Protection circuit and electric tail gate

Abstract

The utility model discloses a protection circuit and an electric tail gate, the protection circuit comprises an anti-reverse connection protection module, an HBD driving module and an MCU module, the anti-reverse connection protection module comprises a power supply interface, an MOS tube driving circuit, a reverse connection leakage current protection circuit and a current driving circuit, the power supply interface is used for connecting an external power supply for power connection, and the current driving circuit is used for driving the reverse connection leakage current protection circuit. The power supply interface is respectively connected with the MOS tube driving circuit and the reverse connection discharge protection circuit, the power supply interface is further connected with the MCU module through the diode D3, the positive electrode of the diode D3 is connected with the power supply interface, the negative electrode of the diode D3 is connected with the MCU module, the MCU module and the HBD driving module are both connected with the current driving circuit, the reverse connection discharge protection circuit is further connected with the HBD driving module, and the HBD driving module is connected with the current driving circuit. The HBD driving module is used for being connected with a load, and the load at least comprises a supporting rod motor. According to the utility model, the reverse connection protection of the power supply is realized, the resistance of manually operating the tail door of the automobile in a non-power-on mode is reduced, and the user experience is improved.

Description

Technical Field

[0001] This utility model relates to the field of automobile tailgate control circuit technology, specifically a protection circuit and an electric tailgate. Background Technology

[0002] In new energy vehicles, the tailgate is typically opened and closed using a strut motor. When the vehicle is powered on, the strut motor is energized and functions normally, enabling the tailgate to open and close. When not powered on, the tailgate needs to be opened and closed manually. When the tailgate is manually operated, the strut motor acts as a generator, providing power to external systems.

[0003] To address the issue of tailgate slamming during manual operation, one existing solution involves short-circuiting both ends of the strut motor to increase its resistance, making it extremely difficult to manually pry open the tailgate and thus preventing it from slamming. While this solution provides protection, the tailgate becomes extremely difficult to operate manually when the vehicle is not powered on, causing inconvenience in some practical scenarios. For example, during vehicle manufacturing, the inability to easily and quickly open and close the tailgate disrupts production. Similarly, consumers may experience a poor experience if they need to open the tailgate in an emergency but are unable to do so. Utility Model Content

[0004] In view of the shortcomings of the prior art, the purpose of this utility model is to provide a protection circuit and an electric tailgate, which can solve the problems described in the background art.

[0005] The technical solution to achieve the purpose of this utility model is as follows: a protection circuit and an electric tailgate, including a reverse connection protection module, an HBD drive module, and an MCU module. The reverse connection protection module includes a power interface, a MOSFET drive circuit, a reverse connection leakage protection circuit, and a current drive circuit. The power interface is used to connect to an external power source and is connected to the MOSFET drive circuit and the reverse connection leakage protection circuit. The power interface is also connected to the MCU module through diode D3. The anode of diode D3 is connected to the power interface, and the cathode of diode D3 is connected to the MCU module. Both the MCU module and the HBD drive module are connected to the current drive circuit. The reverse connection leakage protection circuit is also connected to the HBD drive module. The HBD drive module is used to connect a load, which includes at least a strut motor.

[0006] When an external power source is connected to the power interface, the reverse connection leakage protection circuit is in the off state, allowing only the current from the external power source to flow into the HBD drive module. This continues until the MCU module sends a drive signal to the current drive circuit, causing the reverse connection leakage protection circuit to turn on and allow a larger current to flow.

[0007] An external power supply powers the MCU module through diode D3. After the MCU module is powered on, it sends a drive signal to the current drive circuit. After receiving the drive signal, the current drive circuit is in a closed state.

[0008] Furthermore, the MOS transistor driving circuit includes a diode D1, a transistor Q1, a resistor R2, and a resistor R3. The cathode of the diode D1 is connected to the power interface, and the anode of the diode D1 is connected to one end of the resistor R2 and the emitter of the transistor Q1. The other end of the resistor R2 and the base of the transistor Q1 are connected in series with the resistor R3 and then grounded. The collector of the transistor Q1 is connected to the reverse connection leakage protection circuit.

[0009] Furthermore, the reverse connection leakage protection circuit includes a MOSFET Q2, a diode D2, a resistor R1, and a resistor R4. The anode of diode D2, the first end of resistor R1, and the source of the MOSFET are connected to the power interface. The cathode of diode D2, the other end of resistor R1, the gate of MOSFET Q2, and one end of resistor R4 are connected together and then connected to the collector of transistor Q1. The other end of resistor R4 is connected to the current drive circuit, and the drain of MOSFET Q2 is connected to the HBD drive module.

[0010] Furthermore, the current drive circuit includes a PUMP circuit, transistors Q3 and Q4, resistors R5, R6, R7, and R8. The collector of transistor Q3 is connected to the other end of resistor R4, thereby connecting the current drive circuit to the reverse connection leakage protection circuit. The emitter of transistor Q3 and one end of resistor R5 are connected to the output terminal of the PUMP circuit. The input terminal of the PUMP circuit is connected to the HBD drive module. The base of transistor Q3 is connected to the other end of resistor R5, then connected in series with resistor R6 and then to the collector of transistor Q4. The emitter of transistor Q4 and one end of resistor R8 are grounded together. The base of transistor Q4 is connected to one end of resistor R7 and one end of resistor R8, respectively. The other end of resistor R8 is connected to the MCU module.

[0011] Furthermore, the MCU module includes an MCU, the power-on pin of the MCU is connected to the negative terminal of diode Q3, the signal output pin of the MCU is connected to the HBD driver module, and the signal output pin of the MCU forms an SPI interface and is connected to the HBD driver module.

[0012] Furthermore, the HBD drive module includes a bridge drive chip and MOSFETs Q6-Q9. The gates of each of MOSFETs Q6-Q9 are connected to the bridge drive chip. The drains of MOSFETs Q6 and Q8 are connected to the drain of MOSFET Q2 and then connected to the power-on pin of the bridge drive chip. The gates of MOSFETs Q6 and Q8, the drain of MOSFET Q7, and the drain of MOSFET Q8 are all connected to the strut motor. The sources of MOSFETs Q7 and Q9 are grounded together.

[0013] Furthermore, when the negative terminal of the external power supply is connected to the power interface and the positive terminal of the external power supply is grounded, the external power supply forms a loop through the MOSFET drive circuit to disable the MOSFET Q2 from conducting.

[0014] Furthermore, when the external power supply is not connected to the power interface, the current output by the strut motor flows into the bridge driver chip through the freewheeling diodes in MOSFETs Q6-Q9, causing the bridge driver chip to start. After starting, the bridge driver chip automatically controls MOSFETs Q6-Q9 to turn on and off to discharge current under the control signal sent by the MCU of the MCU module.

[0015] After the bridge driver chip starts up, the current output by the bridge driver chip drives the synchronous PUMP circuit to input current to transistor Q3. When the current flows through transistor Q3 and resistor R4, it flows into transistor Q2, causing MOSFET Q2 to turn on and become conductive. This allows the current of the strut motor to supply power to the equivalent load through MOSFET Q2. The equivalent load includes at least the power interface, the load flowing into the MCU through the power interface, and the load connected to the power interface.

[0016] Furthermore, the resistor R8 is used to reduce the voltage difference between the base and emitter of transistor Q4, thereby keeping transistor Q4 in the off state.

[0017] When transistor Q4 is in the off state, resistor R5 reduces the voltage difference between the base and emitter of transistor Q3, causing transistor Q3 to also turn off. This switches both transistors Q3 and Q4 from the on state to the off state. Resistor R1 reduces the voltage difference between the gate and source of MOSFET Q2, causing MOSFET Q2 to turn off. Consequently, the current generated by the strut motor cannot pass through MOSFET Q2, and therefore cannot discharge current to the downstream load connected to MOSFET Q2, thus reducing the equivalent load of the strut motor. This reduces the resistance to opening and closing the car tailgate in the off-power mode.

[0018] This utility model also provides an electric tailgate, including a control circuit, the control circuit including the aforementioned protection circuit.

[0019] The beneficial effects of this utility model are as follows: This utility model not only provides protection against reverse power connection, but also achieves the effect of protection circuit through a circuit based on transistors. It also reduces the resistance of manually operating the tailgate in non-power-on mode, thereby ensuring that the tailgate can still be easily opened and closed in non-power-on mode when the power supply (battery) is disconnected. This improves the success rate of opening and closing the tailgate in emergency situations or during the manufacturing process, and enhances the user experience. Attached Figure Description

[0020] Figure 1 A schematic diagram of the circuit principle of this utility model;

[0021] Figure 2 A schematic diagram of the circuit structure for the reverse connection protection module;

[0022] Figure 3 This is a schematic diagram of the circuit structure of the HBD driver module. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0024] like Figures 1-3 As shown, this embodiment provides a protection circuit, including a reverse connection protection module, an HBD drive module, and an MCU module. The reverse connection protection module includes a power interface (i.e., the POWER IN node in the figure), a MOSFET drive circuit, a reverse connection leakage protection circuit, and a current drive circuit. The power interface is used to connect to an external power source, such as a car battery (as the car's power source). The power interface is connected to the MOSFET drive circuit and the reverse connection leakage protection circuit, respectively. The power interface is also connected to the MCU module through diode D3. The positive terminal of diode D3 is connected to the power interface, and the negative terminal of diode D3 is connected to the MCU module to supply power to the MCU module. Both the MCU module and the HBD drive module are connected to the current drive circuit. The reverse connection leakage protection circuit is also connected to the HBD drive module. The HBD drive module is used to connect a load, which includes at least a strut motor (the component marked with M in the figure is the strut motor).

[0025] When the power interface is connected to an external power source, i.e., in power-on mode, the positive terminal of the external power source is connected to the power interface, and the external power source supplies power to the MCU module through the power interface and diode D3. The MCU module enters the working state when powered on. The MCU module sends a drive signal to the current drive circuit. After receiving the drive signal, the current drive circuit enters a closed state, allowing current to flow through the current drive circuit and then through the reverse connection leakage protection circuit to flow into the HBD drive module. This allows a larger current to flow through the reverse connection leakage protection circuit, enabling a larger input current to drive a larger load through the HBD drive module.

[0026] The external power supply also supplies power to the reverse connection leakage protection circuit through the power interface, so that the current flows into the HBD drive module after passing through the reverse connection leakage protection circuit. The current input by the external power supply to the reverse connection leakage protection circuit through the power interface is recorded as the first current.

[0027] After the HBD drive module is powered on, it supplies power to the current drive circuit, which in turn supplies power to the reverse connection leakage protection circuit. While the current drive circuit is supplying power to the reverse connection leakage protection circuit, the reverse connection leakage protection circuit is in a closed (disconnected) state until the current drive circuit receives a drive signal, at which point the reverse connection leakage protection circuit becomes open again. Once the reverse connection leakage protection circuit becomes open again, the input current from the external power supply and the current drive circuit to the reverse connection leakage protection circuit is denoted as the second current. The second current is greater than the first current, meaning the value of the second current is greater than the value of the first current. This allows for a larger output current, enabling the HBD drive module to drive a larger load.

[0028] The HBD driver module and the MCU module work together to allow the reverse connection leakage protection circuit to allow a larger current to pass through, so that a larger current flows into the HBD driver module, thereby enabling the HBD driver module to meet the driving requirements of high-power loads.

[0029] For example, the MOS transistor driving circuit includes a diode D1, a transistor Q1, a resistor R2, and a resistor R3. The cathode of the diode D1 is connected to the power interface, and the anode of the diode D1 is connected to one end of the resistor R2 and the emitter of the transistor Q1. The other end of the resistor R2 and the base of the transistor Q1 are connected in series with the resistor R3 and then grounded. The collector of the transistor Q1 is connected to the reverse connection leakage protection circuit.

[0030] For example, the reverse connection leakage protection circuit includes a MOSFET Q2, a diode D2, a resistor R1, and a resistor R4. The anode of diode D2, the first terminal of resistor R1, and the first terminal (source) of the MOSFET are connected to the power interface. The cathode of diode D2, the other terminal of resistor R1, the second terminal (gate) of MOSFET Q2, and one terminal of resistor R4 are connected together and then connected to the collector of transistor Q1, thereby connecting the reverse connection leakage protection circuit to the MOSFET driving circuit. The other terminal of resistor R4 is connected to the current driving circuit, and the third terminal (drain) of MOSFET Q2 is connected to the HBD driving module, thereby connecting the reverse connection leakage protection circuit to the HBD driving module.

[0031] For example, the current drive circuit includes a PUMP circuit (i.e., a charge pump circuit), transistors Q3 and Q4, resistors R5, R6, R7, and R8. The collector of transistor Q3 is connected to the other end of resistor R4, thereby connecting the current drive circuit to the reverse connection leakage protection circuit. The emitter of transistor Q3 and one end of resistor R5 are connected to the output of the PUMP circuit, and the input of the PUMP circuit is connected to the HBD driver module. The base of transistor Q3 is connected to the other end of resistor R5, then connected in series with resistor R6 and then to the collector of transistor Q4. The emitter of transistor Q4 and one end of resistor R8 are grounded together. The base of transistor Q4 is connected to one end of resistor R7 and one end of resistor R8, and the other end of resistor R8 is connected to the MCU module.

[0032] For example, the MCU module includes an MCU, the power-on pin of the MCU is connected to the negative terminal of diode Q3, the signal output pin of the MCU is connected to the HBD driver module, and the signal output pin of the MCU can be connected to the HBD driver module through the SPI interface, that is, the signal output pin on the MCU constitutes the SPI interface.

[0033] For example, the HBD drive module includes a bridge drive chip (HBD in the figure), MOSFETs Q6-Q9, the gates of each of MOSFETs Q6-Q9 are connected to the bridge drive chip, the drains of MOSFETs Q6 and Q8 are connected to the drain of MOSFET Q2 and then connected to the power-on pin of the bridge drive chip, the gates of MOSFETs Q6 and Q8, the drains of MOSFETs Q7 and Q8 are connected to the strut motor, and the sources of MOSFETs Q7 and Q9 are grounded together.

[0034] Operating Principle: When the power supply is positive and in power-on mode (i.e., the positive terminal of the external power supply is connected to the power interface and the negative terminal is grounded), MOSFET Q2 is in a closed (not conducting) state. Therefore, only a small current is allowed to flow through MOSFET Q2, allowing current from the external power supply to flow into the power pin of the bridge driver chip. This small current (i.e., the first current) is just enough to allow the bridge driver chip to operate. The bridge driver chip enters the operating state and supplies power to the PUMP circuit, thus turning on the PUMP circuit. At this time, MOSFET Q2's VGS level is maintained at 0V through resistor R1, keeping MOSFET Q2 in a closed (not conducting) state. This allows only a small current from the external power supply to flow into the HBD driver module through MOSFET Q2.

[0035] Simultaneously, in power-on mode, the external power supply synchronously supplies power to the MCU module through diode D3. After the MCU module is powered on, it sends a drive signal to the current drive circuit, which outputs a current to transistor Q4 through resistor R7, thereby turning on transistors Q3 and Q4. This allows the current output from the PUMP circuit to flow through resistor R4 and into MOSFET Q2. Diode D2 clamps the VGS level of MOSFET Q2 to the voltage required to turn on MOSFET Q2, thus turning on MOSFET Q2. With MOSFET Q2 on, a large current (a larger value than the current allowed when MOSFET Q2 is off) can flow through MOSFET Q2, allowing the large current to power the bridge driver chip of the HBD driver module. At this time, MOSFETs Q6-Q9 can be controlled by the MCU to turn on the bridge driver chip, putting the bridge driver chip into working state, thus meeting the driving needs of high-power loads.

[0036] When the power supply is reversed, meaning the negative terminal of the external power supply is connected to the power interface and the positive terminal is grounded, the current from the external power supply flows out from the positive terminal, through resistor R3, and then sequentially through transistor Q1 and diode D1, returning to the negative terminal of the external power supply. This means the external power supply forms a loop through the MOSFET driver circuit. This prevents MOSFET Q2 from conducting, allowing only small currents to pass through it and preventing large currents from flowing through it. This ensures that reverse connection will not damage the load, thus achieving reverse connection protection.

[0037] When the power supply is in non-power-on mode, meaning the external power supply is not connected to the power interface (e.g., the external power supply is turned off or there is no physical connection between the external power supply and the power interface), manual operation of the car tailgate (i.e., opening and closing the tailgate) is required. The strut motor connected to the tailgate acts as a generator. The current output by the strut motor flows through the freewheeling diodes (body diodes) within MOSFETs Q6-Q9 and then into the bridge driver chip, causing the bridge driver chip to start. After starting, the bridge driver chip automatically controls the opening and closing of MOSFETs Q6-Q9 to discharge current under the control signal sent by the MCU of the MCU module. Specifically, after the bridge driver chip starts, upon receiving the control signal, it detects the back electromotive force (EMF) acting on MOSFETs Q6-Q9. By detecting the back EMF acting on MOSFETs Q6-Q9, it automatically controls the opening and closing of the MOSFETs to discharge current. After the bridge driver chip starts, the PUMP circuit is simultaneously turned on, and the bridge driver chip also inputs current to transistor Q3. When current flows through transistor Q3 and resistor R4, it flows into transistor Q2, causing MOSFET Q2 to turn on and become conductive. This allows the current from the strut motor to power the entire system through MOSFET Q2. Specifically, the current output from the strut motor flows through MOSFET Q2 to the power interface (at which point the external power supply is disconnected from the power interface), then through the power interface to the MCU, and finally to other loads connected to the power interface, thus powering the entire system. Because the strut motor needs to power other loads, the resistance of the car tailgate increases.

[0038] Because the resistance of the car tailgate increases, resistor R8 is included. The function of resistor R8 is to reduce the voltage difference between the base and emitter of transistor Q4, keeping transistor Q4 in the off state. When transistor Q4 is off, the presence of resistor R1 reduces the voltage difference between the gate and source of MOSFET Q2, causing MOSFET Q2 to turn off. The current generated by the strut motor cannot pass through MOSFET Q2, thus preventing current discharge to the downstream load connected to MOSFET Q2.

[0039] Similarly, due to the presence of resistor R5, the voltage difference between the base and emitter of transistor Q3 is reduced, causing transistor Q3 to turn off. This causes both transistors Q3 and Q4 to switch from the on to the off state, thereby reducing the equivalent load on the strut motor and thus reducing the resistance to opening and closing the tailgate. This allows the tailgate to be opened and closed manually and easily even when not powered on.

[0040] The output current of the strut motor is equal to that of the bridge drive chip. After the bridge drive chip is started, it opens the PUMP circuit. In a very short time, the current input to the PUMP circuit passes through transistor Q3 and resistor R4, and then flows into MOSFET Q2, causing MOSFET Q2 to turn on. This allows current to flow into MOSFETs Q6-Q9 and the strut motor, thereby increasing the resistance of the car tailgate.

[0041] Because of the presence of resistor R8 and the fact that the circuit is in a non-powered mode, the voltage between the base and emitter of transistor Q4 is 0, and the base current is 0, so transistor Q4 is in the off state. When transistor Q4 is in the off state, the voltage between the base and emitter of transistor Q3 is also relatively low, causing transistor Q3 to also become off, thus switching transistor Q3 from the on state to the off state. This reduces the equivalent load on the strut motor, decreases resistance, and allows the car tailgate to be opened and closed even in a non-powered mode.

[0042] This utility model also provides an electric tailgate, including a control circuit, the control circuit including the aforementioned protection circuit.

[0043] This invention provides protection against reverse power connection and, through a transistor-based circuit, achieves the same protection effect. It also reduces the resistance of manually operating the tailgate in non-power-on mode, ensuring that the tailgate can still be easily opened and closed even when the power (battery) is disconnected. This improves the success rate of opening and closing the tailgate in emergency situations or during manufacturing processes, and enhances the user experience.

[0044] The embodiments disclosed in this specification are merely illustrative of one aspect of the features of this utility model. The protection scope of this utility model is not limited to this embodiment, and any other functionally equivalent embodiments fall within the protection scope of this utility model. Those skilled in the art can make various other corresponding changes and modifications based on the technical solutions and concepts described above, and all such changes and modifications should fall within the protection scope of the claims of this utility model.

Claims

1. A protection circuit, characterized by, The system includes a reverse connection protection module, an HBD driver module, and an MCU module. The reverse connection protection module comprises a power interface, a MOSFET driver circuit, a reverse connection leakage current protection circuit, and a current drive circuit. The power interface is used to connect to an external power source and is connected to both the MOSFET driver circuit and the reverse connection leakage current protection circuit. The power interface is also connected to the MCU module via diode D3, with the anode of diode D3 connected to the power interface and the cathode connected to the MCU module. Both the MCU module and the HBD driver module are connected to the current drive circuit. The reverse connection leakage current protection circuit is also connected to the HBD driver module. The HBD driver module is used to connect to the load, which includes at least a strut motor. When an external power source is connected to the power interface, the reverse connection leakage protection circuit is in the off state, allowing only the current from the external power source to flow into the HBD drive module. This continues until the MCU module sends a drive signal to the current drive circuit, causing the reverse connection leakage protection circuit to turn on and allow a larger current to flow. An external power supply powers the MCU module through diode D3. After the MCU module is powered on, it sends a drive signal to the current drive circuit. After receiving the drive signal, the current drive circuit is in a closed state.

2. The protection circuit of claim 1, wherein, The MOS transistor driving circuit includes a diode D1, a transistor Q1, a resistor R2, and a resistor R3. The cathode of the diode D1 is connected to the power interface, and the anode of the diode D1 is connected to one end of the resistor R2 and the emitter of the transistor Q1. The other end of the resistor R2 and the base of the transistor Q1 are connected in series with the resistor R3 and then grounded. The collector of the transistor Q1 is connected to the reverse connection leakage protection circuit.

3. The protection circuit of claim 2, wherein, The reverse connection leakage protection circuit includes MOSFET Q2, diode D2, resistor R1, and resistor R4. The anode of diode D2, the first end of resistor R1, and the source of MOSFET are connected to the power interface. The cathode of diode D2, the other end of resistor R1, the gate of MOSFET Q2, and one end of resistor R4 are connected together and then connected to the collector of transistor Q1. The other end of resistor R4 is connected to the current drive circuit. The drain of MOSFET Q2 is connected to the HBD drive module.

4. The protection circuit of claim 3, wherein, The current drive circuit includes a PUMP circuit, transistors Q3 and Q4, resistors R5, R6, R7, and R8. The collector of transistor Q3 is connected to the other end of resistor R4, thus connecting the current drive circuit to the reverse connection leakage protection circuit. The emitter of transistor Q3 and one end of resistor R5 are connected to the output of the PUMP circuit. The input of the PUMP circuit is connected to the HBD drive module. The base of transistor Q3 is connected to the other end of resistor R5, then connected in series with resistor R6 and then to the collector of transistor Q4. The emitter of transistor Q4 and one end of resistor R8 are grounded together. The base of transistor Q4 is connected to one end of resistor R7 and one end of resistor R8. The other end of resistor R8 is connected to the MCU module.

5. The protection circuit of claim 4, wherein, The MCU module includes an MCU, whose power-on pins are connected to the negative terminal of diode Q3, and whose signal output pins are connected to the HBD driver module. The MCU's signal output pins form an SPI interface and are connected to the HBD driver module.

6. The protection circuit of claim 5, wherein, The HBD drive module includes a bridge driver chip and MOSFETs Q6-Q9. The gates of each of MOSFETs Q6-Q9 are connected to the bridge driver chip. The drains of MOSFETs Q6 and Q8 are connected to the drain of MOSFET Q2 and then connected to the power-on pin of the bridge driver chip. The gates of MOSFETs Q6 and Q8, the drain of MOSFET Q7 and the drain of MOSFET Q8 are connected to the strut motor. The sources of MOSFETs Q7 and Q9 are grounded together.

7. The protection circuit of claim 6, wherein, When the negative terminal of the external power supply is connected to the power interface and the positive terminal of the external power supply is grounded, the external power supply forms a loop through the MOSFET drive circuit to disable the MOSFET Q2 from conducting.

8. The protection circuit of claim 7, wherein, When the external power supply is not connected to the power interface, the current output by the strut motor flows into the bridge driver chip through the freewheeling diodes in MOSFETs Q6-Q9, causing the bridge driver chip to start. After starting, the bridge driver chip automatically controls MOSFETs Q6-Q9 to turn on and off to discharge current under the control signal sent by the MCU of the MCU module. After the bridge driver chip starts up, the current output by the bridge driver chip drives the synchronous PUMP circuit to input current to transistor Q3. When the current flows through transistor Q3 and resistor R4, it flows into transistor Q2, causing MOSFET Q2 to turn on and become conductive. This allows the current of the strut motor to supply power to the equivalent load through MOSFET Q2. The equivalent load includes at least the power interface, the load flowing into the MCU through the power interface, and the load connected to the power interface.

9. The protection circuit according to claim 8, characterized in that, The resistor R8 is used to reduce the voltage difference between the base and emitter of transistor Q4, so that transistor Q4 is in the off state. When transistor Q4 is in the off state, resistor R5 reduces the voltage difference between the base and emitter of transistor Q3, causing transistor Q3 to also turn off. This switches both transistors Q3 and Q4 from the on state to the off state. Resistor R1 reduces the voltage difference between the gate and source of MOSFET Q2, causing MOSFET Q2 to turn off. Consequently, the current generated by the strut motor cannot pass through MOSFET Q2, and therefore cannot discharge current to the downstream load connected to MOSFET Q2, thus reducing the equivalent load of the strut motor. This reduces the resistance to opening and closing the car tailgate in the off-power mode.

10. An electric tailgate, characterized by It includes a control circuit, which includes a protection circuit as described in any one of claims 1-9.

Images