Cathode relay pull-in state detection circuit and vehicle

Abstract

The utility model provides a cathode relay pull-in state detection circuit and a vehicle, the cathode relay pull-in state detection circuit is used for detecting the pull-in state of a cathode relay of a battery pack, the cathode relay pull-in state detection circuit comprises an on-off unit, the output end of the on-off unit is connected between the cathode relay and a load; the input end of the detection unit is connected to the output end of the on-off unit, the output end of the detection unit is grounded, and the detection unit is used for outputting a detection signal; the input end of the acquisition unit is connected with the detection unit, the output end of the acquisition unit is connected with a load, and the acquisition unit is used for acquiring detection signals to judge the pull-in state of the cathode relay; and when the acquisition unit does not acquire the detection signal, the cathode relay is judged to be disconnected, and when the acquisition unit acquires the detection signal, the cathode relay is judged to be closed. The circuit for detecting the pull-in state of the cathode relay can detect the pull-in state of the cathode relay, the use safety of a battery pack is improved, and the use quality of a whole vehicle is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of battery packs, and particularly relates to a detection circuit for the suction state of a negative relay. The utility model also relates to a vehicle provided with the detection circuit for the suction state of the negative relay. Background Art

[0002] In electric vehicles driven by lithium batteries, high-voltage relays play a crucial role. They are responsible for controlling the power transmission between the battery pack and the electric motor, thus ensuring that the vehicle can start, accelerate and run normally. However, in the complex electrical system of electric vehicles, safety is always the primary consideration. Especially when dealing with high-voltage electricity, any electrical fault or operation error may lead to serious consequences.

[0003] To ensure the normal operation of high-voltage relays, it is necessary to monitor their states in real time. Among them, the most crucial thing is to know whether the relay has truly performed the expected suction and disconnection actions. Suction means that the contacts inside the relay have closed and electricity can flow smoothly; while disconnection means that the contacts have separated and the electricity is cut off.

[0004] However, relying solely on the electrical signals of the relay to judge its state is not always reliable. In some cases, due to external factors (such as overload, short circuit, etc.) or the aging and damage of the relay itself, the relay may remain in the suction state when it should be disconnected, or faults such as sintering and adhesion may occur. In this case, even if the electrical signal shows that the relay has been disconnected, in fact, electricity may still flow through the relay, thus causing potential safety hazards.

[0005] Therefore, in electric vehicles, in addition to monitoring the electrical signals of the relay, it is also necessary to detect whether the relay, including the positive and negative poles, has truly been suctioned. And because the negative relay is in the high-voltage circuit, it is difficult to directly measure its current or voltage information to judge its suction state. Summary of the Utility Model

[0006] In view of this, the utility model aims to propose a detection of the suction state of a negative relay, so as to be able to detect the suction state of the negative relay, improve the use safety of the battery pack, and improve the use quality of the whole vehicle.

[0007] To achieve the above object, the technical solution of the utility model is realized as follows:

[0008] A detection circuit for the suction state of a negative relay is used for detecting the suction state of the negative relay of a battery pack. The detection circuit includes:

[0009] An opening and closing unit, the output end of the opening and closing unit is connected between the negative relay and the load;

[0010] A detection unit, the input end of the detection unit is commonly connected to the output end of the opening and closing unit, the output end of the detection unit is grounded, and is used for outputting a detection signal;

[0011] An acquisition unit, the input end of the acquisition unit is connected to the detection unit, the output end of the acquisition unit is connected to the input end of the opening and closing unit, and is used for acquiring the detection signal to judge the suction state of the negative relay;

[0012] When the acquisition unit does not acquire the detection signal, it is judged that the negative relay is disconnected, and when the acquisition unit acquires the detection signal, it is judged that the negative relay is attracted.

[0013] Further, the opening and closing unit includes a first resistor, a first optocoupler, a second resistor, a first triode and a first diode;

[0014] The input end of the first resistor is connected to the first power supply unit, the output end of the first resistor is connected to the input end of the light-emitting device of the first optocoupler, the output end of the light-emitting device of the first optocoupler is connected to the collector of the first triode, the base of the first triode is connected to the output end of the acquisition unit, and the emitter of the first triode is grounded;

[0015] The input end of the photosensitive element of the first optocoupler is connected to the second power supply unit, the output end of the photosensitive element of the first optocoupler is connected to the first end of the second resistor, the second end of the second resistor is connected to the positive pole of the first diode, and the negative pole of the first diode is connected to the output end of the opening and closing unit.

[0016] Further, the first power supply unit is located on the low-voltage side, and the second power supply unit is located on the high-voltage side.

[0017] Further, the detection unit includes a second optocoupler and a third resistor;

[0018] The input end of the light-emitting device of the second optocoupler is commonly connected to the output end of the opening and closing unit, and the output end of the light-emitting device of the second optocoupler is grounded;

[0019] The first end of the third resistor is connected to the third power supply unit, the second end of the third resistor is connected to the input end of the photosensitive element of the second optocoupler, and the output end of the second optocoupler is grounded.

[0020] Further, the third power supply unit is located on the low-voltage side.

[0021] Further, it further includes a protection unit, the input end of the protection unit is commonly connected to the output end of the opening and closing unit, the output end of the protection unit is commonly connected to the output end of the light-emitting device of the second optocoupler, and is used for overvoltage, overcurrent, reverse voltage and surge impact protection of the light-emitting device of the second optocoupler.

[0022] Further, the protection unit includes a first capacitor, a second capacitor, a fourth resistor, a fifth resistor, a sixth resistor, a second diode, a seventh resistor, and a first voltage regulator diode;

[0023] The first end of the first capacitor is commonly connected to the output end of the opening and closing unit, the second end of the first capacitor is connected to the first end of the second capacitor, the second end of the second capacitor is commonly connected to the output end of the light-emitting device of the second optocoupler, and is used for surge impact protection of the light-emitting device of the second optocoupler;

[0024] The fourth resistor, the fifth resistor, and the sixth resistor are connected in series in sequence, and are connected in series between the output end of the opening and closing unit and the input end of the light-emitting device of the second optocoupler, and are used for overcurrent protection of the light-emitting device of the second optocoupler;

[0025] The second diode is connected in series between the fifth resistor and the sixth resistor, the positive electrode of the second diode is connected to the second end of the fifth resistor, the negative electrode of the second diode is connected to the first end of the seventh resistor, and is used for reverse voltage protection of the light-emitting device of the second optocoupler;

[0026] The first end of the seventh resistor is commonly connected to the positive electrode of the second diode, the second end of the seventh resistor is connected to the negative electrode of the first voltage regulator diode, the positive electrode of the first voltage regulator diode is connected to the output end of the light-emitting device of the second optocoupler, and is used for overvoltage protection of the light-emitting device of the second optocoupler, and the seventh resistor is used for overcurrent protection of the first voltage regulator diode.

[0027] Further, the acquisition unit includes an eighth resistor, a ninth resistor, and an MCU;

[0028] The first end of the eighth resistor is commonly connected to the input end of the photosensitive element of the second optocoupler, the second end of the eighth resistor is connected to the GPIO-0 port of the MCU;

[0029] The first end of the ninth resistor is connected to the GPIO-1 port of the MCU, and the second end of the ninth resistor is connected to the input end of the opening and closing unit.

[0030] Compared with the prior art, the present utility model has the following advantages:

[0031] The negative relay suction state detection circuit described in the present utility model enables the opening and closing of the detection circuit to be controllable through the setting of the opening and closing unit. When the opening and closing unit is turned on, the detection unit can output a detection signal, and the acquisition unit can judge the suction state of the negative relay according to the state of the detection signal, so as to accurately judge when it is necessary to judge the suction state of the relay, thereby being able to detect the adhesion or untimely disconnection of the negative relay, improving the safety of battery pack use, and facilitating design and implementation.

[0032] Through the setting of the first triode, the acquisition unit can control the opening and closing of the first optocoupler by regulating the on-off of the first triode, so as to better control the opening and closing of the opening and closing unit, facilitate the opening or closing of the detection circuit, and facilitate design and implementation.

[0033] By controlling the output of the detection signal through the opening and closing of the second optocoupler, the detection signal can be regulated according to the suction state of the negative relay, which is conducive to design and implementation.

[0034] The setting of the protection unit enables the detection unit to be better protected, preventing overvoltage, overcurrent, reverse breakdown and surge impact of the detection unit, facilitating the normal use of the protection detection unit, and contributing to design and implementation.

[0035] By the MCU collecting the signal of the detection unit and connecting to the base of the first triode of the opening and closing unit, it is convenient to regulate the on-off of the opening and closing unit, and the suction state of the negative relay can be better judged according to the level situation collected by the MCU.

[0036] Meanwhile, the present utility model also proposes a vehicle, including the negative relay suction state detection circuit described above.

[0037] The technical effects of the vehicle described in the present utility model compared with the prior art are the same as those of the negative relay suction state detection circuit described above, and will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The drawings constituting a part of the present utility model are used to provide a further understanding of the present utility model. The schematic embodiments and descriptions thereof of the present utility model are used to explain the present utility model and do not constitute an improper limitation to the present utility model. In the drawings:

[0039] Figure 1 It is a schematic diagram of the composition of the negative relay suction state detection circuit described in the embodiment of the present utility model;

[0040] Figure 2 It is a circuit diagram of the negative relay suction state detection circuit described in the embodiment of the present utility model;

[0041] Explanation of the reference numerals in the drawings:

[0042] 10. Opening and closing unit; 20. Detection unit; 30. Acquisition unit; 40. Protection unit;

[0043] R1. First resistor; R2. Second resistor; R3. Third resistor; R4. Fourth resistor; R5. Fifth resistor; R6. Sixth resistor; R7. Seventh resistor; R8. Eighth resistor; R9. Ninth resistor; C1. First capacitor; C2. Second capacitor; U1. First optocoupler; U2. Second optocoupler; D1. First diode; D2. Second diode; D3. First zener diode; Q1. First triode. Specific embodiments

[0044] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments may be combined with each other.

[0045] In the description of the present invention, it should be noted that if terms indicating orientation or positional relationship such as "upper", "lower", "inner", "outer", etc. appear, they are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation to the present invention. In addition, if terms such as "first", "second", etc. appear, they are also only for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0046] In addition, in the description of the present invention, unless otherwise clearly defined, the terms "installation", "connection", "connection", "connector" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in combination with specific situations.

[0047] The present invention will be described in detail below with reference to the drawings and in conjunction with embodiments.

[0048] Embodiment 1

[0049] The embodiment relates to a detection circuit for the suction state of a negative relay, which can detect the suction state of the negative relay, improve the use safety of the battery pack, and improve the use quality of the whole vehicle.

[0050] In terms of the overall structure, as Figure 1As shown in the figure, the negative relay suction state detection circuit of this embodiment is used for detecting the suction state of the negative relay of the battery pack. The detection circuit includes: an opening and closing unit 10, and the output end of the opening and closing unit 10 is connected between the negative relay and the load. A detection unit 20, the input end of the detection unit 20 is commonly connected to the output end of the opening and closing unit 10, the output end of the detection unit 20 is grounded, and it is used for outputting a detection signal. A collection unit 30, the output end of the collection unit is connected to the input end of the opening and closing unit, the input end of the collection unit 30 is connected to the detection unit 20, and it is used for collecting the detection signal to judge the suction state of the negative relay. When the collection unit 30 does not collect the detection signal, it is judged that the negative relay is disconnected. When the collection unit 30 collects the detection signal, it is judged that the negative relay is suctioned.

[0051] With the above settings, in the negative relay suction state detection circuit of this embodiment, the opening and closing of the detection circuit is controllable through the setting of the opening and closing unit 10. When the opening and closing unit 10 is opened, the detection unit 20 can output a detection signal, and the collection unit 30 can judge the suction state of the negative relay according to the state of the detection signal, so as to accurately judge when it is necessary to judge the suction state of the relay, thereby being able to detect the situation where the negative relay is stuck or not disconnected in time, and improving the use safety of the battery pack, which is beneficial to the design and implementation.

[0052] It should be noted that the negative relay suction state detection circuit in this embodiment is arranged on the high-voltage circuit. Among them, the opening and closing unit 10 is arranged on the high-voltage side of the high-voltage circuit, and the detection unit 20 and the sampling unit are arranged on the low-voltage side of the high-voltage circuit.

[0053] In order to better ensure the use effect of the opening and closing unit 10, as Figure 2 shown, the opening and closing unit 10 of the negative relay suction state detection circuit in this embodiment includes a first resistor R1, a first optocoupler U1, a second resistor R2, a first triode Q1 and a first diode D1.

[0054] Among them, the input end of the first resistor R1 is connected to the first power supply unit, the output end of the first resistor R1 is connected to the input end of the light-emitting device of the first optocoupler U1, the output end of the light-emitting device of the first optocoupler U1 is connected to the collector of the first triode Q1, the base of the first triode Q1 is connected to the output end of the collection unit 30, and the emitter of the first triode Q1 is grounded.

[0055] The input end of the photosensitive element of the first optocoupler U1 is connected to the second power supply unit. The output end of the photosensitive element of the first optocoupler U1 is connected to the first end of the second resistor R2. The second end of the second resistor R2 is connected to the positive electrode of the first diode D1. The negative electrode of the first diode D1 is connected to the output end of the opening and closing unit 10. Through the setting of the first triode Q1, the acquisition unit 30 can control the opening and closing of the first optocoupler U1 by regulating the on-off of the first triode Q1, so as to better control the opening and closing of the opening and closing unit 10, facilitate the opening or closing of the detection circuit, and is conducive to the design and implementation.

[0056] For better output of the detection signal, as Figure 2 shown, the detection unit 20 of the negative relay suction state detection circuit in this embodiment includes a second optocoupler U2 and a third resistor R3.

[0057] Among them, the input ends of the light emitters of the second optocoupler U2 are commonly connected to the output end of the opening and closing unit 10. The output ends of the light emitters of the second optocoupler U2 are grounded. The first end of the third resistor R3 is connected to the third power supply unit. The second end of the third resistor R3 is connected to the input end of the photosensitive element of the second optocoupler U2. The output end of the second optocoupler U2 is grounded. By opening and closing the second optocoupler U2, the output of the detection signal can be controlled, so that the detection signal can be regulated according to the suction state of the negative relay, which is conducive to the design and implementation.

[0058] For better protection of the detection unit 20, as Figure 2 shown, the negative relay suction state detection circuit in this embodiment further includes a protection unit 40. The input end of the protection unit 40 is commonly connected to the output end of the opening and closing unit 10. The output end of the protection unit 40 is commonly connected to the output end of the light emitter of the second optocoupler U2 and is used for overvoltage, overcurrent, reverse voltage and surge impact protection of the light emitter of the second optocoupler U2. The setting of the protection unit 40 enables the detection unit 20 to be better protected, preventing overvoltage, overcurrent, reverse breakdown and surge impact of the detection unit 20, which is conducive to protecting the normal use of the detection unit 20 and is helpful for the design and implementation.

[0059] Specifically, the protection unit 40 in this embodiment includes a first capacitor C1, a second capacitor C2, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a second diode D2, a seventh resistor R7 and a first zener diode D3.

[0060] Among them, the first end of the first capacitor C1 is commonly connected to the output end of the opening and closing unit 10, the second end of the first capacitor C1 is connected to the first end of the second capacitor C2, the second end of the second capacitor C2 is commonly connected to the output end of the light-emitting device of the second optocoupler U2, and is used for surge impact protection of the light-emitting device of the second optocoupler U2. The fourth resistor R4, the fifth resistor R5, and the sixth resistor R6 are connected in series in sequence, and are connected in series between the output end of the opening and closing unit 10 and the input end of the light-emitting device of the second optocoupler U2, and are used for overcurrent protection of the light-emitting device of the second optocoupler U2.

[0061] The second diode D2 is connected in series between the fifth resistor R5 and the sixth resistor R6. The positive electrode of the second diode D2 is connected to the second end of the fifth resistor R5, and the negative electrode of the second diode D2 is connected to the first end of the seventh resistor R7, and is used for reverse voltage protection of the light-emitting device of the second optocoupler U2.

[0062] The first end of the seventh resistor R7 is commonly connected to the positive electrode of the second diode D2, the second end of the seventh resistor R7 is connected to the negative electrode of the first zener diode D3, the positive electrode of the first zener diode D3 is connected to the output end of the light-emitting device of the second optocoupler U2, and is used for overvoltage protection of the light-emitting device of the second optocoupler U2. The seventh resistor R7 is used for overcurrent protection of the first zener diode D3.

[0063] In order to better collect detection signals and control the opening and closing of the opening and closing unit 10, as Figure 2 shown, the acquisition unit 30 of the negative relay suction state detection circuit in this embodiment includes an eighth resistor R8, a ninth resistor R9, and an MCU.

[0064] Among them, the first end of the eighth resistor R8 is commonly connected to the input end of the photosensitive element of the second optocoupler U2, the second end of the eighth resistor R8 is connected to the GPIO-0 port of the MCU, the first end of the ninth resistor R9 is connected to the GPIO-1 port of the MCU, the second end of the ninth resistor R9 is connected to the base of the first triode Q1, the power input pin of the MCU is connected to the fourth power supply unit, and the MCU is grounded. The MCU collects the signals of the detection unit 20, and connects the base of the first triode Q1 of the opening and closing unit 10, which is convenient for controlling the on-off of the opening and closing unit 10, and can better judge the suction state of the negative relay according to the level situation collected by the MCU.

[0065] Specifically, in this embodiment, the first power supply unit is a 5v power supply, the second power supply unit is a 12v power supply, the third power supply unit is a 5v power supply, and the fourth power supply unit is a 5v power supply.

[0066] More specifically, when the base of the first triode Q1 receives the electrical signal output from the GPIO-1 port of the acquisition unit 30 and the first triode Q1 is turned on, the first power supply unit supplies power to the light emitter of the first optocoupler U1, causing the first optocoupler U1 to conduct. The second power supply unit supplies power to the detection unit 20. If the negative relay is closed, the detection unit 20 does not generate a detection signal. If the negative relay is open, the detection unit 20 generates a detection signal. The acquisition unit 30 can determine the closed state of the negative relay based on the detection signal.

[0067] When the negative relay is open, the second power supply unit supplies power to the second optocoupler U2 through the output terminal of the opening and closing unit 10, causing the second optocoupler U2 to conduct. As a result, the detection signal output by the third power supply unit of the detection unit 20 is grounded, so that the acquisition unit 30 does not collect the detection signal, and it is determined that the negative relay is open. When the negative relay is closed, the second optocoupler U2 is open, enabling the acquisition unit 30 to collect the detection signal and determine that the negative relay is in the closed state.

[0068] It can be understood that the detection circuit in this embodiment can be used to determine the actual closed state of the negative relay. According to the actual negative relay closing command, when the negative relay should be open, if the negative relay detection circuit in this embodiment also determines that the negative relay is open, then the negative relay is open. If the negative relay detection circuit in this embodiment determines that the negative relay is closed, then there may be a problem of adhesion or short circuit in the negative relay.

[0069] The negative relay closed state detection circuit in this embodiment can control the opening and closing of the detection circuit through the setting of the opening and closing unit 10, provide better protection for the detection unit 20 through the setting of the protection circuit, output a detection signal through the setting of the detection unit 20, and collect the detection signal through the setting of the acquisition unit 30 to determine the closed state of the negative relay.

[0070] Embodiment 2

[0071] This embodiment relates to a vehicle, in which the negative relay closed state detection circuit in Embodiment 1 is provided.

[0072] The vehicle in this embodiment can detect the closed state of the negative relay by configuring the negative relay closed state detection circuit in Embodiment 1, so as to improve the use safety of the battery pack and thus improve the use quality of the whole vehicle.

[0073] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A negative pole relay energizing state detection circuit, used for detecting the energizing state of the negative pole relay of a battery pack, characterized in that: The detection circuit includes: An on-off unit, wherein an output terminal of the on-off unit is connected between the negative electrode relay and the load; A detection unit, wherein the input end of the detection unit is commonly connected to the output end of the opening and closing unit, the output end of the detection unit is grounded, and is used to output a detection signal; A collection unit, wherein the output end of the collection unit is connected to the input end of the on-off unit, the input end of the collection unit is connected to the detection unit, and is used to collect the detection signal to determine the pull-in state of the negative relay; When the acquisition unit does not acquire the detection signal, it is determined that the negative pole relay is disconnected; when the acquisition unit acquires the detection signal, it is determined that the negative pole relay is closed.

2. The negative pole relay energizing state detection circuit according to claim 1, characterized in that: The on-off unit includes a first resistor, a first optical coupler, a second resistor, a first transistor and a first diode; The input end of the first resistor is connected to the first power supply unit, the output end of the first resistor is connected to the input end of the light emitter of the first optocoupler, the output end of the light emitter of the first optocoupler is connected to the collector of the first triode, the base of the first triode is connected to the output end of the collection unit, and the emitter of the first triode is grounded; The input end of the photosensitive element of the first photocoupler is connected to the second power supply unit, the output end of the photosensitive element of the first photocoupler is connected to the first end of the second resistor, the second end of the second resistor is connected to the anode of the first diode, and the cathode of the first diode is connected to the output end of the start-stop unit.

3. The negative pole relay energizing state detection circuit according to claim 2, characterized in that: The first power supply unit is located at the low voltage side, and the second power supply unit is located at the high voltage side.

4. The negative pole relay energizing state detection circuit according to claim 2, characterized in that: The detection unit includes a second optical coupler and a third resistor; The input end of the light emitter of the second optical coupler is commonly connected to the output end of the on-off unit, and the output end of the light emitter of the second optical coupler is grounded; A first end of the third resistor is connected to a third power supply unit, a second end of the third resistor is connected to an input end of a photosensitive element of the second optical coupler, and an output end of the second optical coupler is grounded.

5. The negative pole relay energizing state detection circuit according to claim 4, characterized in that: The third power supply unit is located on the low voltage side.

6. The negative pole relay energizing state detection circuit according to claim 4, characterized in that: It also includes a protection unit, the input end of the protection unit is commonly connected to the output end of the opening and closing unit, the output end of the protection unit is commonly connected to the output end of the light emitter of the second optocoupler, and is used for overvoltage, overcurrent, reverse voltage and surge impact protection of the light emitter of the second optocoupler.

7. The negative pole relay energizing state detection circuit according to claim 6, characterized in that: The protection unit includes a first capacitor, a second capacitor, a fourth resistor, a fifth resistor, a sixth resistor, a second diode, a seventh resistor and a first voltage stabilizing diode; The first end of the first capacitor is connected to the output end of the on-off unit, the second end of the first capacitor is connected to the first end of the second capacitor, the second end of the second capacitor is connected to the output end of the light emitter of the second optical coupler, and is used for surge protection of the light emitter of the second optical coupler; The fourth resistor, the fifth resistor and the sixth resistor are connected in series in sequence, and are connected in series between the output end of the on-off unit and the input end of the light emitter of the second optical coupler, and are used for overcurrent protection of the light emitter of the second optical coupler; The second diode is connected in series between the fifth resistor and the sixth resistor, the anode of the second diode is connected to the second end of the fifth resistor, the cathode of the second diode is connected to the first end of the seventh resistor, and is used for reverse voltage protection of the light emitter of the second optical coupler; The first end of the seventh resistor is connected to the anode of the second diode, the second end of the seventh resistor is connected to the cathode of the first voltage-stabilizing diode, the anode of the first voltage-stabilizing diode is connected to the output end of the light-emitting device of the second optocoupler and is used for overvoltage protection of the light-emitting device of the second optocoupler, and the seventh resistor is used for overcurrent protection of the first voltage-stabilizing diode.

8. The negative pole relay energizing state detection circuit according to claim 4, characterized in that: The acquisition unit includes an eighth resistor, a ninth resistor and an MCU; The first end of the eighth resistor is commonly connected to the input end of the photosensitive element of the second optical coupler, and the second end of the eighth resistor is connected to the GPIO-0 port of the MCU; A first end of the ninth resistor is connected to the GPIO-1 port of the MCU, and a second end of the ninth resistor is connected to the input end of the on / off unit.

9. A vehicle, characterized in that: It comprises the negative pole relay energizing state detection circuit according to any one of claims 1 to 8.

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