output terminal CPU-JT outputs a high level and forwards the emergency stop signal to the charging control module. After receiving the emergency stop signal, the charging module converts the original output charging signal into a stop signal and outputs it to the charging signal output terminal CPU-KZ.

[0070] The embodiments of the present utility model have been described above with reference to the accompanying drawings. However, the present utility model is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present utility model without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present utility model.

Claims

1. A charging circuit, characterized in that, Includes a transmission unit and a relay unit. The transmission unit is used to receive the charging or stopping signal output by the charging control module and transmit the signal to the relay unit connected in series; The relay unit is used to control the on / off state of the charging cable by means of a relay based on the signal transmitted by the receiving and transmitting unit.

2. The charging circuit according to claim 1, characterized in that, The transmission unit includes resistors R1, R2, and R3, an NPN transistor Q1, and a P-channel MOSFET Q2. One end of resistor R1 is connected to the charging signal output terminal, and the other end of resistor R1 is connected to the base of NPN transistor Q1. The emitter of NPN transistor Q1 is grounded. The collector of NPN transistor Q1 is connected to one end of resistor R2, and the other end of resistor R2 is connected to the gate of P-channel MOSFET Q2. Resistor R3 is connected in parallel between the gate and source of P-channel MOSFET Q2. The source of P-channel MOSFET Q2 is connected to the relay coil operating voltage +V. The drain of P-channel MOSFET Q2 is connected to one end of the relay unit, and the other end of the relay unit is grounded. The charging signal output terminal is the port for the charging control module to output charging or stop signals. The relay unit controls the on / off state of the charging line through the relay.

3. The charging circuit according to claim 2, characterized in that, It also includes a fast start unit, which includes a resistor R4 and an electrolytic capacitor C1. The resistor R4 and the electrolytic capacitor are connected in parallel between the drain of the P-channel MOSFET Q2 and the relay unit. The positive terminal of the electrolytic capacitor C1 is connected to the drain of the MOSFET.

4. The charging circuit according to claim 3, characterized in that, The relay unit includes a diode D1 and a relay; The relay includes coil pins and contact pins. The coil pins include a positive coil terminal and a negative coil terminal. The contact pins control the on / off state of the charging cable. The positive terminal of the coil is connected to the negative terminal of the electrolytic capacitor C1, and the negative terminal of the coil is grounded. The positive and negative terminals of the diode D1 are connected in parallel with the positive and negative terminals of the coil in opposite directions.

5. The charging circuit according to claim 4, characterized in that, When the charging cable includes a neutral wire and a live wire, the relay includes relay K1 and relay K2, with the positive and negative terminals of the coils of relay K1 and relay K2 connected in parallel in the same direction; the contact pins of relay K1 and relay K2 control the on / off state of the neutral wire and the live wire, respectively.

6. The charging circuit according to claim 5, characterized in that, It also includes an emergency stop unit, which is connected in series between the transmission unit and ground or between the relay unit and ground.

7. The charging circuit according to claim 5, characterized in that, It also includes an emergency stop unit, which is connected in series between the relay unit and the ground, and the emergency stop unit includes an emergency stop switch X1; The emergency stop switch X1 includes a control pin and a ground pin. The control pin is connected to the relay unit, and the ground pin is grounded. The control pin and the ground pin are normally closed. When the emergency stop switch is pressed, the control pin and the ground pin are open.

8. The charging circuit according to claim 7, characterized in that, The emergency stop unit also includes a fuse R5, which is connected in series between the grounding pin of the emergency stop switch X1 and ground.

9. The charging circuit according to claim 7 or 8, characterized in that, The emergency stop unit also includes a PNP transistor Q3, a resistor R6, and a resistor R7; The control pin is connected to the base of PNP transistor Q3. The collector of PNP transistor Q3 is connected to resistor R6 and ground. The emitter of PNP transistor Q3 is connected to one end of resistor R7 and the emergency stop signal output terminal, respectively. The other end of resistor R7 is connected to the power supply voltage VCC of the charging control module. The power supply voltage VCC of the charging control module is less than the operating voltage +V of the relay coil.

10. A charging pile, characterized in that, It includes a charging control module and a charging circuit as described in any one of claims 1 to 9, wherein the charging signal output terminal of the charging control module is connected to one end of a resistor R1.

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