Constant current driving circuit, device and vehicle

Abstract

The utility model relates to a kind of constant-current drive circuit, device and vehicle, wherein, the constant-current drive circuit includes: power supply, sampling circuit, adjustment module, control unit and load;Power supply is connected with sampling circuit and adjustment module, for providing working voltage;Sampling circuit is connected with load, for sampling loop current signal;Control unit is connected with adjustment module and sampling circuit, for according to loop current signal, the output voltage of control adjustment module to make the current through load keep stable.By the present application, the problem of high cost caused by complex circuit structure is solved, and constant-current drive is achieved through discrete devices, reducing the complexity of circuit structure, thereby effectively reducing the cost.

Description

Technical Field

[0001] This utility model relates to the field of electronic circuit technology, and in particular to a constant current drive circuit, device and vehicle. Background Technology

[0002] With the rapid development of vehicle intelligence, vehicles integrate a large number of electronic loads with stringent requirements for current stability, such as intelligent driving sensors or lighting devices like LED light strips. Their operational stability directly affects driving safety and the driving experience. However, in practical applications, the supply voltage is easily affected by factors such as battery charging and discharging fluctuations and electromagnetic interference. To monitor and ensure that the load operates in a constant current state in real time, existing constant current drive circuits often adopt an indirect constant current scheme that combines digital control with magnetic induction or voltage feedback. However, this method requires the integration of a full-bridge switching network, precision resonant elements, and complex digital control units, resulting in a complex circuit structure, a large number of components, and high costs.

[0003] There is currently no effective solution to the problem of high cost due to complex circuit structure in related technologies. Utility Model Content

[0004] Therefore, it is necessary to provide a constant current drive circuit, device, and vehicle to address the problem of high cost caused by complex circuit structures in existing technologies.

[0005] Firstly, this utility model provides a constant current driving circuit, which includes a power supply, a sampling circuit, an adjustment module, a control unit, and a load;

[0006] The power supply is connected to the sampling circuit and the adjustment module, and is used to provide the operating voltage;

[0007] The sampling circuit is connected to the load and is used to sample the loop current signal;

[0008] The control unit, connected to the adjustment module and the sampling circuit, is used to control the output voltage of the adjustment module according to the loop current signal so that the current flowing through the load remains stable.

[0009] In some of these embodiments, the adjustment module includes a field-effect transistor Q1 and a resistor R1;

[0010] One end of the resistor R1 is connected to the source of the field-effect transistor Q1; the other end of the resistor R1 is grounded.

[0011] The drain of the field-effect transistor Q1 is connected to the power supply and the sampling circuit;

[0012] The gate of the field-effect transistor Q1 is connected to the control unit.

[0013] In some embodiments, the adjustment module further includes a capacitor C1;

[0014] One end of the capacitor C1 is connected to the gate of the field-effect transistor Q1; the other end of the capacitor C1 is grounded.

[0015] In some embodiments, the adjustment module further includes a resistor R2;

[0016] One end of the resistor R2 is connected to the gate of the field-effect transistor Q1; the other end of the resistor R2 is connected to the control unit.

[0017] In some embodiments, the sampling circuit includes a resistor R3;

[0018] One end of the resistor R3 is connected to the power supply and the regulating module; the other end of the resistor R3 is connected to the load.

[0019] In some embodiments, the constant current drive circuit further includes an overcurrent protection module and an output control module; the overcurrent protection module includes the sampling circuit and transistor Q2;

[0020] The emitter of the transistor Q2 is connected to one end of the resistor R3;

[0021] The base of the transistor Q2 is connected to the other end of the resistor R3;

[0022] The collector of the transistor Q2 is connected to the output control module.

[0023] In some of these embodiments, the output control module includes a resistor R4 and a field-effect transistor Q3;

[0024] One end of the resistor R4 is connected to the gate of the field-effect transistor Q3 and the collector of the transistor Q2; the other end of the resistor R4 is connected to the control unit.

[0025] The source of the field-effect transistor Q3 is connected to the resistor R3;

[0026] The drain of the field-effect transistor Q3 is connected to the load.

[0027] In some of these embodiments, the load is an LED light.

[0028] Secondly, this utility model provides a constant current driving device, which includes the constant current driving circuit described in the first aspect above.

[0029] Thirdly, the present invention provides a vehicle, the vehicle including the constant current drive device described in the first aspect above.

[0030] Compared with related technologies, the constant current drive circuit, device, and vehicle provided in this utility model include a power supply, a sampling circuit, an adjustment module, a control unit, and a load. The power supply is connected to the sampling circuit and the adjustment module to provide the operating voltage. The sampling circuit is connected to the load to sample the loop current signal. The control unit is connected to the adjustment module and the sampling circuit to control the output voltage of the adjustment module according to the loop current signal to keep the current flowing through the load stable. This solves the problem of high cost caused by complex circuit structure, realizes constant current drive through discrete components, reduces circuit structure complexity, and thus effectively reduces costs.

[0031] Details of one or more embodiments of the present invention are set forth in the following drawings and description to make other features, objects and advantages of the present application more readily apparent. Attached Figure Description

[0032] Figure 1 This is a structural block diagram of a constant current drive circuit provided in an embodiment of this application;

[0033] Figure 2 This is a schematic diagram of an adjustment module provided in an embodiment of this application;

[0034] Figure 3 This is a schematic diagram of an overcurrent protection module and its connection relationship provided in an embodiment of this application;

[0035] Figure 4 This is a schematic diagram of the output control module and its connection relationship provided in an embodiment of this application;

[0036] Figure 5 This is a schematic diagram of a constant current drive circuit provided in a preferred embodiment of this application.

[0037] Reference numerals: 10, Power supply; 20, Overcurrent protection module; 21, Sampling circuit; 30, Adjustment module; 40, Control unit; 50, Load; 60, Output control module. Detailed Implementation

[0038] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0039] It should be noted that when a component is said to be "installed on" another component, it can be directly on the other component or it may be in a component that is centered on it. When a component is said to be "set on" another component, it can be directly set on the other component or it may also be in a component that is centered on it. When a component is said to be "fixed to" another component, it can be directly fixed to the other component or it may also be in a component that is centered on it.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "or / and" as used herein includes any and all combinations of one or more of the associated listed items.

[0041] This invention provides a constant current drive circuit. Figure 1 This is a structural block diagram of a constant current drive circuit according to an embodiment of the present invention, as shown below. Figure 1 As shown, the constant current drive circuit includes: a power supply 10, a sampling circuit 21, an adjustment module 30, a control unit 40, and a load 50;

[0042] The power supply 10 is connected to the sampling circuit 21 and the regulation module 30 to provide the operating voltage;

[0043] Sampling circuit 21, connected to load 50, is used to sample the loop current signal;

[0044] The control unit 40, connected to the adjustment module 30 and the sampling circuit 21, is used to control the output voltage of the adjustment module 30 according to the loop current signal so that the current flowing through the load 50 remains stable.

[0045] In this embodiment, the constant current drive circuit includes a power supply 10, a sampling circuit 21, an adjustment module 30, a control unit 40, and a load 50 (such as an LED). Specifically, the power supply 10 is connected to the sampling circuit 21 and the adjustment module 30 to provide the system's operating voltage; the sampling circuit 21 is also connected to the load 50, and the sampling circuit 21 can be a single or multiple resistors used to sample the loop current signal. Based on this, the power supply 10, the sampling circuit 21, and the load 50 are connected in sequence to form a current path, and the loop current signal is used to indicate the magnitude and change of the current in the current path.

[0046] The control unit 40 is connected to the adjustment module 30 and the sampling circuit 21. It is used to determine whether the current of the sampling circuit 21 fluctuates based on the real-time loop current signal. If the current fluctuates, the output voltage of the control module 30 changes accordingly to keep the current flowing through the load 50 stable.

[0047] The adjustment module 30 includes a field-effect transistor (FET) Q1 and a resistor R1. The FET Q1 can be an N-channel FET, a P-channel FET, etc. Taking an N-channel FET as an example... Figure 2 As shown, one end of resistor R1 is connected to the source of field-effect transistor Q1, and the other end of resistor R1 is grounded. The drain of field-effect transistor Q1 is connected to the power supply 10, and the gate of field-effect transistor Q1 is connected to the control unit 40. When the control module detects a fluctuation in the current of the sampling circuit 21 in real time, it controls the gate voltage of field-effect transistor Q1 according to the loop current signal to dynamically adjust the conduction degree of field-effect transistor Q1, thereby changing the output voltage of the adjustment module 30 to ensure that the current flowing through the load 50 remains stable, that is, to achieve the goal of constant output current. In other embodiments, the adjustment module 30 also includes capacitor C1 and resistor R2. One end of capacitor C1 is connected to the gate of field-effect transistor Q1, and the other end is grounded to ensure the stability of the switching control terminal of field-effect transistor Q1. One end of resistor R2 is connected to the gate of field-effect transistor Q1, and the other end is connected to the control unit 40 to provide current limiting protection.

[0048] With the rapid development of vehicle intelligence, vehicles integrate a large number of electronic loads with stringent requirements for current stability, such as intelligent driving sensors or lighting devices like LED light strips. Their operational stability directly affects driving safety and the driving experience. However, in practical applications, the supply voltage is easily affected by factors such as battery charging and discharging fluctuations and electromagnetic interference. To monitor and ensure that the load operates in a constant current state in real time, existing constant current drive circuits often adopt an indirect constant current scheme that combines digital control with magnetic induction or voltage feedback. However, this method requires the integration of a full-bridge switching network, precision resonant elements, and complex digital control units, resulting in a complex circuit structure, a large number of components, and high costs.

[0049] Compared to existing technologies, the constant current drive circuit in this application includes a power supply, a sampling circuit, an adjustment module, a control unit, and a load. The power supply, connected to the sampling circuit and the adjustment module, provides the operating voltage. The sampling circuit, connected to the load, samples the loop current signal. The control unit, connected to the adjustment module and the sampling circuit, controls the output voltage of the adjustment module based on the loop current signal to keep the current flowing through the load stable. Based on this, the circuit is built using discrete components. The control unit collects the current in the sampling circuit in real time to adjust the loop voltage instantly, thereby achieving the goal of constant current output. This solves the problem of high cost due to complex circuit structure, realizing constant current drive through discrete components, reducing circuit complexity, and thus effectively reducing costs.

[0050] In some of these embodiments, such as Figure 2 As shown, the adjustment module 30 includes a field-effect transistor Q1 and a resistor R1;

[0051] One end of resistor R1 is connected to the source of field-effect transistor Q1; the other end of resistor R1 is grounded.

[0052] The drain of the field-effect transistor Q1 is connected to the power supply 10 and the sampling circuit 21;

[0053] The gate of the field-effect transistor Q1 is connected to the control unit 40.

[0054] Specifically, the adjustment module 30 includes a field-effect transistor Q1 and a resistor R1. One end of the resistor R1 is connected to the source of the field-effect transistor Q1, and the other end is grounded to prevent the gate from being floating. The drain of the field-effect transistor Q1 is connected to the power supply 10 and the sampling circuit 21, and the gate of the field-effect transistor Q1 is connected to the control unit 40.

[0055] When a fluctuation in the current of the sampling circuit 21 is detected in real time, the control module controls the gate voltage of the field-effect transistor Q1 according to the loop current signal to dynamically adjust the conduction degree of the field-effect transistor Q1, thereby changing the output voltage of the adjustment module 30 to ensure that the current flowing through the load 50 remains stable.

[0056] In this embodiment, the adjustment module 30 includes a field-effect transistor Q1 and a resistor R1. One end of the resistor R1 is connected to the source of the field-effect transistor Q1, and the other end is connected to the control unit 40. The drain of the field-effect transistor Q1 is connected to the power supply 10 and the sampling circuit 21, and the gate is connected to the control unit 40, so that the circuit voltage value can be adjusted by the adjustment module 30 to achieve constant current drive.

[0057] In some embodiments, the adjustment module 30 further includes a capacitor C1;

[0058] One end of capacitor C1 is connected to the gate of field-effect transistor Q1; the other end of capacitor C1 is grounded.

[0059] In this embodiment, the adjustment module 30 further includes a capacitor C1, one end of which is connected to the gate of the field-effect transistor Q1, and the other end is grounded. It can be understood that capacitor C1 acts as a de-jitter capacitor, connected in parallel with resistor R1 to form an RC low-pass filter, which can filter out high-frequency noise in the gate drive signal of Q2, ensuring the stability of the switching control terminal of the field-effect transistor Q1.

[0060] In this embodiment, the adjustment module 30 is equipped with a capacitor C1. One end of the capacitor C1 is connected to the gate of the field-effect transistor Q1, and the other end is grounded, thereby improving the overall stability of the adjustment module 30 and helping to accurately control the state of the adjustment module 30.

[0061] In some embodiments, the adjustment module 30 further includes a resistor R2;

[0062] One end of resistor R2 is connected to the gate of field-effect transistor Q1; the other end of resistor R2 is connected to control unit 40.

[0063] In this embodiment, the adjustment module 30 further includes a resistor R2, one end of which is connected to the gate of the field-effect transistor Q1, and the other end is connected to the control unit 40. It is understood that the resistor R2 acts as a current-limiting resistor, preventing instantaneous voltage jumps at the gate of the field-effect transistor Q1, thus providing current-limiting protection, and also helping to stabilize the output voltage of the adjustment module 30.

[0064] In this embodiment, the adjustment module 30 is equipped with a resistor R2. One end of the resistor R2 is connected to the gate of the field-effect transistor Q1, and the other end is connected to the control unit 40 to achieve current limiting protection.

[0065] In some embodiments, the sampling circuit 21 includes a resistor R3;

[0066] One end of resistor R3 is connected to power supply 10 and regulating module 30; the other end of resistor R3 is connected to load 50.

[0067] Specifically, the sampling circuit 21 includes a resistor R3. One end of the resistor R3 is connected to the power supply 10 and the regulation module 30, and the other end is connected to the load 50. The control module collects the current of the resistor R3 in real time. If a fluctuation in the current of the resistor R3 is detected, the gate voltage of the field-effect transistor Q1 is controlled to dynamically adjust the conduction level of the field-effect transistor Q1, thereby changing the output voltage of the regulation module 30 to ensure that the current flowing through the load 50 remains stable.

[0068] In this embodiment, based on the real-time fluctuation of the current in resistor R3, the output voltage of the regulating module 30 is controlled to achieve real-time monitoring and ensure that the load 50 operates in a constant current state.

[0069] In some embodiments, the constant current drive circuit described above further includes an overcurrent protection module 20 and an output control module 60; the overcurrent protection module 20 includes a sampling circuit 21 and a transistor Q2;

[0070] The emitter of transistor Q2 is connected to one end of resistor R3;

[0071] The base of transistor Q2 is connected to the other end of resistor R3;

[0072] The collector of transistor Q2 is connected to the output control module 60.

[0073] In this embodiment, the constant current drive circuit further includes an overcurrent protection module 20 and an output control module 60. The overcurrent protection module 20 includes a sampling circuit 21 and a transistor Q2. Taking a PNP transistor as an example, ... Figure 3 As shown, in the overcurrent protection module 20, the emitter of transistor Q2 is connected to one end of resistor R3, the base of transistor Q2 is connected to the other end of resistor R3, and the collector of transistor Q2 is connected to the output control module 60. This allows the voltage drop across resistor R3 caused by the current to control the switching on and off of transistor Q2. In other embodiments, an NPN transistor can also be used.

[0074] Specifically, under normal operating conditions, transistor Q1 is cut off, and resistor R3 can limit the current. When the output is short-circuited to ground, the current flowing through resistor R3 is abnormal. At this time, transistor Q1 is turned on, controlling the output control module 60 to disconnect and cut off the power supply to load 50.

[0075] In this embodiment, the constant current drive circuit also includes an overcurrent protection module 20 and an output control module 60. The overcurrent protection module 20 includes a sampling circuit 21 and a transistor Q2. The emitter of the transistor Q2 is connected to one end of the resistor R3, the base of the transistor Q2 is connected to the other end of the resistor R3, and the collector of the transistor Q2 is connected to the output control module 60. Thus, in the event of an abnormal current in the resistor R3, the power supply to the load 50 can be cut off in time. The hardware implements overcurrent control, significantly improves the response speed, ensures the real-time performance of overcurrent protection, and does not rely on the control unit or program to operate, thus having high reliability.

[0076] In some embodiments, the output control module 60 includes a resistor R4 and a field-effect transistor Q3;

[0077] One end of resistor R4 is connected to the gate of field-effect transistor Q3 and the collector of transistor Q2; the other end of resistor R4 is connected to control unit 40.

[0078] The source of the field-effect transistor Q3 is connected to the resistor R3;

[0079] The drain of the field-effect transistor Q3 is connected to the load 50.

[0080] Specifically, the output control module 60 includes a resistor R4 and a field-effect transistor Q3. Taking a P-channel field-effect transistor as an example, ... Figure 4 As shown, one end of resistor R4 is connected to the gate of field-effect transistor Q3 and the collector of transistor Q2, and the other end of resistor R4 is connected to control unit 40. The source of field-effect transistor Q3 is connected to resistor R3, and the drain of field-effect transistor Q3 is connected to load 50. In other embodiments, an N-channel field-effect transistor can also be used.

[0081] In the event of an abnormal current in resistor R3 due to a short circuit to ground at the output, transistor Q1 conducts, thereby controlling the field-effect transistor Q3 in the output control module 60 to turn off, thus cutting off the power supply to load 50. It can be understood that this embodiment utilizes the characteristics of the collector-emitter (CE) voltage of the transistor to control the switching on and off of the field-effect transistor Q3 in the output control module 60 when the circuit experiences overcurrent.

[0082] It should be noted that when the control unit 40 adjusts the output voltage of the regulating module 30 to achieve constant output current, it simultaneously outputs a corresponding voltage to the resistor R4 to ensure that the voltage difference between the gate and source (GS) of the field-effect transistor Q3 is stable at a preset fixed value, thereby protecting the field-effect transistor Q3 from being damaged by high voltage breakdown.

[0083] In this embodiment, the output control module 60 is composed of a resistor R4 and a field-effect transistor Q3. One end of the resistor R4 is connected to the gate of the field-effect transistor Q3 and the collector of the transistor Q2, and the other end is connected to the control unit 40. The source of the field-effect transistor Q3 is connected to the resistor R3, and the drain of the field-effect transistor Q3 is connected to the load 50. Overcurrent control is achieved through a hardware self-triggered protection mechanism, which has a fast response speed and provides timely overcurrent protection.

[0084] The present embodiment will now be described and illustrated through preferred embodiments.

[0085] Figure 5 This is a schematic diagram of a constant current drive circuit provided in a preferred embodiment of this application, as shown below. Figure 5 As shown, the constant current drive circuit includes: a power supply 10, an adjustment module 30, a control unit 40, an overcurrent protection module 20, an output control module 60, and a load 50, where the load 50 is an LED light. The power supply 10 is connected to the overcurrent protection module 20 and the adjustment module 30; the overcurrent protection module 20 is connected to the load 50 via the output control module 60; and the control unit 40 is connected to the adjustment module 30 and the sampling circuit 21.

[0086] Specifically, the adjustment module 30 includes a field-effect transistor Q1, resistors R1 and R2, and capacitor C1, which is a de-jitter capacitor. The field-effect transistor Q1 is an N-channel field-effect transistor. The source of the field-effect transistor Q1 is connected to resistor R1, the drain of the field-effect transistor Q1 is connected to the power supply 10 and the overcurrent protection module 20, and the gate of the field-effect transistor Q1 is connected to the control unit 40 through resistor R2.

[0087] When the control module detects fluctuations in the current of resistor R1 in real time, it controls the gate voltage of the field-effect transistor Q1 to dynamically adjust the conduction level of the field-effect transistor Q1, thereby changing the output voltage of the adjustment module 30 to ensure that the current flowing through the load 50 remains stable, that is, the goal of constant output current is achieved by adjusting the circuit voltage.

[0088] The overcurrent protection module 20 includes a sampling circuit 21 and a transistor Q2, which is a PNP transistor. In the overcurrent protection module 20, the emitter of transistor Q2 is connected to one end of resistor R3, the base of transistor Q2 is connected to the other end of resistor R3, and the collector of transistor Q2 is connected to the gate of field-effect transistor Q3 in the output control module 60. The output control module 60 also includes a resistor R4, one end of which is connected to the gate of field-effect transistor Q3 and the collector of transistor Q2, and the other end is connected to the control unit 40. The source of field-effect transistor Q3 is connected to resistor R3, and the drain of field-effect transistor Q3 is connected to the load 50.

[0089] Based on the above connection relationship, under normal operating conditions, transistor Q1 is cut off, and resistor R3 can limit current. When a short circuit to ground causes an abnormal current in resistor R3, transistor Q1 turns on, controlling the field-effect transistor Q3 in the output control module 60 to turn off, thereby cutting off the power supply to load 50. It can be understood that this embodiment utilizes the characteristics of the collector and emitter (CE) conduction voltage values ​​of the transistor to control the switching of the field-effect transistor Q3 in the output control module 60 when the circuit experiences overcurrent. This hardware-triggered protection mechanism achieves overcurrent control, significantly improving response speed and ensuring real-time overcurrent protection. Furthermore, it does not rely on the control unit or program operation, thus exhibiting high reliability.

[0090] It should be further explained that when the control unit 40 adjusts the output voltage of the regulating module 30 to achieve constant output current, it simultaneously outputs a corresponding voltage to the resistor R4 to ensure that the voltage difference between the gate and source of the field-effect transistor Q3 is stable at a preset fixed value, thereby protecting the field-effect transistor Q3 from being damaged by high voltage breakdown.

[0091] In this embodiment, a power supply, a regulating module, a control unit, an overcurrent protection module, an output control module, and a load are connected. The power supply is connected to the overcurrent protection module and the regulating module. The overcurrent protection module is connected to the load through the output control module. The control unit is connected to the regulating module and the sampling circuit. In this way, a constant current drive circuit is built using discrete components. The constant current operation of the load is achieved through closed-loop control, which effectively reduces costs. At the same time, the hardware implements overcurrent control, improves response speed, and achieves timely overcurrent protection.

[0092] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0093] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A constant current drive circuit, characterized in that, The constant current drive circuit includes a power supply, a sampling circuit, an adjustment module, a control unit, and a load; The power supply is connected to the sampling circuit and the adjustment module, and is used to provide the operating voltage; The sampling circuit is connected to the load and is used to sample the loop current signal; The control unit, connected to the adjustment module and the sampling circuit, is used to control the output voltage of the adjustment module according to the loop current signal so that the current flowing through the load remains stable.

2. The constant current drive circuit according to claim 1, characterized in that, The adjustment module includes a field-effect transistor Q1 and a resistor R1; One end of the resistor R1 is connected to the source of the field-effect transistor Q1; the other end of the resistor R1 is grounded. The drain of the field-effect transistor Q1 is connected to the power supply and the sampling circuit; The gate of the field-effect transistor Q1 is connected to the control unit.

3. The constant current drive circuit according to claim 2, characterized in that, The adjustment module also includes a capacitor C1; One end of the capacitor C1 is connected to the gate of the field-effect transistor Q1; the other end of the capacitor C1 is grounded.

4. The constant current drive circuit according to claim 3, characterized in that, The adjustment module also includes a resistor R2; One end of the resistor R2 is connected to the gate of the field-effect transistor Q1; the other end of the resistor R2 is connected to the control unit.

5. The constant current drive circuit according to claim 1, characterized in that, The sampling circuit includes resistor R3; One end of the resistor R3 is connected to the power supply and the regulating module; the other end of the resistor R3 is connected to the load.

6. The constant current drive circuit according to claim 5, characterized in that, The constant current drive circuit also includes an overcurrent protection module and an output control module; the overcurrent protection module includes the sampling circuit and transistor Q2. The emitter of the transistor Q2 is connected to one end of the resistor R3; The base of the transistor Q2 is connected to the other end of the resistor R3; The collector of the transistor Q2 is connected to the output control module.

7. The constant current drive circuit according to claim 6, characterized in that, The output control module includes a resistor R4 and a field-effect transistor Q3; One end of the resistor R4 is connected to the gate of the field-effect transistor Q3 and the collector of the transistor Q2; the other end of the resistor R4 is connected to the control unit. The source of the field-effect transistor Q3 is connected to the resistor R3; The drain of the field-effect transistor Q3 is connected to the load.

8. The constant current drive circuit according to any one of claims 1 to 7, characterized in that, The load is an LED light.

9. A constant current drive device, characterized in that, The device includes a constant current drive circuit as described in any one of claims 1 to 8.

10. A vehicle, characterized in that, The vehicle includes the constant current drive device as described in claim 9.

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