Current limiting module circuit based on battery protection

Abstract

The utility model discloses a current limiting module circuit based on battery protection, which comprises a DCDC module circuit connected with a sampling end, the input end of the DCDC module circuit is also connected with a voltage reduction and stabilization power supply circuit, and the control end of the DCDC module circuit is electrically connected with a switching power supply pulse width modulation circuit; the step-down voltage-stabilizing power supply circuit supplies power to the switching power supply pulse width modulation circuit; the sampling end is connected with one end of the fuse, and the other end of the fuse leads out two paths, one path is connected with the input end of the DCDC module circuit, and the other path is electrically connected with the input end of the voltage reduction and stabilization power supply circuit. The utility model discloses a current limiting module circuit based on battery protection. Charging protection is achieved through the current limiting module, and the protection performance of the equipment is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to new energy equipment technical field especially relates to a current -limiting module circuit based on battery protection. BACKGROUND

[0002] The prior art does not consider all application scenarios, and for the application scenarios of generator application and battery parallel connection needing current limiting, adds a battery protection current -limiting module circuit in the circuit, protects the safety of the battery and the safety of external equipment, makes the external equipment work in a reasonable power range, and prolongs the service life. UTILITY MODEL CONTENTS

[0003] The utility model overcomes the insufficient of prior art, provides a current -limiting module circuit based on battery protection, realizes charging protection through current -limiting module, and improves the protection performance of equipment device.

[0004] To achieve the above object, the utility model adopts the technical scheme of a current -limiting module circuit based on battery protection, including DCDC module circuit with sampling end connection, the input of DCDC module circuit still is connected with the voltage stabilizing power supply circuit, and the control end of DCDC module circuit is electrically connected with switching power supply pulse width modulation circuit;The voltage stabilizing power supply circuit is for the power supply of switching power supply pulse width modulation circuit;And the sampling end is connected with one end of fuse, and the other end of fuse leads out two ways, one way is connected with the input of DCDC module circuit, and the other way is electrically connected with the input of voltage stabilizing power supply circuit.

[0005] In a preferred scheme of the utility model, the switching power supply pulse width modulation circuit is also connected with a temperature sensor circuit, and the temperature sensor circuit is used for detecting the peripheral environment temperature.

[0006] In a preferred scheme of the utility model, the DCDC module circuit includes MOS tube Q1, the S end of MOS tube Q1 is connected with the sampling end, the G end of MOS tube Q1 is connected with the positive phase end of diode D3 through resistance R5, the inverse phase end of diode D3 is connected with DC-ON node, the S end and the G end of MOS tube Q1 are connected through parallel resistance R2 and stabilized voltage diode ZD1, the D end of MOS tube Q1 is connected with power supply VC+, and resistance R9, capacitor CA1, capacitor CA2, series capacitor C2 and capacitor C4, parallel diode assembly D4, parallel diode assembly D5, capacitor CA3, capacitor CA4, capacitor CA5, series capacitor C3 and capacitor C5, resistance R10 are connected in parallel between the D end of MOS tube Q1 and the sampling end CHG;And the inverse phase end of capacitor C4 and diode assembly D4 is spaced through inductance L1 and is electrically connected through inductance L1;

[0007] The noninversion end of the parallel diode assembly D5 is spaced from the capacitor C3 by a MOS tube Q4, the D ends of the MOS tube Q3, the MOS tube Q2 and the MOS tube Q4 are electrically connected to the noninversion end of the parallel diode assembly D5, the S ends of the MOS tube Q3, the MOS tube Q2 and the MOS tube Q4 are electrically connected to the noninversion end of the capacitor C3, the G end of the MOS tube Q4 is connected to the PWM output end of the switching power supply pulse width modulation circuit through a resistor R12, the S end of the MOS tube Q4 is connected to the PWM output end of the switching power supply pulse width modulation circuit through a resistor R13, the G end of the MOS tube Q3 is connected to the PWM output end of the switching power supply pulse width modulation circuit through a resistor R8, and the G end of the MOS tube Q2 is connected to the PWM output end of the switching power supply pulse width modulation circuit through a resistor R4.

[0008] One end of the resistor R10 is connected to the power supply VC+, the other end of the resistor R10 is grounded GND, and the IS node is arranged between the one end of the resistor R10 and the ground GND, and the resistor RA1 and the resistor RA2 are also arranged in parallel between the IS node and the ground GND.

[0009] In a preferred scheme of the utility model, the voltage reduction and stabilization power supply circuit comprises a diode D9 connected with the sampling end, a noninversion end of the diode D9 is connected with an S end of a MOS tube Q5, a G end of the MOS tube Q5 is connected with a DC-ON node through a resistor R21, the G end and the S end of the MOS tube Q5 are connected through a parallel resistor R20 and a voltage stabilization diode ZD2, a D end of the MOS tube Q5 is connected with an input end of a voltage reduction and stabilization power supply chip U1 through a resistor R17, an enable end of the voltage reduction and stabilization power supply chip U1 is connected with the input end of the voltage reduction and stabilization power supply chip U1 through a resistor R19, a SW pin and a BST pin of the voltage reduction and stabilization power supply chip U1 are connected through a capacitor C8, a GND pin of the voltage reduction and stabilization power supply chip U1 is grounded, the SW pin and the GND pin of the voltage reduction and stabilization power supply chip U1 are connected through a diode D8, the diode D8 is connected with the input end of the voltage reduction and stabilization power supply chip U1 in parallel with a diode TVS1, a capacitor CA7, a capacitor C10 and a capacitor C11 connected in series, a connection node of the diode D8 and the capacitor C8 is output as a VCC power supply through an inductor L2 and a resistor R15 connected in series, the connection node of the inductor L2 and the resistor R15 and a node end are connected in parallel with a capacitor CA6, a capacitor C7, a resistor R16 and a resistor R18 connected in series, and the resistor R16 is also connected in parallel with a capacitor C9 at both ends; the resistor R15 and the ground end are also connected in parallel with a voltage stabilization diode TVS1, and both ends of the voltage stabilization diode TVS1 are connected in parallel with a resistor R32 and a light emitting diode LED1 connected in series.

[0010] In a preferred scheme of the utility model, the switch power supply pulse width modulation circuit includes a switch power supply pulse width modulation chip U2, one input end of the switch power supply pulse width modulation chip U2 is connected with IS node through resistance R22, and the input end is also grounded through capacitor C12, the second input end of the switch power supply pulse width modulation chip U2 is connected with the VREF pin of the switch power supply pulse width modulation chip U2 through resistance R25, the second input end is grounded through parallel capacitor C16 and resistance R26, the VREF pin of the switch power supply pulse width modulation chip U2 is connected with the ground end of capacitor C17 through capacitor C17, the VCC pin of the switch power supply pulse width modulation chip U2 is connected with the ground end of capacitor C17 through capacitor C19, the C2 pin and the VCC pin of the switch power supply pulse width modulation chip U2 are connected with power supply VCC, the E1 pin and the E2 pin of the switch power supply pulse width modulation chip U2 are connected with the PWM output end and export PWM signal, the C1 pin of the switch power supply pulse width modulation chip U2 is connected with power supply VCC, the CT pin and the RT pin of the switch power supply pulse width modulation chip U2 are grounded through capacitor C18 and resistance R29 respectively, the DCT pin of the switch power supply pulse width modulation chip U2 exports two paths, one path is grounded through resistance R28, and the other path is connected with the VREF pin through parallel resistance R27 and capacitor C20, the third input end and the FB pin of the switch power supply pulse width modulation chip U2 are connected with the connection node of resistance R27 and capacitor C20 through resistance R24, and the third input end and the FB pin are also grounded through parallel resistance R23 and capacitor C13.

[0011] In a preferred scheme of the utility model, the temperature sensor circuit includes a temperature sensor NTC, one end of the temperature sensor NTC is electrically connected with the switch power supply pulse width modulation circuit, and the other end of the temperature sensor NTC is grounded.

[0012] In a preferred scheme of the utility model, the model of the voltage reduction and stabilization power supply chip U1 is SSP9481 voltage reduction and stabilization power supply chip, and the IN+ pin of the switch power supply pulse width modulation chip U2 is connected with the VFB node connected out of capacitor C1 and resistance R1.

[0013] In a preferred scheme of the utility model, the model of the switch power supply pulse width modulation chip U2 is TL494IDR switch power supply pulse width modulation chip.

[0014] Compared with the prior art, the utility model has the beneficial effects that:

[0015] The utility model discloses a kind of current limiting module circuit based on battery protection;Charging protection is realized by current limiting module, and the protection performance of equipment device is improved.

[0016] 1. Protect the charging module of the automobile generator, reduce the load of the generator, when the current is greater than the protection current, the current limiting module is opened, so that the generator does not work under the maximum load, when the current is not to the maximum current of the generator, the maximum current is fully opened, and the generator current is detected once every certain time.

[0017] 2. When the voltage difference of the parallel battery is too large, the battery is protected. The battery with high voltage charges the battery with low voltage, and the charging current is too large to affect the service life of the battery, which is opened when the current reaches the opening protection point of the current limiting module, and is closed below a certain value. BRIEF DESCRIPTION OF DRAWINGS

[0018] The utility model is further illustrated below in combination with the drawings and embodiments.

[0019] Figure 1 The circuit of the current limiting module circuit based on battery protection is provided by an embodiment of the utility model Figure One ;

[0020] Figure 2 The circuit of the current limiting module circuit based on battery protection is provided by an embodiment of the utility model Figure Two . DETAILED DESCRIPTION

[0021] The technical scheme of the utility model is described in detail below through the drawings and specific embodiments. It should be understood that the specific features in the embodiments and the specific features in the embodiments are detailed descriptions of the technical scheme of the utility model, rather than limitations of the technical scheme of the utility model. In the case of no conflict, the technical features in the embodiments and the embodiments can be combined with each other.

[0022] The term "and / or", only describes the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which means that there are three cases of A alone, A and B together, and B alone. In addition, the character " / ", generally represents that the associated objects before and after are a "or" relationship. Embodiment one

[0023] For example Figure 1 , Figure 2As shown, a current limiting module circuit based on battery protection includes a DCDC module circuit connected to a sampling terminal. The input terminal of the DCDC module circuit is also connected to a step-down voltage-stabilizing power supply circuit. The control terminal of the DCDC module circuit is electrically connected to a switching power supply pulse-width modulation circuit; the step-down voltage-stabilizing power supply circuit supplies power to the switching power supply pulse-width modulation circuit. The sampling terminal is connected to one end of a fuse, and the other end of the fuse leads to two paths: one connected to the input terminal of the DCDC module circuit, and the other electrically connected to the input terminal of the step-down voltage-stabilizing power supply circuit. The switching power supply pulse-width modulation circuit is also connected to a temperature sensor circuit for detecting the ambient temperature. Example 2

[0024] like Figure 1 、 Figure 2 A current limiting module circuit for battery protection is shown. The circuit includes a DC-DC module circuit connected to a sampling terminal. The input terminal of the DC-DC module circuit is also connected to a step-down regulated power supply circuit. The control terminal of the DC-DC module circuit is electrically connected to a switching power supply pulse-width modulation circuit. The step-down regulated power supply circuit supplies power to the switching power supply pulse-width modulation circuit. The sampling terminal is connected to one end of a fuse. The other end of the fuse leads to two leads: one connected to the input terminal of the DC-DC module circuit, and the other connected to the input terminal of the step-down regulated power supply circuit. The switching power supply pulse-width modulation circuit is also connected to a temperature sensor circuit for detecting the ambient temperature. The temperature sensor circuit includes an NTC temperature sensor. One end of the NTC temperature sensor is electrically connected to the switching power supply pulse-width modulation circuit, and the other end is grounded. Specifically, the NTC is used to measure the temperature of the DC-DC mainboard MOS transistor. The TH1 pin of the temperature sensor is the measurement point for the NTC. The B+ node is the battery's positive terminal, and CHG is the terminal that controls the charging function. When the current needs to be measured, the current is measured through the current-sense resistor (i.e. resistor RA2).

[0025] Specifically, the DCDC module circuit includes a MOS tube Q1, the S end of the MOS tube Q1 is connected with the sampling end, the G end of the MOS tube Q1 is connected with the positive end of a diode D3 through a resistor R5, and the inverse end of the diode D3 is connected with a DC-ON node. Specifically, the inverse end of the diode D3 is connected to a control mainboard to determine whether to enable the DCDC current limiting module. The S end and the G end of the MOS tube Q1 are connected through a parallel resistor R2 and a stabilizing diode ZD1, the D end of the MOS tube Q1 is connected with a power supply VC+, and the D end of the MOS tube Q1 and the sampling end CHG are connected in parallel with a resistor R9, a capacitor CA1, a capacitor CA2, a capacitor C2 and a capacitor C4 connected in series, a diode assembly D4 connected in parallel, a diode assembly D5 connected in parallel, a capacitor CA3, a capacitor CA4, a capacitor CA5, a capacitor C3 and a capacitor C5 connected in series, and a resistor R10; and the capacitor C4 and the inverse end of the diode assembly D4 are separated through an inductor L1 and are electrically connected through the inductor L1; the inverse end of the diode assembly D5 connected in parallel is separated from the capacitor C3 through a MOS tube Q4, the D ends of the MOS tubes Q3, Q2 and Q4 are connected with the inverse end of the diode assembly D5 connected in parallel, the S ends of the MOS tubes Q3, Q2 and Q4 are connected with the inverse end of the capacitor C3, the G end of the MOS tube Q4 is connected with the PWM output end of a switching power supply pulse width modulation circuit through a resistor R12, and the S end of the MOS tube Q4 is connected with the PWM output end of the switching power supply pulse width modulation circuit through a resistor R13; and the G end of the MOS tube Q3 is connected with the PWM output end of the switching power supply pulse width modulation circuit through a resistor R8; the G end of the MOS tube Q2 is connected with the PWM output end of the switching power supply pulse width modulation circuit through a resistor R4; one end of the resistor R10 is connected with the power supply VC+, the other end of the resistor R10 is grounded GND, and the one end of the resistor R10 grounded and the ground GND are provided with an IS node, and the IS node and the ground GND are further provided with a resistor RA1 and a resistor RA2 connected in parallel.

[0026] Specifically, the voltage reduction and stabilization power supply circuit comprises a voltage reduction and stabilization power supply chip U1, the model of the voltage reduction and stabilization power supply chip U1 is SSP9481 voltage reduction and stabilization power supply chip; and a diode D9 connected with the sampling end, the inverse phase end of the diode D9 is connected with the S end of a MOS tube Q5, the G end of the MOS tube Q5 is connected with a DC-ON node through a resistor R21, and the G end and the S end of the MOS tube Q5 are connected through a parallel resistor R20 and a voltage stabilization diode ZD2, the D end of the MOS tube Q5 is connected with the input end of the voltage reduction and stabilization power supply chip U1 through a resistor R17, the enable end of the voltage reduction and stabilization power supply chip U1 is connected with the input end of the voltage reduction and stabilization power supply chip U1 through a resistor R19, the SW pin and the BST pin of the voltage reduction and stabilization power supply chip U1 are connected through a capacitor C8, the GND pin of the voltage reduction and stabilization power supply chip U1 is grounded, the SW pin and the GND pin of the voltage reduction and stabilization power supply chip U1 are connected through a diode D8, the ground end of the diode D8 and the input end of the voltage reduction and stabilization power supply chip U1 are connected in parallel with a diode TVS1, a capacitor CA7, a capacitor C10 and a capacitor C11 connected in series, the connection node of the diode D8 and the capacitor C8 is output as a VCC power supply through a series inductor L2 and a resistor R15, the connection node and the node end of the inductor L2 and the resistor R15 are connected in parallel with a capacitor CA6, a capacitor C7, a resistor R16 and a resistor R18 connected in series, and the resistor R16 is also connected in parallel with a capacitor C9 at both ends; the resistor R15 and the ground end are also connected in parallel with a voltage stabilization diode TVS1, and the voltage stabilization diode TVS1 is connected in parallel with a resistor R32 and a light emitting diode LED1 connected in series at both ends.

[0027] Specifically, the switching power supply pulse width modulation circuit includes a switching power supply pulse width modulation chip U2, and the model used by the switching power supply pulse width modulation chip U2 is a TL494IDR switching power supply pulse width modulation chip. The input terminal 1 of the switching power supply pulse width modulation chip U2 is connected to the IS node through the resistor R22, and the input terminal 1 is also grounded through the capacitor C12. The input terminal 2 of the switching power supply pulse width modulation chip U2 is connected to the VREF pin of the switching power supply pulse width modulation chip U2 through the resistor R25, and the input terminal 2 is grounded through the parallel capacitor C16 and the resistor R26. The VREF pin of the switching power supply pulse width modulation chip U2 is connected to the GND ground terminal through the capacitor C17; the VCC pin of the switching power supply pulse width modulation chip U2 is connected to the ground terminal of the capacitor C17 through the capacitor C19; the C2 pin and the VCC pin of the switching power supply pulse width modulation chip U2 are connected to the power supply VCC; the switching power supply pulse width modulation chip U2 The E1 and E2 pins of the switching power supply pulse width modulation chip U2 are connected at the same point as the PWM output terminal to output the PWM signal. The C1 pin of the switching power supply pulse width modulation chip U2 is connected to the power supply VCC. The CT and RT pins of the switching power supply pulse width modulation chip U2 are grounded through capacitor C18 and resistor R29, respectively. The DCT pin of the switching power supply pulse width modulation chip U2 is connected to two paths, one of which is grounded through resistor R28, and the other is connected to the VREF pin through a parallel resistor R27 and capacitor C20. The three input pins and the FB pin of the switching power supply pulse width modulation chip U2 are connected at the same point to the connection node of resistor R27 and capacitor C20 through resistor R24. The three input pins and the FB pin are also connected at the same point to ground through a parallel resistor R23 and capacitor C13. The 1IN+ pin of the switching power supply pulse width modulation chip U2 is connected to the VFB node formed by the connection of capacitor C1 and resistor R1.

[0028] Working principle:

[0029] This utility model discloses a current-limiting module circuit for battery protection. This module implements charging protection and improves the protection performance of equipment. The module detects the external charging current. When the charging current reaches the module's protection point, the module activates and limits the charging current, protecting the battery from damage caused by high current charging. It also protects the external generator from operating at maximum load.

[0030] This protects charging modules, such as vehicle alternators, by reducing the alternator's load. When the current exceeds the protection current, the current limiter activates, preventing the alternator from operating at maximum load. When the current falls below the alternator's maximum current, the current limiter is fully activated, monitoring the alternator's current at regular intervals. This protects batteries when the voltage differential between parallel connected batteries is excessive. When a high-voltage battery charges a lower-voltage battery, excessive charging current can affect battery life. The current limiter activates when the current reaches the protection point and shuts down when the current falls below a certain value.

[0031] According to the ideal embodiment of the present application, through the above description, relevant personnel can make various changes and modifications without deviating from the technical idea of the present application. The technical scope of the present application is not limited to the content of the specification, and the technical scope must be determined according to the scope of claims.

Claims

1. A battery protection based current limiting module circuit, characterized by: The DCDC module circuit connected with the sampling end, the input end of the DCDC module circuit is also connected with a voltage reduction and voltage stabilization power supply circuit, and the control end of the DCDC module circuit is electrically connected with a switching power supply pulse width modulation circuit; the voltage reduction and voltage stabilization power supply circuit supplies power for the switching power supply pulse width modulation circuit; And the sampling end is connected with one end of a fuse, and the other end of the fuse leads out two paths, one of which is connected with the input end of the DCDC module circuit, and the other of which is electrically connected with the input end of the voltage reduction and voltage stabilization power supply circuit.

2. The battery protection based current limited module circuit of claim 1, wherein: The switching power supply pulse width modulation circuit is also connected with a temperature sensor circuit, which is used for detecting the peripheral environment temperature.

3. The battery protection based current limited module circuit of claim 2, wherein: The DCDC module circuit comprises a MOS tube Q1, the S end of the MOS tube Q1 is connected with the sampling end, the G end of the MOS tube Q1 is connected with the positive phase end of a diode D3 through a resistor R5, the inverse phase end of the diode D3 is connected with a DC-ON node, the S end and the G end of the MOS tube Q1 are connected through a parallel resistor R2 and a voltage stabilization diode ZD1, the D end of the MOS tube Q1 is connected with a power supply VC+, and the D end of the MOS tube Q1 and the sampling end CHG are connected in parallel with a resistor R9, a capacitor CA1, a capacitor CA2, a capacitor C2 and a capacitor C4 connected in series, a diode assembly D4 connected in parallel, a diode assembly D5 connected in parallel, a capacitor CA3, a capacitor CA4, a capacitor CA5, a capacitor C3 and a capacitor C5 connected in series, and a resistor R10; and the capacitor C4 and the inverse phase end of the diode assembly D4 are separated by an inductor L1 and are electrically connected through the inductor L1; The inverse phase end of the diode assembly D5 connected in parallel is separated from the capacitor C3 through a MOS tube Q4, the D ends of the MOS tubes Q3, Q2 and Q4 are connected with the inverse phase end of the diode assembly D5 connected in parallel, the S ends of the MOS tubes Q3, Q2 and Q4 are connected with the inverse phase end of the capacitor C3, the G end of the MOS tube Q4 is connected with the PWM output end of the switching power supply pulse width modulation circuit through a resistor R12, the S end of the MOS tube Q4 is connected with the PWM output end of the switching power supply pulse width modulation circuit through a resistor R13, the G end of the MOS tube Q3 is connected with the PWM output end of the switching power supply pulse width modulation circuit through a resistor R8, and the G end of the MOS tube Q2 is connected with the PWM output end of the switching power supply pulse width modulation circuit through a resistor R4; One end of the resistor R10 is connected with the power supply VC+, the other end of the resistor R10 is grounded GND, and the IS node is arranged between the one end of the resistor R10 connected with the power supply VC+ and the ground GND, and a resistor RA1 and a resistor RA2 are also arranged in parallel between the IS node and the ground GND.

4. The battery protection based current limited module circuit of claim 3, wherein: The voltage reduction and stabilization power supply circuit comprises a diode D9 connected with the sampling end, an opposite end of the diode D9 is connected with an S end of a MOS tube Q5, a G end of the MOS tube Q5 is connected with a DC-ON node through a resistor R21, the G end and the S end of the MOS tube Q5 are connected through a parallel resistor R20 and a voltage stabilization diode ZD2, a D end of the MOS tube Q5 is connected with an input end of a voltage reduction and stabilization power supply chip U1 through a resistor R17, an enable end of the voltage reduction and stabilization power supply chip U1 is connected with the input end of the voltage reduction and stabilization power supply chip U1 through a resistor R19, a SW pin and a BST pin of the voltage reduction and stabilization power supply chip U1 are connected through a capacitor C8, a GND pin of the voltage reduction and stabilization power supply chip U1 is grounded, the SW pin and the GND pin of the voltage reduction and stabilization power supply chip U1 are connected through a diode D8, the diode D8 is connected in parallel with a diode TVS1, a capacitor CA7, a capacitor C10 and a capacitor C11 between the ground end and the input end of the voltage reduction and stabilization power supply chip U1, a connection node of the diode D8 and the capacitor C8 is output as a VCC power supply through a serial inductor L2 and a resistor R15, the connection node and a node end of the inductor L2 and the resistor R15 are connected in parallel with a capacitor CA6, a capacitor C7, a serial resistor R16 and a resistor R18, and the resistor R16 is also connected in parallel with a capacitor C9 between two ends; the resistor R15 and the ground end are also connected in parallel with a voltage stabilization diode TVS1, the voltage stabilization diode TVS1 is connected in parallel with a serial resistor R32 and a light emitting diode LED1 between two ends.

5. The battery protection based current limited module circuit of claim 4, wherein: The switching power supply pulse width modulation circuit comprises a switching power supply pulse width modulation chip U2, an input end one of the switching power supply pulse width modulation chip U2 is connected with an IS node through a resistor R22, and the input end one is also grounded through a capacitor C12, an input end two of the switching power supply pulse width modulation chip U2 is connected with a VREF pin of the switching power supply pulse width modulation chip U2 through a resistor R25, the input end two is grounded through a capacitor C16 and a resistor R26 in parallel, the VREF pin of the switching power supply pulse width modulation chip U2 is connected with a GND ground end through a capacitor C17; a VCC pin of the switching power supply pulse width modulation chip U2 is connected with a ground end of the capacitor C17 through a capacitor C19; a C2 pin and the VCC pin of the switching power supply pulse width modulation chip U2 are connected with a power supply VCC at a common point; an E1 pin and an E2 of the switching power supply pulse width modulation chip U2 are connected at a common point and then lead out a PWM signal as a PWM output end; a C1 pin of the switching power supply pulse width modulation chip U2 is connected with the power supply VCC; a CT pin and an RT pin of the switching power supply pulse width modulation chip U2 are respectively grounded through a capacitor C18 and a resistor R29; a DCT pin of the switching power supply pulse width modulation chip U2 leads out two paths, one path is grounded through a resistor R28, and the other path is connected with the VREF pin through a resistor R27 and a capacitor C20 in parallel; an input end three pin and an FB pin of the switching power supply pulse width modulation chip U2 are connected at a common point, connected with a connection node of the resistor R27 and the capacitor C20 through a resistor R24, and the input end three pin and the FB pin are also grounded through a resistor R23 and a capacitor C13 arranged in parallel.

6. The battery protection based current limited module circuit of claim 5, wherein: The temperature sensor circuit comprises a temperature sensor NTC, one end of the temperature sensor NTC is electrically connected with the switching power supply pulse width modulation circuit, and the other end of the temperature sensor NTC is grounded.

7. The battery protection based current limited module circuit of claim 6, wherein: The model of the step-down voltage stabilizing power supply chip U1 is SSP9481 step-down voltage stabilizing power supply chip.

8. The battery protection based current limited module circuit of claim 7, wherein: The model of the switching power supply pulse width modulation chip U2 is TL494IDR switching power supply pulse width modulation chip, and a 1IN+ pin of the switching power supply pulse width modulation chip U2 is connected with a VFB node connected out of the capacitor C1 and the resistor R1.

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