Control circuit for reducing charging surge current

Abstract

The utility model relates to the technical field of battery charging, and discloses a control circuit for reducing charging surge current, which comprises a power supply unit, a detection unit, a processing unit and a control unit. The detection unit detects the voltage of the battery and feeds back a detection signal to the processing unit, the processing unit outputs a corresponding control signal to the control unit according to the detection signal, and the control unit adjusts the output voltage according to the control signal to enable the output voltage to be the same as the voltage of the battery. And the processing unit controls the switch loop in the power supply unit to be switched on so as to charge the battery. According to the control circuit for reducing the charging surge current disclosed by the utility model, the output voltage and the battery voltage are controlled within a relatively small voltage range, so that the surge current can be reduced to the minimum, and the battery is prevented from being damaged due to the influence of the surge current before being charged.

Description

Technical Field

[0001] The utility model relates to the technical field of battery charging, in particular to a control circuit for reducing charging surge current. Background Art

[0002] The output circuit of the battery charger is usually equipped with a switch circuit, the main purpose of which is to avoid sparking when the charger is connected to the battery, and to prevent damage to the charger or battery. When using a charger to charge a battery, first connect the charger to the battery, and then control the switch circuit to turn on to charge the battery. However, in this process, since there may be a voltage difference between the voltage of the charger's switch circuit before it is turned on and the battery voltage, a surge current will be generated at the moment the switch circuit is turned on. The greater the voltage difference, the greater the surge current, and the generated surge current may damage the battery or charger.

[0003] Therefore, in order to solve the above problems, the utility model provides a control circuit for reducing charging surge current which can reduce surge current. Utility Model Content

[0004] The utility model provides a control circuit for reducing charging surge current, aiming to solve the problem of large surge current of the charger.

[0005] In order to solve the above technical problems, the utility model provides a control circuit for reducing charging surge current, which includes: a power supply unit, one end of which is connected to the mains, and the other end is used to connect to the battery, the power supply unit is used to convert the mains into a direct current output voltage to charge the battery; a detection unit, one end of which is connected to the power supply unit, and the other end is used to connect to the battery, the detection unit is used to detect the output voltage and / or the battery voltage of the battery to output a corresponding detection signal; a processing unit, one end of which is connected to the power supply unit, and the other end is connected to the detection unit, the processing unit is used to output a corresponding control signal according to the detection signal; a control unit, which includes an output voltage control module, an output current control module, a feedback module and a discharge module, one end of the output voltage control module, the output current control module and the discharge module are all connected to the output voltage, and the other end is connected to the processing unit, the feedback module is connected between the output voltage control module and the output current control module, and the processing unit is used to adjust the output voltage according to the control signal so that the output voltage is the same as the battery voltage.

[0006] Further, the discharge module includes a resistor R39, a resistor R44, a resistor R35, a resistor R36 and a MOS tube Q5, one end of the resistor R39 is connected to the processing unit, and the other end is connected to one end of the resistor R44 and the gate of the MOS tube Q5, the other end of the resistor R44 is grounded, the drain of the MOS tube Q5 is connected to one end of the resistor R36, the other end of the resistor R36 is connected to one end of the resistor R35, the other end of the resistor R35 is connected to the output voltage, and the source of the MOS tube Q5 is grounded.

[0007] Furthermore, the control circuit for reducing the charging surge current also includes a voltage conversion module, one end of which is connected to the output voltage, and the other end is connected to the processing unit and the control unit, and the voltage conversion module is used to convert the output voltage into the operating voltage required by the processing unit and the control unit.

[0008] Furthermore, the output voltage control module includes a comparator U4B, a resistor R22, a resistor R27 and a resistor R28, the non-inverting input terminal of the comparator U4B is connected to one end of the resistor R27, the other end of the resistor R27 is connected to one end of the resistor R28, and the other end of the resistor R28 is connected to the output voltage; the inverting input terminal of the comparator U4B is connected to the processing unit and one end of the resistor R22, and the other end of the resistor R22 is connected to the working voltage; the output terminal of the comparator is connected to the feedback module.

[0009] Furthermore, the output current control module includes a comparator U4A, a resistor R15 and a resistor R19, the non-inverting input terminal of the comparator U4A is connected to one end of the resistor R19, and the other end of the resistor R19 is grounded; the inverting input terminal of the comparator U4A is connected to one end of the resistor R15, and the other end of the resistor R15 is connected to the working voltage; the output terminal of the comparator U4A is connected to the feedback module.

[0010] Further, the feedback module includes a resistor R18, a resistor R29, a resistor R26, a resistor R14, a diode D6, a diode D7, a TVS diode ZD2 and an optocoupler, one end of the resistor R18 is connected to the output current control module, and the other end is connected to the positive electrode of the diode D6, the negative electrode of the diode D6 is connected to the positive electrode of the TVS diode ZD2, the negative electrode of the TVS diode ZD2 is connected to one end of the resistor R14, and the other end of the resistor R14 is connected to the output voltage; one end of the resistor R26 is connected to the positive electrode of the TVS diode ZD2, and the negative electrode of the TVS diode ZD2 is connected to one end of the resistor R14. One end of the resistor R29 is connected to the output voltage control module, and the other end is connected to the anode of the diode D7, and the cathode of the diode D7 is connected to the anode of the TVS diode ZD2; one end of the resistor R29 is connected between the diode D6 and the TVS diode ZD2, and the other end is grounded; the anode of the light-emitting diode of the optocoupler is connected between the diode D7 and the TVS diode ZD2, and the cathode of the light-emitting diode of the optocoupler is grounded, one end of the photosensitive device of the optocoupler is connected to the power supply unit, and the other end of the photosensitive device of the optocoupler is grounded.

[0011] Furthermore, the detection unit includes an output voltage detection module and a battery voltage detection module, one end of the output voltage detection module is connected to the power supply unit, and the other end is connected to the processing unit; one end of the battery voltage detection module is connected to the battery, and the other end is connected to the processing unit.

[0012] Furthermore, the processing unit includes an MCU, one end of the MCU is connected to the power supply unit, the detection unit and the discharge module, and the other end of the MCU is connected to the output voltage control module.

[0013] Furthermore, the output voltage detection module includes a resistor R37, a resistor R42, a resistor R40 and a capacitor C20, one end of the resistor R37 is connected to the output voltage, the other end is connected to one end of the resistor R42, and the other end of the resistor R42 is grounded; one end of the resistor R40 is connected between the resistor R37 and the resistor R42, the other end is connected to one end of the capacitor R20 and the output voltage detection pin of the MCU, and the other end of the capacitor C20 is grounded.

[0014] Furthermore, the battery voltage detection module includes a resistor R38, a resistor R43, a resistor R41 and a capacitor C21, one end of the resistor R38 is connected to the battery, the other end is connected to one end of the resistor R43, and the other end of the resistor R43 is grounded; one end of the resistor R41 is connected between the resistor R38 and the resistor R43, the other end is connected to one end of the capacitor R21 and the battery voltage detection pin of the MCU, and the other end of the capacitor C21 is grounded.

[0015] The control circuit for reducing charging surge current disclosed by the utility model detects the output voltage and the battery voltage through the detection unit before the power supply unit charges the battery, and feeds back the detection signal to the processing unit, which outputs a corresponding control signal to the control unit according to the detection signal, and the control unit adjusts the output voltage according to the control signal so that the output voltage is the same as the battery voltage. When there is no voltage difference or a small voltage difference between the output voltage and the battery voltage, the processing unit controls the switch circuit in the power supply unit to conduct to start charging the battery. The utility model can reduce the surge current to a minimum by controlling the output voltage and the battery voltage within a small voltage range, thereby ensuring that the battery will not be damaged by the surge current before charging begins. The control circuit for reducing charging surge current disclosed by the utility model solves the problem of large surge current of the charger. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is a structural schematic diagram of a control circuit for reducing charging surge current provided by an embodiment of the utility model;

[0018] Figure 2 The utility model provides an embodiment of Figure 1 The circuit schematic diagram of the power supply unit in FIG.

[0019] Figure 3 The utility model provides an embodiment of Figure 1 The circuit schematic diagram of the control unit in;

[0020] Figure 4 This is a circuit schematic diagram of a voltage conversion module provided by an embodiment of the utility model;

[0021] Figure 5 The utility model provides an embodiment of Figure 1 The circuit schematic diagram of the detection module in FIG.

[0022] Figure 6 The utility model provides an embodiment of Figure 1 The circuit schematic diagram of the processing module in FIG.

[0023] Figure 7 This is a schematic diagram of the working process of a control circuit for reducing charging surge current provided by an embodiment of the utility model;

[0024] Reference numerals:

[0025] 10. Control circuit for reducing charging surge current; 11. Power supply unit; 111. Power supply module; 112. Switching circuit; 12. Detection unit; 121. Output voltage detection module; 122. Battery voltage detection module; 13. Processing unit; 14. Control unit; 141. Output voltage control module; 142. Output current control module; 143. Feedback module; 144. Discharge module; 15. Voltage conversion module. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0027] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0028] It should also be understood that the terms used in this utility model specification are only for the purpose of describing specific embodiments and are not intended to limit the utility model. As used in this utility model specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0029] It should be further understood that the term “and / or” used in the present specification and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0030] Figures 1 to 7An embodiment of a control circuit for reducing charging surge current provided by the utility model is demonstrated. The control circuit 10 for reducing charging surge current of this embodiment includes a power supply unit 11, a detection unit 12, a processing unit 13 and a control unit 14, wherein one end of the power supply unit 11 is connected to the AC power, and the other end is used to connect to the battery, and the power supply unit 11 is used to convert the AC power into a direct current output voltage to charge the battery; one end of the detection unit 12 is connected to the power supply unit 11, and the other end is used to connect to the battery, and the detection unit 12 is used to detect the output voltage and / or the battery voltage of the battery to output a corresponding detection signal; one end of the processing unit 13 is connected to the power supply unit 11, and the other end is connected to the detection unit 12, The processing unit 13 is used to output a corresponding control signal according to the detection signal; the control unit 14 includes an output voltage control module 141, an output current control module 142, a feedback module 143 and a discharge module 144, one end of the output voltage control module 141, the output current control module 142 and the discharge module 144 are all connected to the output voltage, and the other end is connected to the processing unit 13, the feedback module 143 is connected between the output voltage control module 141 and the output current control module 142, and the processing unit 13 is used to adjust the output voltage according to the control signal so that the output voltage is the same as the battery voltage. In this embodiment, before the power supply unit 11 charges the battery, the output voltage and the battery voltage are detected by the detection unit 12, and the detection signal is fed back to the processing unit 13, and the processing unit 13 outputs a corresponding control signal to the control unit 14 according to the detection signal, and the control unit 14 adjusts the output voltage according to the control signal so that the output voltage is the same as the battery voltage. When there is no voltage difference and / or the voltage between the output voltage and the battery voltage is small, the processing unit 13 controls the switch circuit in the power supply unit 11 to start charging the battery. The utility model can minimize the surge current by controlling the output voltage and the battery voltage within a small voltage range, thereby ensuring that the battery will not be damaged by the surge current before charging begins.

[0031] In one embodiment, such as this embodiment, Figure 2 As shown, the power supply unit 11 includes a power supply module 111 and a switch circuit 112. One end of the power supply module 111 is connected to the mains, and the other end is connected to one end of the switch circuit 112. The other end of the switch circuit 112 is used to connect to the battery. The power supply module 111 provides an output voltage Vout to the battery through the switch circuit 112. The switch circuit 112 includes an NMOS tube Q1 and an NMOS tube Q2. When the battery starts to be charged, the NMOS tube Q1 and the NMOS tube Q2 are turned on so that the output voltage Vout charges the battery.

[0032] In one embodiment, such as this embodiment, Figure 3 As shown, the discharge module 144 includes a resistor R39, a resistor R44, a resistor R35, a resistor R36 and a MOS transistor Q5, one end of the resistor R39 is connected to the processing unit 13, the other end is connected to one end of the resistor R44 and the gate of the MOS transistor Q5, the other end of the resistor R44 is grounded, the drain of the MOS transistor Q5 is connected to one end of the resistor R36, the other end of the resistor R36 is connected to one end of the resistor R35, the other end of the resistor R35 is connected to the output voltage Vout, and the source of the MOS transistor Q5 is grounded. In this embodiment, the discharge module 144 is used to discharge the output voltage to reduce the voltage value of the output voltage.

[0033] In one embodiment, such as this embodiment, Figure 4 As shown, the control circuit 10 for reducing the charging surge current also includes a voltage conversion module 15, one end of which is connected to the output voltage, and the other end is connected to the processing unit 13 and the control unit 14, and the voltage conversion module 15 is used to convert the output voltage into the working voltage required by the processing unit 13 and the control unit 14. It should be noted that in this embodiment, the working voltage converted by the voltage conversion module 15 is +5V. It can be understood that the voltage conversion module 15 can set the voltage value required for conversion according to actual needs, for example, it can be a voltage with a value of +3.0V or +3.3V.

[0034] In one embodiment, such as this embodiment, Figure 3 As shown, the output voltage control module 141 includes a comparator U4B, a resistor R22, a resistor R27 and a resistor R28, the non-inverting input terminal of the comparator U4B is connected to one end of the resistor R27, the other end of the resistor R27 is connected to one end of the resistor R28, and the other end of the resistor R28 is connected to the output voltage; the inverting input terminal of the comparator U4B is connected to the processing unit 13 and one end of the resistor R22, and the other end of the resistor R22 is connected to the working voltage; the output terminal of the comparator is connected to the feedback module 143. It can be understood that in this embodiment, the output voltage control module is used to control the voltage value of the output voltage.

[0035] In one embodiment, such as this embodiment, Figure 3As shown, the output current control module 142 includes a comparator U4A, a resistor R15 and a resistor R19, the non-inverting input terminal of the comparator U4A is connected to one end of the resistor R19, and the other end of the resistor R19 is grounded; the inverting input terminal of the comparator U4A is connected to one end of the resistor R15, and the other end of the resistor R15 is connected to the working voltage; the output terminal of the comparator U4A is connected to the feedback module 143. It can be understood that in this embodiment, the output current control module is used to control the current value of the output current of the power supply module to ensure that the output current meets the current requirement when the battery is charged.

[0036] In one embodiment, such as this embodiment, Figure 3 As shown, the feedback module 143 includes a resistor R18, a resistor R29, a resistor R26, a resistor R14, a diode D6, a diode D7, a TVS diode ZD2 and an optocoupler, one end of the resistor R18 is connected to the output current control module 142, and the other end is connected to the positive electrode of the diode D6, the negative electrode of the diode D6 is connected to the positive electrode of the TVS diode ZD2, the negative electrode of the TVS diode ZD2 is connected to one end of the resistor R14, and the other end of the resistor R14 is connected to the output voltage Vout; the resistor R26 One end is connected to the output voltage control module 141, and the other end is connected to the positive electrode of the diode D7, and the negative electrode of the diode D7 is connected to the positive electrode of the TVS diode ZD2; one end of the resistor R29 is connected between the diode D6 and the TVS diode ZD2, and the other end is grounded; the positive electrode of the light-emitting diode of the optocoupler is connected between the diode D7 and the TVS diode ZD2, and the negative electrode of the light-emitting diode of the optocoupler is grounded, one end of the photosensitive device of the optocoupler is connected to the power supply unit 11, and the other end of the photosensitive device of the optocoupler is grounded. It should be noted that in this embodiment, the optocoupler includes U1A and U1B (in Figure 2 ), wherein U1A is a light emitting diode, U1B is a photosensitive device, the output voltage control module 141 and the output current control module 142 control the conduction and cutoff of the light emitting diode of the optocoupler through the diode D6 and the diode D7 to feedback the output status to the control IC of the power supply module 111, and the control IC adjusts the working state according to the actual situation to achieve the effect of stable output.

[0037] In one embodiment, such as this embodiment, Figure 5As shown, the detection unit 12 includes an output voltage detection module 121 and a battery voltage detection module 122. One end of the output voltage detection module 121 is connected to the power supply unit 11, and the other end is connected to the processing unit 13; one end of the battery voltage detection module 122 is connected to the battery, and the other end is connected to the processing unit 13. In this embodiment, the output voltage detection module 121 is used to detect the voltage value of the output voltage Vout; the battery voltage detection module 122 is used to detect the voltage value of the battery voltage B+.

[0038] In one embodiment, such as this embodiment, Figure 6 As shown, the processing unit 13 includes an MCU, one end of the MCU is connected to the power supply unit 11, the detection unit 12 and the discharge module 144, and the other end is connected to the output voltage control module 141. Optionally, in this embodiment, the processing unit 13 also includes a filter module, such as an RC filter module, one end of the RC filter module is connected to the MCU, and the other end is connected to the output voltage control module 141, and the filter module is used to filter the PWM signal.

[0039] In one embodiment, such as this embodiment, Figure 5 As shown, the output voltage detection module 121 includes a resistor R37, a resistor R42, a resistor R40 and a capacitor C20, one end of the resistor R37 is connected to the output voltage Vout, the other end is connected to one end of the resistor R42, and the other end of the resistor R42 is grounded; one end of the resistor R40 is connected between the resistor R37 and the resistor R42, the other end is connected to one end of the capacitor R20 and the output voltage detection pin (i.e., the Out Voltage Detection pin) of the MCU, and the other end of the capacitor C20 is grounded.

[0040] In one embodiment, such as this embodiment, Figure 5 As shown, the battery voltage detection module 122 includes a resistor R38, a resistor R43, a resistor R41 and a capacitor C21, one end of the resistor R38 is connected to the battery, the other end is connected to one end of the resistor R43, and the other end of the resistor R43 is grounded; one end of the resistor R41 is connected between the resistor R38 and the resistor R43, the other end is connected to one end of the capacitor R21 and the battery voltage detection pin (i.e., the BatteryVoltage Detection pin) of the MCU, and the other end of the capacitor C21 is grounded.

[0041] For easier understanding, please refer to Figure 7The working process of reducing the charging surge current by the control circuit 10 of the utility model is described as follows:

[0042] Before the switch loop 112 in the power supply unit 11 is turned on, the output voltage Vout and the battery voltage B+ are detected by the output voltage detection module 121 and the battery voltage detection module 122 respectively, and the corresponding detection signals are fed back to the MCU. The MCU outputs a corresponding control signal according to the detection signal, such as a PWM signal. The PWM signal is filtered by a primary or secondary filter module (such as an RC filter module) to obtain a stable PWM signal, and is provided to the output voltage control module 141 as its reference voltage, and then used to adjust the output voltage Vout. Among them, when the output voltage Vout is greater than the battery voltage B+, it is necessary to first discharge through the discharge module 144 to reduce the output voltage Vout. When the output voltage Vout is reduced to be substantially the same as the battery voltage B+, the switch loop 112 in the power supply unit 11 is turned on to start charging the battery. When the output voltage Vout is less than the battery voltage B+, the output voltage control module 121 is used to boost the output voltage Vout to be substantially the same as or close to the battery voltage B+, and then the switch loop 112 in the power supply unit 11 is turned on to start charging the battery. By adjusting the output voltage Vout by increasing or decreasing the voltage, the output voltage for charging the battery can be made the same or close to the battery voltage, and the battery can be charged after ensuring that there is no large voltage difference, thereby minimizing the inrush current. It should be noted that, in this embodiment, the PWM signal output by the MCU adjusts the PWM duty cycle according to the result of the voltage detection, so as to adjust the voltage value of the output voltage Vout.

[0043] The control circuit for reducing charging surge current provided by the utility model detects the output voltage and the battery voltage through the detection unit before the power supply unit charges the battery, and feeds back the detection signal to the processing unit, which outputs a corresponding control signal to the control unit according to the detection signal, and the control unit adjusts the output voltage according to the control signal so that the output voltage is the same as the battery voltage. When there is no voltage difference or a small voltage difference between the output voltage and the battery voltage, the processing unit controls the switch circuit in the power supply unit to conduct to start charging the battery. The utility model can reduce the surge current to a minimum by controlling the output voltage and the battery voltage within a small voltage range, thereby ensuring that the battery will not be damaged by the surge current before charging begins. The control circuit for reducing charging surge current disclosed by the utility model solves the problem of large surge current of the charger.

[0044] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the utility model, and these modifications or replacements should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. A control circuit for reducing charging surge current, characterized in that: include: A power supply unit, one end of which is connected to the mains and the other end of which is used to be connected to the battery, and the power supply unit is used to convert the mains into a direct current output voltage to charge the battery; a detection unit, one end of which is connected to the power supply unit and the other end of which is used to be connected to the battery, the detection unit being used to detect the output voltage and / or the battery voltage of the battery to output a corresponding detection signal; a processing unit, one end of which is connected to the power supply unit and the other end of which is connected to the detection unit, and the processing unit is used to output a corresponding control signal according to the detection signal; A control unit, comprising an output voltage control module, an output current control module, a feedback module and a discharge module, wherein one end of the output voltage control module, the output current control module and the discharge module are all connected to the output voltage, and the other end is connected to the processing unit, the feedback module is connected between the output voltage control module and the output current control module, and the processing unit is used to adjust the output voltage according to the control signal so that the output voltage is the same as the battery voltage.

2. The control circuit for reducing charging surge current according to claim 1, characterized in that: The discharge module includes a resistor R39, a resistor R44, a resistor R35, a resistor R36 and a MOS tube Q5, one end of the resistor R39 is connected to the processing unit, and the other end is connected to one end of the resistor R44 and the gate of the MOS tube Q5, the other end of the resistor R44 is grounded, the drain of the MOS tube Q5 is connected to one end of the resistor R36, the other end of the resistor R36 is connected to one end of the resistor R35, the other end of the resistor R35 is connected to the output voltage, and the source of the MOS tube Q5 is grounded.

3. The control circuit for reducing charging surge current according to claim 1, characterized in that: The control circuit for reducing charging surge current also includes a voltage conversion module, one end of which is connected to the output voltage, and the other end is connected to the processing unit and the control unit. The voltage conversion module is used to convert the output voltage into the operating voltage required by the processing unit and the control unit.

4. The control circuit for reducing charging surge current according to claim 3, characterized in that: The output voltage control module includes a comparator U4B, a resistor R22, a resistor R27 and a resistor R28. The non-inverting input terminal of the comparator U4B is connected to one end of the resistor R27, the other end of the resistor R27 is connected to one end of the resistor R28, and the other end of the resistor R28 is connected to the output voltage; the inverting input terminal of the comparator U4B is connected to the processing unit and one end of the resistor R22, and the other end of the resistor R22 is connected to the working voltage; the output terminal of the comparator is connected to the feedback module.

5. The control circuit for reducing charging surge current according to claim 3, characterized in that: The output current control module includes a comparator U4A, a resistor R15 and a resistor R19, wherein the non-inverting input terminal of the comparator U4A is connected to one end of the resistor R19, and the other end of the resistor R19 is grounded; the inverting input terminal of the comparator U4A is connected to one end of the resistor R15, and the other end of the resistor R15 is connected to the working voltage; and the output terminal of the comparator U4A is connected to the feedback module.

6. The control circuit for reducing charging surge current according to claim 1, characterized in that: The feedback module includes a resistor R18, a resistor R29, a resistor R26, a resistor R14, a diode D6, a diode D7, a TVS diode ZD2 and an optocoupler. One end of the resistor R18 is connected to the output current control module, and the other end is connected to the positive electrode of the diode D6. The negative electrode of the diode D6 is connected to the positive electrode of the TVS diode ZD2. The negative electrode of the TVS diode ZD2 is connected to one end of the resistor R14. The other end of the resistor R14 is connected to the output voltage. One end of the resistor R26 is connected to the output current control module. The output voltage control module is connected, and the other end is connected to the anode of the diode D7, and the cathode of the diode D7 is connected to the anode of the TVS diode ZD2; one end of the resistor R29 is connected between the diode D6 and the TVS diode ZD2, and the other end is grounded; the anode of the light-emitting diode of the optocoupler is connected between the diode D7 and the TVS diode ZD2, and the cathode of the light-emitting diode of the optocoupler is grounded, one end of the photosensitive device of the optocoupler is connected to the power supply unit, and the other end of the photosensitive device of the optocoupler is grounded.

7. The control circuit for reducing charging surge current according to claim 1, characterized in that: The detection unit includes an output voltage detection module and a battery voltage detection module, one end of the output voltage detection module is connected to the power supply unit, and the other end is connected to the processing unit; one end of the battery voltage detection module is connected to the battery, and the other end is connected to the processing unit.

8. The control circuit for reducing charging surge current according to claim 1, characterized in that: The processing unit includes an MCU, one end of the MCU is connected to the power supply unit, the detection unit and the discharge module, and the other end of the MCU is connected to the output voltage control module.

9. The control circuit for reducing charging surge current according to claim 8, characterized in that: The output voltage detection module includes a resistor R37, a resistor R42, a resistor R40 and a capacitor C20, one end of the resistor R37 is connected to the output voltage, the other end is connected to one end of the resistor R42, and the other end of the resistor R42 is grounded; one end of the resistor R40 is connected between the resistor R37 and the resistor R42, the other end is connected to one end of the capacitor R20 and the output voltage detection pin of the MCU, and the other end of the capacitor C20 is grounded.

10. The control circuit for reducing charging surge current according to claim 8, characterized in that: The battery voltage detection module includes a resistor R38, a resistor R43, a resistor R41 and a capacitor C21, one end of the resistor R38 is connected to the battery, the other end is connected to one end of the resistor R43, and the other end of the resistor R43 is grounded; one end of the resistor R41 is connected between the resistor R38 and the resistor R43, the other end is connected to one end of the capacitor R21 and the battery voltage detection pin of the MCU, and the other end of the capacitor C21 is grounded.

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