Vehicle-mounted nickel-metal hydride battery controller

Abstract

The utility model discloses a vehicle-mounted nickel-metal hydride battery controller, which has a unique nickel-metal hydride battery charging and discharging control path, can supply power to a load and charge a nickel-metal hydride battery when the voltage of a storage battery of a whole vehicle is normal, and can switch a power supply and control the nickel-metal hydride battery to temporarily supply power to the load when the storage battery of the whole vehicle is powered down. When the temporary power supply is finished or the preset discharge time is reached, the discharge path of the nickel-metal hydride battery is cut off to realize controllable discharge; the MCU, the charging driving chip and other discrete devices are adopted to form a power supply, charging and discharging integrated circuit, the number of the devices is small, and the cost is low; the shell base comprises two cavities which are used for placing the nickel-metal hydride battery pack and the circuit board respectively, and the circuit board is placed on one side of the nickel-metal hydride battery pack, so that the size of the controller is greatly compressed, and the controller is suitable for the limited arrangement space of an automobile; charging and discharging information of different stages is represented through the flicker frequency and the on-off state of one indicator lamp, and the cost of the controller is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of vehicle-mounted batteries, relates to the discharge of vehicle-mounted batteries, and specifically relates to a vehicle-mounted nickel-hydrogen battery controller. Background Art

[0002] In recent years, nickel-metal hydride batteries have attracted more and more attention from the automotive industry due to their excellent charging and discharging characteristics and declining costs. 2 Compared with traditional nickel-cadmium batteries, nickel-metal hydride batteries eliminate the pollution of cadmium to the environment, increase the capacity by 30%, can achieve fast charging, have a longer service life and a lower weight. In addition, nickel-metal hydride batteries have an excellent operating temperature range, with the lowest operating temperature reaching -40°C, which is much lower than the lower operating temperature of conventional lithium-ion batteries, lithium iron phosphate batteries and lead-acid batteries. Therefore, for automotive applications, nickel-metal hydride batteries can better meet the working requirements in harsh environments and extreme climates.

[0003] Taking passenger cars as an example, the various electronic control units (ECUs) currently on board are usually powered directly by the vehicle's 12V low-voltage lead-acid battery. When the vehicle is turned off and the power is cut off, the ECU will also lose its power source directly. In addition, the ECU will not work when the car encounters extremely cold weather, the vehicle is severely collided causing damage to the vehicle battery, or the power supply is accidentally lost. This will cause serious problems for some ECUs involving data security (such as data acquisition units for autonomous driving), such as data loss, incomplete or even erroneous records, abnormal processor data operations, memory abnormalities, and even the possibility of formatting, which will lead to problems such as failure to record extreme working conditions or accident scenes and determination of legal liability. Utility Model Content

[0004] In view of the above problems, the main purpose of the utility model is to design an on-board nickel-metal hydride battery controller to solve the problem of controller power failure directly caused by an emergency situation in a passenger car when powered by existing batteries.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] A vehicle-mounted nickel-hydrogen battery controller comprises a housing, a circuit board and a nickel-hydrogen battery pack arranged in the housing, wherein the circuit board is connected to the nickel-hydrogen battery pack via a connector, and a control circuit is arranged on the circuit board;

[0007] A battery cavity and a circuit board cavity are arranged inside the housing, the circuit board is arranged in the circuit board cavity, and the nickel-metal hydride battery pack is arranged in the battery cavity;

[0008] An input interface, an output interface and an indicator light port are provided on the outer side of the corresponding circuit board cavity; the circuit board includes an input port, an output port and an indicator light, the input port corresponds to the input interface, the output port corresponds to the output interface, and the indicator light corresponds to the indicator light port.

[0009] As a further description of the utility model, the housing comprises a housing base and a housing cover, and the housing cover is fixed on top of the housing base by screws to form a cavity;

[0010] The battery cavity and the circuit board cavity are arranged in the inner cavity of the housing base.

[0011] As a further description of the utility model, the control circuit includes a current direction control unit, and the current direction control unit is composed of three diodes, namely a first diode, a second diode, and a third diode;

[0012] The input end of the first diode is connected to the input port, the output end of the first diode is respectively connected to the input end of the second diode, the output end and the output port of the third diode, and the input end of the second diode is connected to the output end of the third diode.

[0013] As a further description of the present utility model, the control circuit further includes a charging unit, a feedback unit, and a microcontroller unit;

[0014] The output end of the second diode is connected to the charging unit, and the current direction is from the input port to the charging unit; the input end of the third diode is connected to the feedback unit through the microcontroller unit, and the current direction is from the feedback unit to the output port.

[0015] As a further description of the present utility model, the charging unit includes a first enhanced PMOS tube, an enhanced NMOS tube, a capacitor, and an inductor connected in sequence, the other end of the inductor is connected between the first enhanced PMOS tube and the enhanced NMOS tube, and the first enhanced PMOS tube is connected to the output end of the second diode.

[0016] As a further description of the utility model, the feedback unit includes a current sampling resistor, a voltage sampling resistor, a nickel-hydrogen battery, and a temperature sampling resistor connected to the nickel-hydrogen battery;

[0017] The current sampling resistor, the voltage sampling resistor, and the nickel-hydrogen battery are respectively connected to the charging unit and the microcontroller unit, and the temperature sampling resistor is connected to the microcontroller unit;

[0018] One end of the current sampling resistor is connected between the inductor and the capacitor, and the other end is respectively connected to the voltage sampling resistor, the nickel-hydrogen battery, and the microcontroller unit. Two voltage sampling resistors are provided, namely a first voltage sampling resistor and a second voltage sampling resistor.

[0019] As a further description of the utility model, the microcontroller unit includes an MCU, and an input sampling circuit and an output control circuit connected to the MCU, and the temperature sampling resistor outputs the temperature sample of the nickel-metal hydride battery to the MCU;

[0020] The input sampling circuit includes a voltage-dividing resistor for input port sampling, and the output control circuit includes a second enhanced PMOS tube and a first NPN transistor for controlling discharge, and a second NPN transistor for controlling the indicator light;

[0021] The base of the first NPN transistor is connected to the MCU, the collector is connected to the gate of the second enhancement mode PMOS transistor, the source of the second enhancement mode PMOS transistor is connected to the feedback unit, and the drain is connected to the input end of the third diode;

[0022] The base of the second NPN transistor is connected to the MCU, and the collector is connected to the indicator light.

[0023] As a further description of the present utility model, the control circuit also includes a charging drive unit, which is composed of a charging drive chip, which outputs PWM1 and PWM2 signals to the first enhanced PMOS tube and enhanced NMOS tube in the charging unit, and outputs PWM3 signal to the second NPN transistor of the MCU;

[0024] The input end of the charging drive unit is connected to the current sampling resistor and the voltage sampling resistor, and receives the output current sampling and output voltage sampling signals of the feedback unit;

[0025] The input end of the charging drive unit is also connected to the MCU of the microcontroller unit to receive communication and control signals from the microcontroller unit.

[0026] Compared with the prior art, the technical effects of the utility model are:

[0027] The utility model provides a vehicle-mounted nickel-hydrogen battery controller with a unique nickel-hydrogen battery charge and discharge control path, which can realize powering the load and charging the nickel-hydrogen battery at the same time when the battery voltage of the whole vehicle is normal, switching the power supply and controlling the nickel-hydrogen battery to temporarily power the load when the battery voltage of the whole vehicle is off, and cutting off the discharge path of the nickel-hydrogen battery when the temporary power supply ends or the preset discharge time is reached, so as to realize controllable discharge; an MCU, a driving charging driver chip and other discrete devices are adopted to form a power supply, charging and discharging integrated circuit, with a small number of devices and a low cost; and a shell base comprises two cavities, in which the nickel-hydrogen battery pack and the circuit board are respectively placed, and the circuit board is placed on one side of the nickel-hydrogen battery pack, so that the volume of the controller is extremely compressed, and it is suitable for the limited layout space of the car; the charging and discharging information of different stages is indicated by the flashing frequency and the on and off state of an indicator light, so as to reduce the cost of the controller. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is an exploded view of the overall structure of the utility model;

[0029] Figure 2 This is a rear view of the overall structure of the utility model after assembly;

[0030] Figure 3 This is a top view of the inner cavity of the housing base of the utility model;

[0031] Figure 4 It is an assembly side view of the utility model;

[0032] Figure 5 It is a schematic diagram of the connection relationship between the control circuit of the utility model and the input port, the output port, and the nickel-hydrogen battery pack;

[0033] Figure 6 This is a control circuit schematic diagram of the utility model.

[0034] In the figure, 1. shell, 11. battery cavity, 12. circuit board cavity, 13. input interface, 14. output interface, 15. indicator light port, 16. shell base, 17. shell cover, 2. circuit board, 21. input port, 22. output port, 23. indicator light, 3. nickel-metal hydride battery pack, 4. connector. DETAILED DESCRIPTION

[0035] The utility model is described in detail below with reference to the accompanying drawings:

[0036] In one embodiment of the utility model, a vehicle-mounted nickel-metal hydride battery controller is disclosed, such as Figure 1-6As shown, it includes a shell 1 and a circuit board 2 and a nickel-metal hydride battery pack 3 arranged in the shell 1, the circuit board 2 is connected to the nickel-metal hydride battery pack 3 through a connector 4, and the circuit board 2 is provided with a control circuit, the control circuit realizes the selection of the power supply path, and the charging and discharging control of the nickel-metal hydride battery pack 3; specifically, a battery cavity 11 and a circuit board cavity 12 are arranged inside the shell 1, the circuit board 2 is arranged in the circuit board cavity 12, and the nickel-metal hydride battery pack 3 is arranged in the battery cavity 11; an input interface 13, an output interface 14 and an indicator light port 15 are provided on the outer side corresponding to the circuit board cavity 12; the circuit board 2 includes an input port 21 (KL30 port, GND), an output port 22 (KL30_b port, GND) and an indicator light 23 (LED indicator light), the input port 21 corresponds to the input interface 13, the output port 22 corresponds to the output interface 14, and the indicator light 23 corresponds to the indicator light port 15.

[0037] It should also be noted that, in this embodiment, the above-mentioned shell includes a shell base 16 and a shell cover 17, and the shell cover 17 is fixed on the top of the shell base 16 by screws to form a cavity; the battery cavity 11 and the circuit board cavity 12 are arranged in the inner cavity of the shell base 16.

[0038] In this embodiment, the control circuit includes: a current direction control unit ①, a charging drive unit ②, a charging unit ③, a feedback unit ④, and a microcontroller unit ⑤.

[0039] In this embodiment, a specific analysis is made on the components and connection relationships of the above-mentioned units, as follows:

[0040] 1. Current direction control unit: composed of three diodes, namely a first diode D1, a second diode D2, and a third diode D3; the input end of the first diode D1 is connected to the input port 21, the output end of the first diode D1 is respectively connected to the input end of the second diode D2, the output end of the third diode D3 and the output port 22, and the input end of the second diode D2 is connected to the output end of the third diode D3.

[0041] In addition, the output end of the second diode D2 is connected to the charging unit, and the current direction is from the input port to the charging unit; the input end of the third diode D3 is connected to the feedback unit through the microcontroller unit, and the current direction is from the feedback unit to the output port 22.

[0042] When the KL30 input port 21 is connected to the vehicle battery, the current flows into the KL30_b output port 22 through the first diode D1 and is directly given to the rear-end load for use. At the same time, the current flows into the charging unit through the second diode D2. When the vehicle battery loses power, the current flows from the nickel-metal hydride battery pack 3 through the third diode D3 and is given to the KL30_b output port 22 for use by the rear-end load.

[0043] 2. Charging unit: comprising a first enhanced PMOS transistor Q1, an enhanced NMOS transistor Q2, a capacitor C1, and an inductor L1 connected in sequence, the other end of the inductor L1 is connected between the first enhanced PMOS transistor Q1 and the enhanced NMOS transistor Q2, and the first enhanced PMOS transistor Q1 is connected to the output end of the second diode D2.

[0044] The charging unit of this embodiment controls the alternate switching of the first enhancement mode PMOS transistor Q1 and the enhancement mode NMOS transistor Q2 through the received PWM control signal to achieve power switching.

[0045] 3. Feedback unit: including a current sampling resistor R1, a voltage sampling resistor, a nickel-hydrogen battery, and a temperature sampling resistor NTC connected to the nickel-hydrogen battery; the current sampling resistor R1, the voltage sampling resistor, and the nickel-hydrogen battery are respectively connected to the charging unit and the microcontroller unit, and the temperature sampling resistor NTC is connected to the microcontroller unit.

[0046] One end of the current sampling resistor R1 is connected between the inductor L1 and the capacitor C1, and the other end is respectively connected to the voltage sampling resistor, the nickel-hydrogen battery, and the microcontroller unit. Two voltage sampling resistors are provided, namely a first voltage sampling resistor R7 and a second voltage sampling resistor R8.

[0047] Realize the feedback of charging current, charging voltage, NiMH battery temperature and other information to the microcontroller unit.

[0048] 4. Microcontroller unit: including MCU, and input sampling circuit and output control circuit connected to MCU, the temperature sampling resistor NTC outputs the nickel-metal hydride battery temperature sample to MCU; specifically, the input sampling circuit includes voltage-dividing resistors R5 and R6 for sampling the KL30 input port 21, the output control circuit includes a second enhanced PMOS tube Q3 and a first NPN transistor Q4 for controlling discharge, and a second NPN transistor Q5 for controlling the indicator light D5;

[0049] Among them, the base of the first NPN transistor Q4 is connected to the MCU, the collector is connected to the gate of the second enhancement PMOS transistor Q3, the source of the second enhancement PMOS transistor Q3 is connected to the feedback unit, and the drain is connected to the input end of the third diode D3; the base of the second NPN transistor Q5 is connected to the MCU, and the collector is connected to the indicator light D5.

[0050] It should be noted that the output control circuit also includes resistors R3 and R4 arranged at the first NPN transistor Q4, a resistor R2 arranged at the second enhancement PMOS transistor Q3, resistors R9 and R10 arranged at the second NPN transistor Q5, and a resistor R11 arranged at the indicator light D5.

[0051] 5. Charging drive unit: composed of a charging drive chip, which outputs PWM1 and PWM2 signals to the first enhanced PMOS tube Q1 and enhanced NMOS tube Q2 in the charging unit, and outputs PWM3 signal to the second NPN transistor Q5 of the MCU; the input end of the charging drive unit is connected to the current sampling resistor R1 and the voltage sampling resistors R7 and R8, receives the output current sampling and output voltage sampling signals of the feedback unit, and realizes dual closed-loop control of current and voltage; the input end of the charging drive unit is also connected to the MCU of the microcontroller unit to receive the communication and control signals of the microcontroller unit.

[0052] Specifically, through the electronic devices and their connection relationships provided in the above-mentioned units, the charging current, charging voltage and other information are fed back to the charging drive unit and the microcontroller unit in real time through the feedback unit, thereby realizing closed-loop control while preventing abnormalities such as overcharging and overtemperature of the nickel-hydrogen battery.

[0053] In this embodiment, the MCU of the microcontroller unit obtains the KL30 through sampling, and determines the charging or discharging strategy to be executed in real time. When the KL30 input port 21 is connected to the battery of the whole vehicle and the KL30 voltage is within the range of the whole vehicle, the MCU controls the charging drive unit through the communication control signal line, and the charging drive unit outputs a PWM signal to the charging unit to charge the nickel-hydrogen battery. At the same time, the MCU outputs a PWM3 signal to the second NPN transistor Q5 to realize the flashing of the indicator light D5. The duty cycle frequency of PWM3 changes according to the different charging states, so as to facilitate the human eye to observe the working state of the current controller.

[0054] When the NiMH battery is low in the early stage of charging, the charging driver chip is in fast charging mode and outputs a 0.5C charging current. At the same time, the MCU outputs a PWM3 signal with a frequency of 1Hz to control the LED indicator D5 to flash once per second; when the NiMH battery is high in the middle and late stages of charging, the charging driver chip is in slow charging mode and outputs a 0.1C charging current. At the same time, the MCU outputs a PWM3 signal with a frequency of 0.25Hz to control the LED indicator D5 to flash once every 4 seconds; when the NiMH battery is close to full charge in the late stage of charging, the charging driver chip is in trickle mode. At the same time, the MCU outputs a PWM3 signal with a frequency of 0.125Hz to control the LED indicator D5 to flash once every 8 seconds; when a charging cycle is completed, the MCU outputs a normally high level through resistor R9 to control the LED indicator D5 to be always on to indicate that charging is complete.

[0055] When the vehicle battery loses power, the MCU controls the charging drive unit to shut down the charging operation through the communication control signal line, and outputs a high level to the base of the first NPN transistor Q4 through the resistor R3, thereby making the gate of the second enhancement mode PMOS tube Q3 at a low level, so that the second enhancement mode PMOS tube Q3 is turned on, so that the nickel-hydrogen battery current is passed from the second enhancement mode PMOS tube Q3 to the third diode D3 and given to the KL30_b output port 22 for use by the rear-end load, thereby maintaining the temporary power supply of the load ECU.

[0056] When the temporary power supply ends or the preset discharge time is reached, the MCU outputs a low level to the base of the first NPN transistor Q4 through the resistor R3, thereby making the gate of the second enhancement PMOS transistor Q3 at a high level, thereby turning off the second enhancement PMOS transistor Q3 and cutting off the discharge path of the nickel-hydrogen battery, thereby achieving controllable discharge and preventing excessive discharge of the battery from affecting the battery life. At the same time, the MCU outputs a normally low level through the resistor R9, controlling the LED indicator D5 to be normally off, indicating that the discharge is completed.

[0057] Taking the 12V system of a car as an example, in the utility model, the charging driver chip can select a current source control chip suitable for nickel-metal hydride batteries, such as Maxim MAX1640; the microcontroller can select a general-purpose MCU of automotive grade, such as NXP S32K344; the nickel-metal hydride battery can select a combined battery pack of automotive grade, such as EPT AA1200mAh-S×10; the PMOS tubes Q1 and Q3 can respectively select power MOS tubes with a drain-source withstand voltage of -40V, such as PANJIT PJA3449AU; the NMOS tube Q2 can select a power MOS tube with a drain-source withstand voltage of 40V, such as PANJIT PJA3448AU; the transistors Q4 and Q5 can select NPN-type general-purpose transistors, such as NexperiaBC847-Q; the diodes D1, D2, and D3 can select Schottky diodes, such as Nexperia PMEG100T50ELP-Q; the LED indicator D5 can select a light-emitting diode, such as VISHAY TLLG440; resistor R1 can be a high-precision sampling resistor, such as VikingAR06DTC; resistors R2~R11 can be general-purpose thick film resistors, such as Yageo AC0402FR series; temperature sampling resistor NTC can be a vehicle-mounted thermistor, such as Murata NCU18XH103F6SRB; capacitor C1 can be a voltage-stabilizing capacitor, such as Murata GCM32EC71E226KE36L; inductor L1 can be a power inductor, such as KOHER MDA1040.

[0058] Through the above content, the technical solution of the utility model is disclosed. Compared with the prior art, the utility model has the following advantages:

[0059] 1. The unique nickel-hydrogen battery charge and discharge control path of the utility model can realize power supply to the load and charge the nickel-hydrogen battery at the same time when the battery voltage of the whole vehicle is normal; when the battery of the whole vehicle loses power, the power supply is switched and the nickel-hydrogen battery is controlled to temporarily power the load; when the temporary power supply ends or the preset discharge time is reached, the discharge path of the nickel-hydrogen battery is cut off to realize controllable discharge and avoid excessive discharge of the battery affecting the battery life;

[0060] 2. The utility model uses MCU, charging driver chip (IC) and other discrete devices to form a power supply, charging and discharging integrated circuit, with a small number of devices and low cost;

[0061] 3. The utility model has a compact structural design. The housing base includes two cavities, which are used to place the nickel-metal hydride battery pack and the circuit board respectively. The circuit board is placed on one side of the nickel-metal hydride battery pack, which greatly compresses the volume of the controller and is suitable for the limited layout space of the car;

[0062] 4. The utility model indicates the charging and discharging status through the flashing frequency of an indicator light. When the nickel-hydrogen battery is fast charged, the flashing frequency of the light is high, and when the nickel-hydrogen battery is slowly charged, the flashing frequency of the light is low. When the nickel-hydrogen battery is fully charged, the light is always on, and when the nickel-hydrogen battery is fully discharged, the light is always off, thereby realizing multiple status indications and reducing the controller cost.

[0063] The above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Other modifications or equivalent substitutions made to the technical solution of the utility model by ordinary technicians in this field should be included in the scope of the claims of the utility model as long as they do not depart from the spirit and scope of the technical solution of the utility model.

Claims

1. A vehicle-mounted nickel-metal hydride battery controller, characterized in that: It comprises a housing, a circuit board and a nickel-metal hydride battery pack arranged in the housing, wherein the circuit board is connected to the nickel-metal hydride battery pack via a connector, and a control circuit is arranged on the circuit board; A battery cavity and a circuit board cavity are arranged inside the housing, the circuit board is arranged in the circuit board cavity, and the nickel-metal hydride battery pack is arranged in the battery cavity; An input interface, an output interface and an indicator light port are provided on the outer side of the corresponding circuit board cavity; the circuit board includes an input port, an output port and an indicator light, the input port corresponds to the input interface, the output port corresponds to the output interface, and the indicator light corresponds to the indicator light port.

2. The vehicle-mounted nickel-metal hydride battery controller according to claim 1, characterized in that: The housing comprises a housing base and a housing cover, wherein the housing cover is fixed on the housing base by screws to form a cavity; The battery cavity and the circuit board cavity are arranged in the inner cavity of the housing base.

3. The vehicle-mounted nickel-metal hydride battery controller according to claim 1, characterized in that: The control circuit includes a current direction control unit, which is composed of three diodes, namely a first diode, a second diode, and a third diode; The input end of the first diode is connected to the input port, the output end of the first diode is respectively connected to the input end of the second diode, the output end and the output port of the third diode, and the input end of the second diode is connected to the output end of the third diode.

4. The vehicle-mounted nickel-metal hydride battery controller according to claim 3, characterized in that: The control circuit also includes a charging unit, a feedback unit, and a microcontroller unit; The output end of the second diode is connected to the charging unit, and the current direction is from the input port to the charging unit; the input end of the third diode is connected to the feedback unit through the microcontroller unit, and the current direction is from the feedback unit to the output port.

5. The vehicle-mounted nickel-metal hydride battery controller according to claim 4, characterized in that: The charging unit includes a first enhanced PMOS tube, an enhanced NMOS tube, a capacitor, and an inductor connected in sequence, the other end of the inductor is connected between the first enhanced PMOS tube and the enhanced NMOS tube, and the first enhanced PMOS tube is connected to the output end of the second diode.

6. The vehicle-mounted nickel-metal hydride battery controller according to claim 5, characterized in that: The feedback unit includes a current sampling resistor, a voltage sampling resistor, a nickel-hydrogen battery, and a temperature sampling resistor connected to the nickel-hydrogen battery; The current sampling resistor, the voltage sampling resistor, and the nickel-hydrogen battery are respectively connected to the charging unit and the microcontroller unit, and the temperature sampling resistor is connected to the microcontroller unit; One end of the current sampling resistor is connected between the inductor and the capacitor, and the other end is respectively connected to the voltage sampling resistor, the nickel-hydrogen battery, and the microcontroller unit. Two voltage sampling resistors are provided, namely a first voltage sampling resistor and a second voltage sampling resistor.

7. The vehicle-mounted nickel-metal hydride battery controller according to claim 6, characterized in that: The microcontroller unit includes an MCU, and an input sampling circuit and an output control circuit connected to the MCU, and the temperature sampling resistor outputs the temperature sample of the nickel-hydrogen battery to the MCU; The input sampling circuit includes a voltage-dividing resistor for input port sampling, and the output control circuit includes a second enhanced PMOS tube and a first NPN transistor for controlling discharge, and a second NPN transistor for controlling the indicator light; The base of the first NPN transistor is connected to the MCU, the collector is connected to the gate of the second enhancement mode PMOS transistor, the source of the second enhancement mode PMOS transistor is connected to the feedback unit, and the drain is connected to the input end of the third diode; The base of the second NPN transistor is connected to the MCU, and the collector is connected to the indicator light.

8. The vehicle-mounted nickel-metal hydride battery controller according to claim 7, characterized in that: The control circuit also includes a charging drive unit, which is composed of a charging drive chip. The charging drive chip outputs PWM1 and PWM2 signals to a first enhanced PMOS transistor and an enhanced NMOS transistor in the charging unit, and outputs a PWM3 signal to a second NPN transistor of the MCU; The input end of the charging drive unit is connected to the current sampling resistor and the voltage sampling resistor, and receives the output current sampling and output voltage sampling signals of the feedback unit; The input end of the charging drive unit is also connected to the MCU of the microcontroller unit to receive communication and control signals from the microcontroller unit.

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