A battery short circuit protection circuit

Abstract

The application relates to a battery short circuit protection circuit, which comprises a voltage acquisition circuit, a short circuit judgment circuit, a main loop on-off control circuit and a lock delay circuit, wherein the main loop voltage of the main loop to be protected is acquired through the voltage acquisition circuit, short circuit detection is carried out through the short circuit judgment circuit, a short circuit judgment signal is output, then the on-off of the main loop to be protected is controlled according to the short circuit judgment signal through the main loop on-off control circuit, meanwhile, the output state of the short circuit judgment signal is maintained through the lock delay circuit to maintain the main loop to be protected in the off state, so that the short circuit problem can be repaired, the output state of the short circuit judgment signal is released by the lock delay circuit after a preset time, the protection main loop is recovered, the self-recovery of the main loop is realized, and the continuous triggering and recovery of the short circuit judgment signal can be responded more quickly under the condition of frequent short circuit.

Description

Technical Field

[0001] This invention relates to the field of battery protection technology, and in particular to a battery short-circuit protection circuit. Background Technology

[0002] For fields such as vehicle batteries, home energy storage, residential energy storage, and industrial and commercial energy storage, with the development of technology and the demand for electricity, the demand for clean energy is increasing day by day due to the excellent characteristics of lithium-ion batteries, such as high energy density, small size, long cycle life, and low self-discharge rate. As a result, the requirements for system safety are also increasing day by day, and the protection performance of circuits is also receiving much attention.

[0003] The Battery Management System (BMS) places extremely high demands on the stability and safety of its internal protection circuits. The configuration and mechanism of short-circuit protection, in particular, determine the overall system's functional safety and personal safety in the event of a short-circuit overcurrent. In practical circuit protection design, the effectiveness of short-circuit protection significantly protects the system from overcurrent surges caused by internal or external factors during operation.

[0004] However, current battery management systems typically employ the following short-circuit protection circuit designs: 1. No short-circuit protection circuit is designed; short-circuit protection relies solely on fuses. This approach suffers from the inability to self-restore after the fuse blows during a normal short circuit, resulting in a poor user experience. 2. A short-circuit protection circuit is designed, but upon short-circuit, the main circuit switch disconnects, requiring manual intervention or operation, which is difficult to implement in unattended areas. Therefore, there is an urgent need for a battery short-circuit protection circuit capable of automatically restoring normal power supply. Summary of the Invention

[0005] In view of this, it is necessary to provide a battery short-circuit protection circuit to solve the problem that the existing technology cannot recover on its own after performing short-circuit protection action.

[0006] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution: This invention provides a battery short-circuit protection circuit, including a voltage acquisition circuit, a short-circuit detection circuit, a main circuit on / off control circuit, and a locking delay circuit. The voltage acquisition circuit is electrically connected to the main circuit to be protected and the short-circuit detection circuit. The short-circuit detection circuit is electrically connected to the main circuit on / off control circuit and the locking delay circuit. The main circuit on / off control circuit is electrically connected to the main circuit to be protected. The voltage acquisition circuit is used to acquire the main circuit voltage of the main circuit to be protected; The short-circuit detection circuit is used to output a short-circuit detection signal based on the main circuit voltage; The main circuit on / off control circuit is used to control the on / off state of the main circuit to be protected according to the short circuit determination signal. The locking delay circuit is used to maintain and release the output state of the short-circuit determination signal after a preset time.

[0007] Furthermore, the voltage acquisition circuit includes an amplifier P1, the positive and negative input terminals of which are electrically connected to the main circuit to be protected, and the output terminal of the amplifier P1 is electrically connected to the short-circuit detection circuit.

[0008] Furthermore, the short-circuit detection circuit includes a comparator P2 and a reference detection voltage input circuit. The positive and negative input terminals of the comparator P2 are electrically connected to the output terminal of the amplifier P1 and the reference detection voltage input circuit, respectively. The output terminal of the comparator P2 is electrically connected to the main circuit on / off control circuit and the lockout delay circuit. The output terminal of the comparator P2 is used to output the short-circuit detection signal.

[0009] Furthermore, the locking delay circuit includes a locking circuit and a delay circuit. The locking circuit is electrically connected to the output terminal of the comparator P2 and is used to maintain the output state of the short circuit determination signal. The delay circuit is electrically connected to the locking circuit and is used to release the output state of the short circuit determination signal after a preset time.

[0010] Furthermore, the locking circuit includes a diode D1 and a resistor R8. The positive terminal of the diode D1 is electrically connected to the output terminal of the comparator P2, the negative terminal of the diode D1 is electrically connected to one end of the resistor R8, and the other end of the resistor R8 is electrically connected to the positive input terminal of the comparator P2.

[0011] Furthermore, the lockout delay circuit also includes a diode D2 and an NMOS transistor Q4. The delay circuit includes a diode D3, a resistor R13, a resistor R14, and a capacitor C2. The anode of the diode D2 is electrically connected to the output terminal of the comparator P2. The cathode of the diode D2 is electrically connected to the cathode of the diode D3 and one end of the resistor R14. One end of the resistor R13 is electrically connected to the anode of the diode D3 and the other end of the resistor R14. The other end of the resistor R13 is grounded. One end of the capacitor C2 is electrically connected to the other end of the resistor R14 and the gate of the NMOS transistor Q4. The other end of the capacitor C2 is grounded. The source of the NMOS transistor Q4 is grounded. The drain of the NMOS transistor Q4 is electrically connected to the positive input terminal of the comparator P2.

[0012] Furthermore, the lockout delay circuit also includes an absorption circuit, which includes a transistor Q5 and a resistor R12. The transistor Q5 is a PNP transistor. The base of the transistor Q5 is electrically connected to the output terminal of the comparator P2. The emitter of the transistor Q5 is electrically connected to one end of the resistor R14. The collector of the transistor Q5 is electrically connected to one end of the resistor R12. The other end of the resistor R12 is grounded.

[0013] Furthermore, the main circuit on / off control circuit includes: transistor Q3, resistor R9, transistor Q1, resistor R11, transistor Q2, and resistor R10. Transistor Q3 is an NPN transistor. The base of transistor Q3 is electrically connected to the output terminal of comparator P2, and the emitter of transistor Q3 is grounded. One end of resistor R9 is electrically connected to the power supply input, and the other end of resistor R9 is electrically connected to the collector of transistor Q3 and the base of transistor Q1. Q1 is an NPN transistor with its emitter grounded. The collector of Q1 is electrically connected to one end of resistor R11, and the other end of resistor R11 is electrically connected to the base of transistor Q2. Transistor Q2 is a PNP transistor with its collector electrically connected to the on / off control drive terminal in the main circuit to be protected. The emitter of Q2 is electrically connected to one end of resistor R10, and the other end of resistor R10 is electrically connected to the power supply input.

[0014] Furthermore, the voltage acquisition circuit also includes a high-precision shunt, which is connected in series in the main circuit to be protected, and the positive and negative input terminals of the amplifier P1 are electrically connected to the two ends of the high-precision shunt, respectively.

[0015] Furthermore, the reference voltage input circuit includes a diode D4, a resistor R7, and a resistor R5. One end of the diode D4 is electrically connected to the power supply input, the other end of the diode D4 is electrically connected to one end of the resistor R7, the other end of the resistor R7 is electrically connected to one end of the resistor R5, the other end of the resistor R5 is grounded, and one end of the resistor R5 is electrically connected to the negative input terminal of the comparator P2.

[0016] This invention provides a battery short-circuit protection circuit, comprising a voltage acquisition circuit, a short-circuit judgment circuit, a main circuit on / off control circuit, and a locking delay circuit. The voltage acquisition circuit acquires the main circuit voltage of the main circuit to be protected, and the short-circuit judgment circuit performs short-circuit detection and outputs a short-circuit judgment signal. Then, the main circuit on / off control circuit controls the on / off state of the main circuit to be protected based on the short-circuit judgment signal. Simultaneously, the locking delay circuit maintains the output state of the short-circuit judgment signal to keep the main circuit to be protected in an off state, thereby enabling short-circuit repair. After a preset time, the locking delay circuit releases the output state of the short-circuit judgment signal, allowing the main circuit to recover, achieving self-recovery of the main circuit. Attached Figure Description

[0017] Figure 1 A schematic diagram of an embodiment of the battery short-circuit protection circuit provided by the present invention; Figure 2 A circuit structure diagram of an embodiment of the voltage acquisition circuit, short circuit detection circuit and locking delay circuit provided by the present invention; Figure 3 A circuit structure diagram of an embodiment of the main circuit on / off control circuit provided by the present invention; Figure 4 A circuit structure diagram of an embodiment of the locking delay circuit provided by the present invention; Figure 5 The signal timing diagram of the battery short-circuit protection circuit provided by the present invention. Detailed Implementation

[0018] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0019] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0020] This invention uses a locking delay circuit to maintain the short-circuit determination signal used to control the on / off state of the main circuit in the output state and disconnect it after a certain time, so as to realize the self-recovery of the main circuit to be protected after the short-circuit protection action.

[0021] Combination Figure 1As shown, the present invention provides a battery short-circuit protection circuit 100, characterized in that it includes a voltage acquisition circuit 110, a short-circuit judgment circuit 120, a main circuit on / off control circuit 130, and a locking delay circuit 140. The voltage acquisition circuit 110 is electrically connected to the main circuit to be protected and the short-circuit judgment circuit 120. The short-circuit judgment circuit 120 is electrically connected to the main circuit on / off control circuit 130 and the locking delay circuit 140. The main circuit on / off control circuit 130 is electrically connected to the main circuit to be protected, wherein: The voltage acquisition circuit 110 is used to acquire the main circuit voltage of the main circuit to be protected; The short-circuit detection circuit 120 is used to output a short-circuit detection signal based on the main circuit voltage. The main circuit on / off control circuit 130 is used to control the on / off state of the main circuit to be protected according to the short circuit determination signal. The locking delay circuit 140 is used to maintain and release the output state of the short circuit determination signal after a preset time.

[0022] This invention provides a battery short-circuit protection circuit 100, which includes a voltage acquisition circuit 110, a short-circuit judgment circuit 120, a main circuit on / off control circuit 130, and a locking delay circuit 140. The voltage acquisition circuit 110 acquires the main circuit voltage of the main circuit to be protected, and the short-circuit judgment circuit 120 performs short-circuit detection and outputs a short-circuit judgment signal. Then, the main circuit on / off control circuit 130 controls the on / off state of the main circuit to be protected according to the short-circuit judgment signal. Simultaneously, the locking delay circuit 140 maintains the output state of the short-circuit judgment signal to keep the main circuit to be protected in an off state, thereby enabling short-circuit repair. After a preset time, the locking delay circuit 140 releases the output state of the short-circuit judgment signal, allowing the main circuit to recover, thus achieving self-recovery of the main circuit.

[0023] Combination Figure 2 As shown, in a preferred embodiment, the voltage acquisition circuit 110 in this embodiment includes an amplifier P1, the positive input terminal and the negative input terminal of the amplifier P1 are both electrically connected to the main circuit to be protected, and the output terminal of the amplifier P1 is electrically connected to the short circuit judgment circuit 120.

[0024] Furthermore, as a preferred embodiment, the voltage acquisition circuit 110 in this embodiment also includes a high-precision shunt, which is connected in series in the main circuit to be protected, and the positive input terminal and negative input terminal of the amplifier P1 are electrically connected to the two ends of the high-precision shunt, respectively.

[0025] Combination Figure 3As shown, the main circuit to be protected in this embodiment (hereinafter referred to as the main circuit) includes a battery terminal and a main circuit MOS drive terminal. The main circuit MOS drive terminal is used to drive the MOS in the main circuit to control the on / off state of the main circuit. It is understood that, for ease of explanation, the appendix... Figures 2-3 The voltages at different locations in the circuit are labeled V1 to V9. These are for illustrative purposes only and do not represent any specific components. The main circuit to be protected typically has multiple high-precision shunts. In this embodiment, the high-precision shunt is positioned between the battery terminal and the main circuit MOS drive terminal. Its voltage is typically a few milliohms. Dividing the difference between V1 and V2 by this few milliohms yields the current value in the main circuit. By judging this current value, it can be determined whether a short circuit has occurred.

[0026] In a more specific embodiment, amplifier P1 in the voltage acquisition circuit is a high-precision operational amplifier. The voltage acquisition circuit also includes resistors R1, R2, R3, capacitor C1, and resistor R4. One end of resistor R1 is grounded, and the other end is electrically connected to the positive input terminal of amplifier P1. One end of resistor R2 is connected to the main circuit to be protected (i.e., the location of V1), and the other end is electrically connected to the positive input terminal of amplifier P1. One end of resistor R3 is connected to the main circuit to be protected (i.e., the location of V2), and the other end is electrically connected to the negative input terminal of amplifier P1. The two ends of capacitor C1 are connected to the positive and negative input terminals of amplifier P1, respectively. The two ends of resistor R4 are also connected to the positive and negative input terminals of amplifier P1, respectively.

[0027] V1 and V2 are the voltage detection terminals on both sides of the high-precision shunt in the main circuit, used to measure the current value of the main circuit, i.e., the main circuit voltage. Operational amplifier P1, acting as a differential amplifier, amplifies the difference between V1 and V2 according to the design value to obtain the output voltage V7 of amplifier P1. ) )

[0028] Furthermore, in combination Figure 2 As shown in the preferred embodiment, the short-circuit judgment circuit 120 in this embodiment includes a comparator P2 and a reference judgment voltage input circuit. The positive and negative input terminals of the comparator P2 are electrically connected to the output terminal of the amplifier P1 and the reference judgment voltage input circuit, respectively. The output terminal of the comparator P2 is electrically connected to the main circuit on / off control circuit 130 and the lockout delay circuit 140. The output terminal of the comparator P2 is used to output the short-circuit judgment signal.

[0029] In one specific embodiment, the short-circuit detection circuit 120 further includes a resistor R6, the two ends of which are electrically connected to the output terminal of the amplifier P1 and the positive input terminal of the comparator P2, respectively.

[0030] Furthermore, as a preferred embodiment, the reference voltage input circuit in this embodiment includes a diode D4, a resistor R7, and a resistor R5. One end of the diode D4 is electrically connected to the power supply input, and its voltage is V3. The other end of the diode D4 is electrically connected to one end of the resistor R7. The other end of the resistor R7 is electrically connected to one end of the resistor R5. The other end of the resistor R5 is grounded. One end of the resistor R5 is electrically connected to the negative input terminal of the comparator P2.

[0031] The circuit described above outputs the comparison voltage V8 calculated by the system after V3 is matched with R7 and R5. Then, it compares the voltage with the voltage V8 by comparator P2. When V7 > V8, the output V4 of comparator P2 is high, which is the short circuit determination signal.

[0032] Combination Figure 3 As shown in the preferred embodiment, the main circuit on / off control circuit 130 in this embodiment includes: transistor Q3, resistor R9, transistor Q1, resistor R11, transistor Q2, and resistor R10. Transistor Q3 is an NPN transistor. The base of transistor Q3 is electrically connected to the output terminal of comparator P2, and the emitter of transistor Q3 is grounded. One end of resistor R9 is electrically connected to the power supply input V5, and the other end of resistor R9 is electrically connected to the collector of transistor Q3 and the base of transistor Q1. The transistor Q1 is an NPN transistor with its emitter grounded. The collector of transistor Q1 is electrically connected to one end of resistor R11, and the other end of resistor R11 is electrically connected to the base of transistor Q2, which is a PNP transistor. The collector of transistor Q2 is electrically connected to the on / off control drive terminal in the main circuit to be protected, and the emitter of transistor Q2 is electrically connected to one end of resistor R10. The other end of resistor R10 is electrically connected to the power supply input V6.

[0033] When the short-circuit detection circuit 120 outputs a short-circuit detection signal, the high level of V4 drives transistor Q3, pulling the drive V5 of transistor Q1 to ground, thereby causing Q2 to disconnect and disconnecting the drive terminal of the main circuit MOS, thus disconnecting the main circuit to be protected and achieving short-circuit protection. It can be understood that in this embodiment, the drive terminal of the main circuit MOS in the circuit to be protected is the on / off control drive terminal. In practice, depending on the specific arrangement of the main circuit, the on / off control drive terminal can also be other ports, such as the low-voltage control terminal of a relay, or the I / O pin of a chip.

[0034] Furthermore, in combination Figure 2and Figure 4 As shown, in a preferred embodiment, the locking delay circuit 140 in this embodiment includes a locking circuit and a delay circuit. The locking circuit is electrically connected to the output terminal of the comparator P2 and is used to maintain the output state of the short circuit determination signal. The delay circuit is electrically connected to the locking circuit and is used to release the output state of the short circuit determination signal after a preset time.

[0035] Specifically, as a preferred embodiment, the locking circuit in this embodiment includes a diode D1 and a resistor R8. The positive terminal of the diode D1 is electrically connected to the output terminal of the comparator P2, the negative terminal of the diode D1 is electrically connected to one end of the resistor R8, and the other end of the resistor R8 is electrically connected to the positive input terminal of the comparator P2.

[0036] When amplifier P1 outputs a high level V4, a signal is formed through diode D1 and resistor R8, which is the voltage at position V9, ensuring that V4 is maintained continuously.

[0037] Furthermore, as a preferred embodiment, the lock-in delay circuit 140 in this embodiment further includes a diode D2 and an NMOS transistor Q4. The delay circuit includes a diode D3, a resistor R13, a resistor R14, and a capacitor C2. The anode of the diode D2 is electrically connected to the output terminal of the comparator P2. The cathode of the diode D2 is electrically connected to the cathode of the diode D3 and one end of the resistor R14. One end of the resistor R13 is electrically connected to the anode of the diode D3 and the other end of the resistor R14. The other end of the resistor R13 is grounded. One end of the capacitor C2 is electrically connected to the other end of the resistor R14 and the gate of the NMOS transistor Q4. The other end of the capacitor C2 is grounded. The source of the NMOS transistor Q4 is grounded. The drain of the NMOS transistor Q4 is electrically connected to the positive input terminal of the comparator P2.

[0038] Voltage V4 is output to the delay circuit through diode D2. After 3 seconds (the preset time is the design time value of the delay RC circuit in this embodiment, which can be changed according to specific circumstances), it drives NMOS transistor Q4 to conduct, thereby pulling the level of V9 low, thus releasing the latch. When the level of V4 goes low, the short-circuit protection disappears, and the MOS transistor in the main circuit returns to closed, thus releasing the short-circuit protection state and achieving self-recovery. If the main circuit current still reaches the short-circuit protection threshold, the short-circuit protection will continue to be triggered.

[0039] Furthermore, as a preferred embodiment, the lockout delay circuit 140 in this embodiment also includes an absorption circuit, which includes a transistor Q5 and a resistor R12. The transistor Q5 is a PNP transistor. The base of the transistor Q5 is electrically connected to the output terminal of the comparator P2. The emitter of the transistor Q5 is electrically connected to one end of the resistor R14. The collector of the transistor Q5 is electrically connected to one end of the resistor R12. The other end of the resistor R12 is grounded.

[0040] The absorption circuit is used to absorb the RC charging energy of the delay circuit, which facilitates continuous short circuit detection and the effectiveness of the delay circuit during execution.

[0041] The signal timing diagram in this embodiment is as follows: Figure 5 As shown: 1. When V7 > V8, after time t1, the short-circuit drive signal V4 is output; 2. After time t2, the delay circuit voltage of V4 reaches the driving threshold of Q4. At this time, Q4 is pulled to ground. After time t3, the driving signal of V4 is pulled to ground. 3. After the V4 drive signal is pulled to ground, the energy of the delay circuit is released through the absorption circuit. At this time, the main circuit is closed. If the short circuit continues and reaches the short circuit current threshold, the short circuit protection will be triggered again.

[0042] Specifically, this invention employs a high-precision operational amplifier and designs an absorption circuit and a delay circuit. It utilizes circuit latching to ensure the effectiveness of the short circuit, and uses a delay to disengage the latch, achieving the requirement of self-recovery after a short circuit. The circuit design in this embodiment has the following advantages: 1. A short-circuit protection circuit composed of a differential amplifier and a comparator can effectively detect the current at the main circuit shunt and determine the short-circuit trigger threshold according to the design. 2. Design a short-circuit drive signal self-locking circuit to effectively lock the short-circuit state. Simultaneously, design a delay circuit to release the short-circuit lock after a certain delay, restoring the main circuit to its conducting state. Design an absorption circuit for the delay circuit to quickly release the RC charge state of the delay circuit, enabling faster response to continuous triggering and recovery of the short-circuit protection signal under frequent short-circuit conditions.

[0043] In summary, the present invention provides a battery short-circuit protection circuit, which includes a voltage acquisition circuit, a short-circuit judgment circuit, a main circuit on / off control circuit, and a locking delay circuit. The voltage acquisition circuit acquires the main circuit voltage of the main circuit to be protected, and the short-circuit judgment circuit performs short-circuit detection and outputs a short-circuit judgment signal. Then, the main circuit on / off control circuit controls the on / off state of the main circuit to be protected according to the short-circuit judgment signal. Simultaneously, the locking delay circuit maintains the output state of the short-circuit judgment signal to keep the main circuit to be protected in an off state, thereby enabling short-circuit repair. After a preset time, the locking delay circuit releases the output state of the short-circuit judgment signal, allowing the main circuit to recover, thus achieving self-recovery of the main circuit.

[0044] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A battery short-circuit protection circuit, characterized in that, The circuit includes a voltage acquisition circuit, a short-circuit detection circuit, a main circuit on / off control circuit, and a locking delay circuit. The voltage acquisition circuit is electrically connected to the main circuit to be protected and the short-circuit detection circuit. The short-circuit detection circuit is electrically connected to the main circuit on / off control circuit and the locking delay circuit. The main circuit on / off control circuit is electrically connected to the main circuit to be protected. The voltage acquisition circuit is used to acquire the main circuit voltage of the main circuit to be protected, and its output terminal is connected to the short circuit judgment circuit. The short-circuit detection circuit is used to output a short-circuit detection signal according to the main circuit voltage. It includes a comparator P2, and the output terminal of the comparator P2 is electrically connected to the main circuit on / off control circuit and the locking delay circuit. The main circuit on / off control circuit is used to control the on / off state of the main circuit to be protected according to the short circuit determination signal. The locking delay circuit is used to maintain and release the output state of the short-circuit determination signal after a preset time; The locking delay circuit includes a locking circuit and a delay circuit. The locking circuit is electrically connected to the output terminal of the comparator P2 and is used to maintain the output state of the short circuit determination signal. The delay circuit is electrically connected to the locking circuit and is used to release the output state of the short circuit determination signal after a preset time. The locking circuit includes a diode D1 and a resistor R8. The positive terminal of the diode D1 is electrically connected to the output terminal of the comparator P2, the negative terminal of the diode D1 is electrically connected to one end of the resistor R8, and the other end of the resistor R8 is electrically connected to the positive input terminal of the comparator P2. The lock-in delay circuit further includes diode D2 and NMOS transistor Q4. The delay circuit includes diode D3, resistor R13, resistor R14, and capacitor C2. The anode of diode D2 is electrically connected to the output terminal of comparator P2. The cathode of diode D2 is electrically connected to the cathode of diode D3 and one end of resistor R14. One end of resistor R13 is electrically connected to the anode of diode D3 and the other end of resistor R14. The other end of resistor R13 is grounded. One end of capacitor C2 is electrically connected to the other end of resistor R14 and the gate of NMOS transistor Q4. The other end of capacitor C2 is grounded. The source of NMOS transistor Q4 is grounded. The drain of NMOS transistor Q4 is electrically connected to the positive input terminal of comparator P2.

2. The battery short-circuit protection circuit according to claim 1, characterized in that, The voltage acquisition circuit includes an amplifier P1, both the positive and negative input terminals of which are electrically connected to the main circuit to be protected, and the output terminal of the amplifier P1 is electrically connected to the short-circuit detection circuit.

3. The battery short-circuit protection circuit according to claim 2, characterized in that, The short-circuit detection circuit further includes a reference detection voltage input circuit. The positive and negative input terminals of the comparator P2 are electrically connected to the output terminal of the amplifier P1 and the reference detection voltage input circuit, respectively. The output terminal of the comparator P2 is used to output the short-circuit detection signal.

4. The battery short-circuit protection circuit according to claim 1, characterized in that, The lockout delay circuit further includes an absorption circuit, which includes a transistor Q5 and a resistor R12. The transistor Q5 is a PNP transistor. The base of the transistor Q5 is electrically connected to the output terminal of the comparator P2. The emitter of the transistor Q5 is electrically connected to one end of the resistor R14. The collector of the transistor Q5 is electrically connected to one end of the resistor R12. The other end of the resistor R12 is grounded.

5. The battery short-circuit protection circuit according to claim 3, characterized in that, The main circuit on / off control circuit includes: transistor Q3, resistor R9, transistor Q1, resistor R11, transistor Q2, and resistor R10. Transistor Q3 is an NPN transistor. The base of transistor Q3 is electrically connected to the output terminal of comparator P2, and the emitter of transistor Q3 is grounded. One end of resistor R9 is electrically connected to the power supply input, and the other end of resistor R9 is electrically connected to the collector of transistor Q3 and the base of transistor Q1. Transistor Q1... The transistor Q1 is an NPN type transistor. The emitter of transistor Q1 is grounded, and the collector of transistor Q1 is electrically connected to one end of resistor R11. The other end of resistor R11 is electrically connected to the base of transistor Q2. Transistor Q2 is a PNP type transistor. The collector of transistor Q2 is electrically connected to the on / off control drive terminal in the main circuit to be protected. The emitter of transistor Q2 is electrically connected to one end of resistor R10, and the other end of resistor R10 is electrically connected to the power supply input.

6. The battery short-circuit protection circuit according to claim 2, characterized in that, The voltage acquisition circuit also includes a high-precision shunt, which is connected in series in the main circuit to be protected. The positive and negative input terminals of the amplifier P1 are electrically connected to the two ends of the high-precision shunt, respectively.

7. The battery short-circuit protection circuit according to claim 3, characterized in that, The reference voltage input circuit includes a diode D4, a resistor R7, and a resistor R5. One end of the diode D4 is electrically connected to the power supply input, and the other end of the diode D4 is electrically connected to one end of the resistor R7. The other end of the resistor R7 is electrically connected to one end of the resistor R5, and the other end of the resistor R5 is grounded. One end of the resistor R5 is electrically connected to the negative input terminal of the comparator P2.

Images