Battery protection circuit and battery discharge device

Abstract

Embodiments of the present application disclose a battery protection circuit and a battery discharge device including the battery protection circuit. The battery protection circuit includes an analog switch module, a first control module, a switch unit, and a controller module. The analog switch module is electrically connected between a battery connection terminal and an output terminal, and is used to control the electrical conduction or cut-off between the battery connection terminal and the output terminal. The switch unit is electrically connected to the analog switch module, and is used to output an initial enable signal to control the analog switch module to conduct when receiving an external trigger signal, and at the same time provide a driving power supply for the battery to be transmitted to the output terminal to drive a load. The controller module is electrically connected to the first control module, and is used to output a battery enable signal to control the first control module to conduct when the driving power supply is transmitted to the output terminal. The first control module is electrically connected to the analog switch module, and is used to output a discharge enable signal to control the analog switch module to maintain conduction after the trigger signal disappears when the first control module conducts.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and particularly to a battery protection circuit and a battery discharge device. Background Art

[0002] With the continuous development of battery technology, various batteries are more and more widely used in products. The discharge performance of the batteries used in most products is related to the service life and safety of the products. At present, the control of the battery discharge system in electronic products on the market is mainly divided into two parts: hardware control and software control. In most battery discharge systems, the hardware control system and the software control system are independent of each other and separately protect and control the battery discharge. The hardware circuit is the innermost layer of control and protection of the battery hardware control system, and the software control system is the outermost layer of control and protection.

[0003] After the battery discharges to the termination voltage, continuous discharge is called over-discharge. In the entire battery discharge circuit control system, the software controller and the battery hardware controller consume a relatively high power of the battery, which can reach hundreds of μA or even higher. This not only shortens the service life of the battery, but also causes the battery capacity to decrease and irreversible damage to the battery itself due to over-discharge, and even causes the battery to bulge or catch fire. Summary of the Invention

[0004] To solve the foregoing problems, a battery protection circuit and a battery discharge device are provided to prevent the battery from over-discharging and ensure the safety of the battery.

[0005] In an embodiment of the present application, a battery protection circuit is provided, including:

[0006] An analog switch module, electrically connected between the battery connection terminal and the output terminal, is used to control the electrical conduction or cut-off between the battery connection terminal and the output terminal. The battery connection terminal is used to electrically connect to the battery;

[0007] A switch unit, electrically connected to the analog switch module, is used to output an initial enable signal to control the analog switch module to conduct when receiving an external trigger signal. When the analog switch module conducts, the driving power supply provided by the battery is transmitted to the output terminal to drive the load connected to the output terminal;

[0008] A controller module, electrically connected to the first control module, is used to output a battery enable signal to the first control module and control the first control module to conduct when the driving power supply is transmitted to the output terminal;

[0009] The first control module is electrically connected to the analog switch module and is used to output a discharge enable signal to control the analog switch module to maintain conduction after the trigger signal disappears when the first control module conducts.

[0010] In an embodiment of the present application, a battery discharge device including the aforementioned battery protection circuit is provided.

[0011] Compared with the prior art, in the battery protection circuit disclosed in the embodiment of the present application, the second control module and the switch unit form a NAND gate circuit, and the output initial enable signal temporarily turns on the analog switch module to connect the electrical connection between the battery and the load. At the same time, the regulated power supply module outputs a driving voltage to the controller module according to the input driving power supply, and the controller module outputs a battery enable signal to control the continuous conduction of the analog switch module. When the battery voltage is below the normal operating voltage range, that is, in the over-discharge state, the switch unit is self-locked, and the short-circuit detection module and the first control module form a NOR gate circuit to control the first control module to turn off, and the connection between the battery and the load is disconnected. At this time, the power consumption of the battery in the battery discharge control system is several microamperes or even lower, reducing the loss of the battery caused by the control switch in the battery discharge control system, improving the service life of the battery, reducing the decrease in battery capacity and irreversible damage caused by over-discharge of the battery, and even causing the battery to bulge or catch fire. The safety and reliability of the battery circuit system are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained according to these drawings.

[0013] Figure 1 is a battery discharge device disclosed in an embodiment of the present application;

[0014] Figure 2 is for Figure 1 the block diagram of the battery protection circuit in the structural schematic diagram;

[0015] Figure 3 is for Figure 2 the circuit schematic diagram of the analog switch module in the structural schematic diagram;

[0016] Figure 4 is for Figure 2 the circuit schematic diagram of the switch unit and the first control module in the structural schematic diagram;

[0017] Figure 5 is for Figure 2 the circuit schematic diagram of the second control module in the structural schematic diagram;

[0018] Figure 6 is for Figure 2 the circuit schematic diagram of the controller module in the structural schematic diagram;

[0019] Figure 7 It is for Figure 2 The circuit diagram of the voltage acquisition module in the structural diagram;

[0020] Figure 8 It is for Figure 2 The schematic diagram of the circuit of the voltage-stabilized power supply module in the structural diagram;

[0021] Figure 9 It is for Figure 2 The circuit diagram of the current acquisition module in the structural diagram;

[0022] Figure 10 It is for Figure 2 Circuit diagram of the short-circuit detection module in the structural diagram. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0024] See also Figure 1 , which is a structural diagram of a battery discharge device 10 in one embodiment of the present application, as shown Figure 1 As shown, the battery discharge device 10 includes a battery connection terminal 100, a battery protection circuit 200, and an output terminal 300. Furthermore, the battery connection terminal 100 is electrically connected to the positive and negative battery terminals and is used to receive the battery output voltage and output current. The battery connection terminal 100 includes a positive battery connection terminal 100a and a negative battery connection terminal 100b. The positive battery connection terminal 100a and the negative battery connection terminal 100b cooperate to receive a preset output voltage V1 and a preset output current A1 from the battery. The battery protection circuit 200 is electrically connected to the battery connection terminal 100 and is used to control the conduction or disconnection of the circuit between the load and the battery. The output terminal 300 is electrically connected to the battery protection circuit 200 and includes a first output terminal 300a and a second output terminal 300b. The output terminal 300 is used to output a driving power supply to the load. Furthermore, the battery includes a battery or battery pack and an electronic device module that outputs a regulated power supply.

[0025] See also Figure 2 , which is an embodiment of the present application as Figure 1 FIG. 2 is a circuit block diagram of a battery protection circuit 200. Figure 2As shown in the figure, the battery protection circuit 200 includes: an analog switch module 201, a first control module 202, a switch unit 203, a second control module 204, a controller module 205, a voltage acquisition module 206, a regulated power supply module 207, a current acquisition module 208, and a short-circuit detection module 209. In this embodiment, the battery protection circuit 200 is applied to control the battery or battery pack to supply power to the load, reduce the loss of the control switch to the battery or battery pack in the battery or battery pack discharge control system, improve the service life of the battery or battery pack, reduce the decrease in battery capacity and irreversible damage caused by over-discharge of the battery or battery pack, and even cause the battery or battery pack to bulge or catch fire, and enhance the safety and reliability of the discharge circuit.

[0026] The analog switch module 201 is electrically connected between the battery connection terminal 100 and the output terminal 300, and is used to control the electrical conduction and cut-off between the battery and the output terminal 300. When the battery or battery pack is normally supplying power to the load, the analog switch module 201 is turned on, and the electrical connection between the battery connection terminal 100 and the output terminal 300 is conducted, that is, the battery outputs a driving power supply to the load. When the battery or battery pack has over-discharged or the discharge current is too low, there is no external load, or the load circuit has a short circuit, the analog switch module 201 is turned off to control the electrical cut-off between the battery and the output terminal 300. Further, the analog switch module 201 includes at least one electronic switch to control the conduction and cut-off of the discharge circuit.

[0027] The discharge circuit includes the battery protection circuit 200 and the output terminal 300. The over-discharge of the battery or battery pack means that the discharge voltage of the battery or battery pack is lower than the preset output voltage V1 of the battery or battery pack, and the too-low discharge current means that the output current of the battery or battery pack is lower than the preset output current A1. Continuing to discharge will cause damage to the battery or battery pack and reduce the capacity of the battery or battery pack.

[0028] The first control module 202 is electrically connected to the analog switch module 201, and is used to output a discharge enable signal EN2 to the analog switch module 201 when conducting, and maintain the conduction of the analog switch module 201 after the trigger signal disappears. When the battery or battery pack is normally supplying power to the load, the first control module 202 remains conducting and outputs a first-level discharge enable signal EN21. When the battery or battery pack has over-discharged or the discharge current is too low, the discharge circuit has a short circuit, and there is no current at the output terminal 300, the first control module 202 outputs a second-level discharge enable signal EN22 to control the analog switch module 201 to turn off, reduce the loss of the discharge circuit to the battery, and improve the safety and reliability of the battery and the discharge circuit.

[0029] The first-level discharge enable signal EN21 is a high-level discharge enable signal, the second-level discharge enable signal EN22 is a low-level discharge enable signal, and the discharge enable signal EN2 includes the first-level discharge enable signal EN21 and the second-level discharge enable signal EN22.

[0030] The switch unit 203 is electrically connected to the analog switch module 201 and is configured to output an initial enable signal EN1 to control the conduction of the analog switch module 201 when receiving an external trigger signal. When the analog switch module 201 is conducting, the driving power supply provided by the battery is transmitted to the output terminal 300 to drive the load connected to the output terminal. When the discharge circuit is in the sleep state, the switch unit 203 outputs the initial enable signal EN1 to turn on the analog switch module 201 within the first time period T1 and outputs the driving power supply to the output terminal 300. The discharge control circuit operates normally within the first time period T1. If the battery is over-discharged or there is no output current in the discharge circuit, the switch unit 203 fails and will not output the initial enable signal EN1 after conduction. The switch unit 203 includes at least one normally-off control button or a module composed of multiple buttons, and the first time period T1 is the time maintained by the button conduction.

[0031] The second control module 204 is electrically connected to the switch unit 203 and the first control module 202. The second control module 204 is also electrically connected to the battery positive connection terminal 100a and the battery negative connection terminal 100b, and is configured to output a button enable signal DO to the switch unit 203 and the first control module 202 when the preset output voltage V1 and the preset output current A1 are within a preset range, so as to maintain the switch unit 203 and the first control module 202 in a conducting or non-conducting state. The second control module 204 and the switch unit 203 and the first control module 202 form a NAND gate circuit, which is used to control the switch unit 203 to realize the self-locking of the discharge circuit when the discharge circuit is in a short-circuit state or the battery is over-discharged. The second control module 204 and the first control module 202 form a NAND gate circuit. Only when both the second control module 204 and the first control module 202 are electrically conducting, the first control module 202 outputs the first-level discharge enable signal EN21 to control the conduction of the analog switch module 201.

[0032] When the battery is operating normally, the second control module 204 continuously outputs a first-level key enable signal DO1. When there is no output current in the discharge circuit or the battery is over-discharged, the second control module 204 outputs a second-level key enable signal DO2 to turn off the switch unit 203 and the first control module 202, preventing the switch unit 203 from being turned on due to misoperation or the first control module 202 from being turned on due to a circuit fault, which may damage the battery and the discharge circuit. When the circuit is in a self-locked state, that is, when the second control module 204 is in a closed state, the initial enable signal EN1 output by the switch unit 203 is an invalid control signal, and the first-level discharge enable signal EN21 output by the first control module 202 is an invalid control signal.

[0033] The first-level key enable signal DO1 is a high-level key enable signal, and the second-level key enable signal DO2 is a low-level key enable signal. The key enable signal DO includes the first-level key enable signal DO1 and the second-level key enable signal DO2.

[0034] The controller module 205 is electrically connected to the first control module 202 and the voltage module 206, and is used to output a battery enable signal OP to control the conduction and cut-off of the first control module 202 when receiving the driving voltage Vcc, and output a voltage acquisition enable signal BT to control the voltage acquisition module 206 to continuously output a voltage acquisition signal VSN. When the discharge circuit is operating normally, the controller module 205 outputs a battery enable signal OP to control the conduction of the first control module 202. When there is no external output current, that is, when the discharge circuit is in a sleep state, or when the discharge current is lower than the preset output current A1, the controller module 205 stops outputting the battery enable signal OP after a delay time of T2, and the analog switch module 201 is electrically disconnected, reducing the power consumption of the electronic devices in the discharge circuit on the battery power and improving the battery usage time.

[0035] The voltage acquisition module 206 is electrically connected to the controller module 205 and is also electrically connected between the battery positive connection terminal 100a and the battery negative connection terminal 100b, and is used to monitor the battery voltage in real time and output a voltage acquisition signal VSN to the controller module 205. When the battery is over-discharged, the voltage value of the battery is lower than the preset output voltage V1. After the voltage acquisition signal VSN output by the voltage acquisition module 206 is logically calculated by the controller module 205, it is determined whether the battery is over-discharged. If the battery or the battery pack is over-discharged, the battery enable signal OP is stopped from being output to control the first control module 202 to turn off, avoiding the reduction of the battery service life due to battery over-discharge.

[0036] The voltage stabilizer power supply module 207 is electrically connected to the controller module 205 and the battery negative connection terminal 100b, and is used to provide a driving voltage Vcc to the controller module 205. In the sleep state of the discharge circuit, the voltage stabilizer power supply module 207 has no input voltage. If the switch unit 203 outputs an initial enable signal EN1 to control the conduction of the analog switch module 201 within the first time period T1, the driving power supply is output to the voltage stabilizer power supply module 207, controlling the voltage stabilizer power supply module 207 to output the driving voltage Vcc to the controller module 205, driving the controller module 205 to work, and then controlling the first control module 202 to conduct. After the switch unit 203 is turned off, the analog switch module 201 remains conductive continuously.

[0037] The current acquisition module 208 is electrically connected between the controller module 205 and the battery negative connection terminal 100b and the second output terminal 300b, and is used to output a current acquisition signal ISN to the controller module 205. If there is no output current in the discharge circuit or the discharge current is lower than the preset output current A1, the controller module 205 outputs a battery enable signal OP according to the received output current acquisition signal ISN to control the first control module 202 to turn off, and then controls the analog switch module 201 to cut off. The discharge circuit is in an off state, reducing the power consumption of the battery by the discharge control circuit and improving the battery service life.

[0038] The short - circuit detection module 209 is electrically connected to the first control module 202 and is also electrically connected between the battery negative connection terminal 100b and the second output terminal 300b. When the output terminal current is greater than the preset short - circuit current A2, it outputs a short - circuit interruption signal EN3 to control the first control module 202 to be electrically cut off. The short - circuit detection module 209 and the first control module 202 form a NOR gate circuit, which is used to control the conduction and cut - off of the first control module 202. Further, when the discharge circuit is working normally, the short - circuit detection module 209 has no output signal, and the battery enable signal OP output by the controller module 205 controls the first control module 202 to conduct. When a short - circuit occurs in the discharge circuit, the short - circuit detection module 209 outputs a short - circuit interruption signal EN3 to the first control module 202, controlling the first control module 202 to change from the conductive state to the cut - off state, and then turning off the analog switch module 201, reducing the damage to the battery caused by the short - circuit of the discharge circuit and improving the safety of the discharge circuit.

[0039] When the discharge circuit has no output current or is in a sleep state, the switch unit 203 outputs an initial enable signal EN1 to control the conduction of the analog switch module 201 within the first time period T1, and the regulated power supply module 207 outputs a driving voltage Vcc to drive the controller module 205 to work. When the switch unit 203 has no output signal, the first control module 202 controls the analog switch module 201 to conduct, keeping the discharge circuit conducting. The second control module 204 and the switch unit 203 form a NAND gate circuit. When the battery is over-discharged or there is no output current in the discharge circuit, the second control module 204 is turned off, and the initial enable signal EN1 output by the switch unit 203 becomes invalid, that is, the switch unit 203 realizes self-locking, and the controller module 205 stops outputting the battery enable signal OP to control the first control module 202 to cut off, turning off the electrical connection between the battery connection terminal 100 and the output terminal 300.

[0040] The voltage acquisition module 206, the controller module 205, and the current acquisition module 208 constitute an analog data acquisition system. Based on the received voltage acquisition signal VSN and current acquisition signal ISN, after logical calculation by the processing unit in the controller module 205, the controller module 205 determines whether the battery voltage and current are lower than the preset output voltage V1 or the discharge current is lower than the preset output current A1. If the battery is in a normal working state, it outputs a battery enable signal OP to control the first control module 202 to conduct. If the battery is over-discharged or the discharge current is lower than the preset output current A1, it controls the first control module 202 to cut off. On the other hand, the short-circuit detection module 209 and the first control module 202 form a NOR gate circuit. When a short circuit occurs in the discharge circuit, the short-circuit detection module 209 outputs a short-circuit detection signal EN3 to control the first control module 202 to cut off, so as to turn off the analog switch module 201.

[0041] The battery protection circuit protects the battery and the load, minimizing the power consumption of the discharge control circuit for the battery or battery pack to the greatest extent. At the same time, it reduces the control quantity of the peripheral analog switch control module, reduces the loss of the discharge control circuit for the battery or battery pack, reduces the probability of battery damage, and improves the safety and reliability of the battery.

[0042] More specifically, please refer to Figure 3 which is Figure 2 a schematic diagram of the analog switch circuit module in the structural schematic diagram. As Figure 3 shown, the analog switch module circuit 201 includes a battery positive connection terminal B+, an electronic switch Q1, a first voltage connection terminal VBAT, a load positive connection terminal P+, a second resistor R2, and a fourth resistor R4.

[0043] The battery positive connection terminal B+ is the positive terminal of the input battery. The first terminal of the electronic switch Q1 is electrically connected to the battery positive connection terminal B+. The second terminal of the electronic switch Q1 is electrically connected to the load positive connection terminal P+. The load positive connection terminal P+ is electrically connected to the first output terminal 300a. The third terminal of the electronic switch Q1 is electrically connected to the fourth resistor R4. The second resistor R2 is electrically connected between the battery positive connection terminal B+ and the third terminal of the electronic switch Q1. The fourth resistor R4 is electrically connected between the third terminal of the electronic switch Q1 and the first connection terminal N1. The first connection terminal N1 is the connection point of the analog switch 201, the switch unit, and the first control circuit 202.

[0044] The first terminal of the electronic switch Q1 is the battery input terminal, the second terminal of the electronic switch Q1 is the battery output terminal, and the third terminal of the electronic switch Q1 is the drive signal control terminal.

[0045] Specifically, the electronic switch Q1 is a low-voltage drive electronic switch used to control the conduction or cut-off of the discharge circuit. If the battery and the discharge circuit work normally, the electronic switch Q1 conducts, and the positive terminal of the battery inputs direct current to the discharge control circuit, the first voltage connection terminal VBAT, and the load positive connection terminal P+. If the battery is over-discharged, the discharge current is lower than the preset output current A1, or the discharge circuit is short-circuited, the electronic switch Q1 disconnects to protect the safety of the battery and the discharge circuit. The electronic switch Q1 includes a P-type transistor and a relay. The first voltage connection terminal VBAT is the input terminal of the voltage stabilization power supply module 207( Figure 2 ).

[0046] More specifically, please refer to Figure 4 , which is Figure 2 the schematic diagram of the switch unit and the first control module circuit in the structural schematic diagram. As Figure 4 shown, the switch unit and the first control module circuit 202 include a switch control circuit 2021, a first control circuit 2022, a battery enable connection terminal OP EN, and a short circuit interruption connection terminal Short INT.

[0047] The switch control circuit 2021 is used to control the conduction of the analog switch circuit 201 and includes a fourth diode D4, a first push-button switch S1, and a fourth capacitor C4.

[0048] The first terminal of the first push-button switch S1 is electrically connected to the cathode of the fourth diode D4. The anode of the fourth diode D4 is electrically connected to the first connection terminal N1. The second terminal of the first push-button switch S1 is electrically connected to the third connection terminal N3. The fourth capacitor C4 is electrically connected between the first terminal and the third connection terminal N3 of the first push-button switch S1. The first terminal of the first push-button switch S1 is the input terminal, that is, the input voltage terminal when the first push-button switch S1 conducts. The second terminal of the first push-button switch S1 is the output terminal, that is, the output voltage terminal when the first push-button switch S1 conducts.

[0049] The first control circuit 2022 is used to control the on and off of the analog switch circuit 201, and includes a second diode D2, a seventh resistor R7, an eighth resistor R8, and a fourth transistor Q4.

[0050] The gate of the fourth transistor Q4 is electrically connected to the short circuit interruption connection terminal Short INT, the source of the fourth transistor Q4 is electrically connected to the first connection terminal N1, the drain of the fourth transistor Q4 is electrically connected to the third connection terminal N3, the anode of the second diode D2 is electrically connected to the battery enable connection terminal OP EN, the cathode of the second diode D2 is electrically connected to the seventh resistor R7, the seventh resistor R7 is electrically connected between the cathode of the second diode D2 and the short circuit interruption connection terminal Short INT, and the eighth resistor R8 is electrically connected between the short circuit interruption connection terminal Short INT and the third connection terminal N3. Further, the first connection terminal N1 is connected to the analog switch circuit 201.

[0051] Specifically, the first key switch S1 is a normally open key controller. When the discharge circuit is in the sleep state, the first key switch S1 is turned on by an external trigger signal, the first connection terminal N1 changes from a high level to a low level, driving the electronic switch Q1 to conduct within the first time period T1. At the same time, a high-level battery enable signal OP is input to the battery enable connection terminal OP to drive the fourth transistor Q4 to conduct. After the first key switch S1 is turned off, the fourth transistor Q4 remains in the conducting state, controlling the electronic switch Q1 to continuously conduct. If a short circuit occurs in the discharge circuit, the short circuit interruption connection terminal Short INT drops from a high level to a low level, pulling the battery enable signal OP down to a low level, and the fourth transistor Q4 is turned off, controlling the electronic switch Q1 to disconnect the connection between the battery, the discharge control circuit, and the load, and no current is input to the discharge circuit. If there is no output current in the discharge circuit or no current in the circuit, a low-level battery enable signal OP is input to the battery enable connection terminal OP to turn off the fourth transistor Q4, that is, to control the electronic switch Q1 to disconnect the connection between the battery, the discharge control circuit, and the load, reducing the consumption of the battery by the electronic devices in the discharge circuit and increasing the battery usage time.

[0052] The third connection terminal N3 is the connection end point of the switch unit, the first control module circuit 202, and the second control module 204. The fourth transistor Q4 is an N-type transistor. The sleep state of the discharge circuit means that there is no output current from the discharge circuit to the load.

[0053] More specifically, please refer to Figure 5 which is Figure 2 the schematic diagram of the second control module circuit in the structural schematic diagram. As Figure 5As shown, the second control module circuit 204 includes a fifth transistor Q5, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a first voltage-dividing resistor RS1, a twenty-second resistor R22, a fifth capacitor C5, a twelfth capacitor C12, an eighth diode D8, and a discharge control unit U2.

[0054] The discharge control unit U2 is an integrated circuit, and is configured to control the electrical conduction or cutoff of the fifth transistor Q5 according to the output voltage of the battery connection terminal 100. The discharge control unit U2 includes pins 1 - 6, and the functions are as follows: Pin 1 of the discharge control unit U2 is the battery charging control pin, pin 2 of the discharge control unit U2 is the delay time measurement pin, pin 3 of the discharge control unit U2 is the battery current overcurrent detection pin, pin 4 of the discharge control unit U2 is the voltage input pin, pin 5 of the discharge control unit U2 is the discharge control output pin, and pin 6 of the discharge control unit U2 is the ground terminal.

[0055] The source of the fifth transistor Q5 is electrically connected to the third connection terminal N3, the drain of the fifth transistor Q5 is electrically connected to the battery negative terminal B-, the gate of the fifth transistor Q5 is electrically connected to the cathode of the eighth diode D8, the anode of the eighth diode D8 is serially connected to the tenth resistor R10 and electrically connected to pin 5 of the discharge control unit U2, the twenty-second resistor R22 is electrically connected between any point between the anode of the eighth diode D8 and the tenth resistor R10 and the cathode of the eighth diode D8, the twelfth capacitor C12 is electrically connected between any point between the gate of the fifth transistor Q5 and the cathode of the eighth diode D8 and the battery negative terminal B-, the eleventh resistor R11 is electrically connected between pin 3 of the discharge control unit U2 and the second connection terminal N2, the first voltage-dividing resistor RS1 is electrically connected between the second connection terminal N2 and the battery negative terminal B-, the ninth resistor R9 is electrically connected between the battery positive connection terminal B+ and pin 4 of the discharge control unit U2, the fifth capacitor C5 is electrically connected between pin 4 of the discharge control unit U2 and pin 6 of the discharge control unit U2, and pin 4 of the discharge control unit U2 is electrically connected to any connection point between the ninth resistor R9 and the fifth capacitor C5.

[0056] The first control circuit 2022 and the switch control circuit 2021 respectively form a NAND gate circuit with the second control module circuit 204. When the discharge circuit is working properly, the discharge control unit U2 outputs a high-level key enable signal DO through pin 5 to control the fifth transistor Q5 to conduct. When the first control circuit 2022 conducts, the current passes through the drain of the fourth transistor Q4 in the first control circuit 2022 and is output to the source of the fifth transistor Q5 and finally reaches the negative terminal B- of the battery. When the first switch S1 in the switch control circuit 2021 conducts, the current passes through the fifth transistor Q5 and is output to the negative terminal B- of the battery. The first switch S1 pulls down the gate voltage of the first electronic switch Q1 to control the first electronic switch Q1 in the analog switch module circuit 201 to conduct.

[0057] When the battery is over-discharged, the battery discharge current is lower than the preset output current A1, or the discharge circuit is in a sleep state, the discharge control unit U2 outputs a low-level key enable signal DO through pin 5 to control the fifth transistor Q5 to turn off. At this time, whether the first switch S1 is on or off, it cannot drive the first electronic switch Q1 to conduct, realizing the self-locking of the first switch S1. In this embodiment, the discharge control unit U2 can be implemented by S261DAY, and the fifth transistor Q5 is an N-type transistor.

[0058] More specifically, please refer to Figure 6 , which is Figure 2 a schematic diagram of the controller module circuit in the structural schematic diagram. As Figure 6 shown, the controller module circuit 205 includes a micro control unit U4. The micro control unit U4 includes a battery enable connection terminal OP EN, a current detection terminal DIS ISN, a voltage detection terminal BAT VSN, a voltage detection enable terminal BAI EN, and a drive voltage terminal VCC.

[0059] The battery enabling connection terminal OP EN is electrically connected to the first control circuit 2022, and is used to output a high-level battery enabling signal OP to control the fourth transistor Q4 to conduct when the discharge circuit is working properly. If the battery is over-discharged or the discharge current is lower than the normal current value I, a low-level battery enabling signal OP is output to control the fourth transistor Q4 to cut off. The current detection terminal DIS ISN is electrically connected to the short-circuit detection circuit 209 and is used to receive the current acquisition signal ISN in real time. After logical operation by the microcontroller unit U4, it is determined whether the battery current is lower than the preset output current A1. The voltage detection terminal BAT VSN and the voltage detection enabling terminal BAI EN are electrically connected to the voltage acquisition module circuit 206. The voltage detection terminal BAT VSN is used to receive the voltage acquisition signal VSN in real time. After logical operation by the microcontroller unit U4, it is determined whether the battery voltage is over-discharged. The voltage detection enabling terminal BAI EN is used to output a voltage acquisition enabling signal BT to the voltage acquisition module circuit 206 to drive the voltage acquisition module circuit 206 to output the voltage acquisition signal VSN. The driving voltage terminal VCC is electrically connected to the voltage stabilizing power supply module circuit 207 and is used to input the driving voltage Vcc to the microcontroller unit U4.

[0060] More specifically, please refer to Figure 7 , which is Figure 2 a schematic diagram of the voltage acquisition module circuit in the structural schematic diagram. As Figure 7 shown, the voltage acquisition module circuit 206 includes a fourteenth resistor R14, a fifteenth resistor R15, an eighteenth resistor R18, a sixth transistor Q6, an eighth transistor Q8, a second diode D2, a second capacitor C2, a voltage detection enabling terminal BAI EN, and a voltage detection terminal BAT VSN.

[0061] The fourteenth resistor R14 is electrically connected between the battery positive connection terminal B+ and the collector of the eighth transistor Q8. The base of the eighth transistor Q8 is electrically connected to the voltage detection enabling terminal BAI EN. The emitter of the eighth transistor Q8 is electrically connected to the battery negative connection terminal B-. The gate of the sixth transistor Q6 is electrically connected to any connection point between the fourteenth resistor R14 and the collector of the eighth transistor Q8. The source of the sixth transistor Q6 is electrically connected to the battery positive connection terminal B+. The drain of the sixth transistor Q6 is electrically connected to the fifteenth resistor R15. The fifteenth resistor R15 is electrically connected between the drain of the sixth transistor Q6 and the voltage detection terminal BAT VSN. The eighteenth resistor R18 is electrically connected between the voltage detection terminal BAT VSN and the battery negative terminal B-. The anode of the second diode D2 is electrically connected to the voltage detection terminal BAT VSN. The cathode of the second diode D2 is electrically connected to the driving voltage terminal VCC. The second capacitor C2 is electrically connected between the voltage detection terminal BAT VSN and the second ground terminal SGND.

[0062] The voltage acquisition module circuit 206 is mainly used to detect in real time whether the battery is over-discharged. The voltage acquisition enable signal BT output by the voltage detection terminal BATVSN controls the eighth transistor Q8 to conduct. Therefore, the gate of the sixth transistor Q6 is connected to the negative connection terminal B- of the battery to drive the sixth transistor Q6 to conduct. After the battery voltage is divided by the fifteenth resistor R15, the voltage acquisition signal VSN is output from the voltage detection terminal BAT VSN to the controller unit 205. After the controller unit 205 performs logical calculation on the voltage acquisition signal VSN, it determines whether the battery is in an over-discharged state. If the battery is in an over-discharged state, the controller unit 205 controls the first control circuit 2022 to cut off, and the switch control circuit 2021 is electrically disconnected.

[0063] In this embodiment, the sixth transistor Q6 is a P-type transistor, and the eighth transistor Q8 is an NPN-type transistor. The voltage value of the driving voltage terminal VCC is within 4.7V - 5.3V, and the second ground terminal SGND is the ground terminal of the electronic module in the discharge control circuit.

[0064] More specifically, please refer to Figure 8 , which is Figure 2 the schematic diagram of the regulated power supply module circuit in the structural schematic diagram. As Figure 8 shown, the regulated power supply module circuit 207 includes a first diode D1, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth resistor R4, and a voltage regulation control unit U1.

[0065] In this embodiment, the voltage regulation control unit U1 is an integrated circuit, including pins 1 - 3, and the functions are as follows: Pin 1 of the voltage regulation control unit U1 is the ground terminal, pin 2 of the voltage regulation control unit U1 is the input voltage terminal, and pin 3 of the voltage regulation control unit U1 is the output voltage terminal.

[0066] The anode of the first diode D1 is electrically connected to the first voltage connection terminal VBAT, the cathode of the first diode D1 is electrically connected to the first capacitor C1, the first capacitor C1 is electrically connected between the cathode of the first diode D1 and the negative terminal B- of the battery, the third capacitor C3 is electrically connected between pin 2 of the voltage regulation control unit U1 and the negative terminal B- of the battery, the fourth resistor R4 is electrically connected between pin 1 of the voltage regulation control unit U1 and the negative terminal B- of the battery, the second capacitor C2 is electrically connected between pin 3 of the voltage regulation control unit U1 and pin 1 of the voltage regulation control unit U1. Further, pin 1 of the voltage regulation control unit U1 is electrically connected to the second ground terminal SGND, pin 2 of the voltage regulation control unit U1 is electrically connected to any point between the first diode D1 and the first capacitor C1, and pin 3 of the voltage regulation control unit U1 is electrically connected to the driving voltage terminal VCC.

[0067] In the discharge circuit, the switch control circuit 2021 outputs an initial enable signal EN1 to control the conduction of the first electronic switch Q1. The battery voltage is input to pin 2 of the voltage stabilization control unit U1. At the same time, the driving voltage Vcc is output from pin 3 of the voltage stabilization control unit U1 to the micro-control module circuit 205, driving the micro-control unit U4 to output a high-level discharge enable signal OP to control the conduction of the first control circuit 2022. After the first key switch S1 is turned off, the discharge circuit remains conductive. In this embodiment, the voltage stabilization control unit U1 can be implemented using ME6203A.

[0068] More specifically, please refer to Figure 9 , which is Figure 2 a schematic diagram of the current acquisition module circuit in the structural schematic diagram. As Figure 9 shown, the current acquisition module circuit 208 includes the twelfth resistor R12, the sixteenth resistor R16, the nineteenth resistor R19, the twentieth resistor R20, the twenty-first resistor R21, the sixth capacitor C6, the seventh capacitor C7, the eighth capacitor C8, the eleventh capacitor C11, the fifth diode D5, the sixth diode D6, the seventh diode D7, the eighth diode D8, and the amplifier U3.

[0069] The sixteenth resistor R16 is electrically connected between the battery negative terminal connection B- and pin 2 of the amplifier U3. The twentieth resistor R20 is electrically connected between the first ground terminal GND and pin 3 of the amplifier U3. The anode of the fifth diode D5 is electrically connected to the driving voltage terminal VCC, and the cathode of the fifth diode D5 is electrically connected to pin 2 of the amplifier U3. The anode of the sixth diode D6 is electrically connected to pin 3 of the amplifier U3, and the cathode of the sixth diode D6 is electrically connected to the driving voltage terminal VCC. The cathode of the seventh diode D7 is electrically connected to pin 2 of the amplifier U3, and the anode of the seventh diode D7 is electrically connected to the second ground terminal SGND. The anode of the eighth diode D8 is electrically connected to pin 3 of the amplifier U3, and the cathode of the eighth diode D8 is electrically connected to the second ground terminal SGND. The twelfth resistor R12 and the sixth capacitor C6 are connected in parallel between any point between pin 2 of the amplifier U3 and pins 1 and 19 of the amplifier U3. The seventh capacitor C7 and the eighth capacitor C8 are connected in parallel between the driving voltage terminal VCC and the second ground terminal SGND. The twenty-first resistor R21 and the eleventh capacitor C11 are connected in series between pin 3 of the amplifier U3 and the current detection terminal DIS ISN. The nineteenth resistor R19 is electrically connected between pin 1 of the amplifier U3 and the current detection terminal DIS ISN. Pin 4 of the amplifier U3 is electrically connected to the second ground terminal SGND. Further, the second ground terminal SGND is electrically connected to any connection point between the twenty-first resistor R21 and the eleventh capacitor C11. Pin 5 of the amplifier U3 is electrically connected to the driving voltage terminal VCC.

[0070] In this embodiment, the amplifier U3 is an integrated circuit, including pins 1 to 5, and their functions are as follows: Pin 1 of the amplifier U3 is the operational amplification result output terminal, pin 2 of the amplifier U3 is the current output terminal, pin 3 of the amplifier U3 is the current input terminal, pin 4 of the amplifier U3 is the ground terminal, and pin 5 of the amplifier U3 is the voltage input terminal. Further, the amplifier U3 can be implemented by TP1542.

[0071] The current acquisition module circuit 208 is used to collect the current of the discharge circuit in real time and output the current detection signal ISN to the controller module circuit 205. If there is no output current in the discharge circuit, or there is no current in the discharge circuit, and the battery discharge current is lower than the preset output current A1, the microcontroller unit U4 outputs a low-level battery enable signal OP according to the output current detection signal ISN to control the first control circuit 2022 to turn off.

[0072] More specifically, please refer to Figure 10 , which is Figure 2 a schematic diagram of the short-circuit detection circuit in the structural schematic diagram. As Figure 10 shown, the short-circuit detection circuit 209 includes the thirteenth resistor R13, the seventeenth resistor R17, the seventh capacitor C7, and the seventh transistor Q7.

[0073] The thirteenth resistor R13 and the seventeenth resistor R17 are connected in series between the second connection terminal N2 and the battery negative connection terminal B-. The seventh capacitor C7 is electrically connected between the base of the seventh transistor Q7 and the battery negative connection terminal B-. The base of the seventh transistor Q7 is electrically connected to any connection point between the thirteenth resistor R13 and the seventeenth resistor R17. The collector of the seventh transistor Q7 is electrically connected to the short-circuit interruption connection terminal Short INT, and the emitter of the seventh transistor Q7 is electrically connected to the battery negative connection terminal B-.

[0074] Further, in the short-circuit detection circuit 209, the second connection terminal N2 is connected to the first ground terminal GND. If a short circuit occurs in the discharge circuit, the current in the second output terminal 300b ( Figure 2 ) is input to the battery negative connection terminal 100b through the first ground terminal GND, and the short-circuit current is input to the short-circuit detection circuit 209 through the second connection terminal N2. When a short circuit occurs in the discharge circuit, the short-circuit current flows from the second connection terminal N2 to the battery negative terminal B-. Therefore, the current between the thirteenth resistor R13 and the seventeenth resistor R17 in the short-circuit detection circuit 209 increases. When the base current of the seventh transistor Q7 is greater than the preset short-circuit current A2, the seventh transistor Q7 conducts, and the short-circuit interruption connection terminal Short INT and the battery negative connection terminal B- conduct. The short-circuit interruption connection terminal Short INT becomes low level to control the fourth transistor Q4 to turn off, and the electronic switch Q1 between the discharge control circuit and the load and the battery is disconnected, ensuring the safety and reliability of the discharge circuit.

[0075] In this embodiment, the short - circuit detection circuit 209 and the first control circuit 2022 form a NOR gate circuit. The short - circuit detection circuit 209 pulls down the battery enable connection terminal OP EN to a low level through the short - circuit interruption connection terminal Short INT, and the fourth transistor Q4 in the first control circuit 2022 is cut off, thereby controlling the electronic switch Q1 to turn off. The first ground terminal GND represents the load ground terminal. The seventh transistor Q7 is an N - type transistor. The preset short - circuit current A2 is a preset current value, and the magnitude of the preset short - circuit current A2 depends on the rated current of the load.

[0076] In this embodiment, after the first key switch S1 in the switch control circuit 2021 is turned on, it controls the electronic switch Q1 in the analog switch module circuit 201 to turn on. The voltage - stabilizing control unit U1 in the voltage - stabilizing power supply module circuit 207 outputs the driving voltage Vcc to the controller module circuit 205. The controller module circuit 205 outputs a battery enable signal OP to control the fourth transistor Q4 in the first control circuit 2022 to turn on. After the first key switch S1 is turned off, the electronic switch Q1 is maintained in a conducting state. When there is no load outside the battery, the controller module circuit 205 outputs a low - level battery enable signal OP to control the fourth transistor Q4 to be electrically disconnected.

[0077] If the battery is in an over - discharge state, the voltage acquisition signal VSN output by the voltage acquisition module circuit 206 is sent to the controller module circuit 205. After logical calculation by the controller module circuit 205, if the battery voltage value is lower than the lowest discharge voltage V1, the micro - control unit U4 outputs a low - level battery enable signal OP to control the fourth transistor Q4 to be electrically disconnected. If the battery discharge current is lower than the preset output current A1, the current acquisition signal ISN output by the current acquisition module circuit 208 is sent to the controller module circuit 205. After logical calculation by the controller module circuit 205, if it is determined that the battery discharge current is lower than the preset output current A1, then the fourth transistor Q4 is controlled to be electrically disconnected. If the discharge circuit is short - circuited, the short - circuit detection module circuit 209 outputs a short - circuit interruption signal EN3 to control the fourth transistor Q4 to be electrically disconnected.

[0078] Through the battery protection circuit, the power consumption of the peripheral circuit on the battery or battery pack is reduced. At the same time, the number of controls of the peripheral analog switch control module is reduced, the probability of battery damage is reduced, and the safety and reliability of the entire discharge circuit are improved.

[0079] The above has introduced in detail a battery protection circuit disclosed in the embodiments of the present application. Specific examples are used in this article to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application; at the same time, for those of ordinary skill in the art, according to the idea of the present application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A battery protection circuit, characterized in that, Comprising: A simulation switch module, electrically connected between the battery connection terminal and the output terminal, for controlling the electrical conduction or cut-off between the battery connection terminal and the output terminal, and the battery connection terminal is used for electrically connecting to a battery; A switch unit, electrically connected to the simulation switch module, for outputting an initial enable signal to control the conduction of the simulation switch module when receiving an external trigger signal. When the simulation switch module is conducting, the driving power supply provided by the battery is transmitted to the output terminal to drive a load connected to the output terminal; A controller module, electrically connected to a first control module, for outputting a battery enable signal to the first control module and controlling the conduction of the first control module when the driving power supply is transmitted to the output terminal, and controlling the first control module to turn off when not outputting the battery enable signal; The first control module is electrically connected to the simulation switch module, for outputting a discharge enable signal to control the simulation switch module to maintain conduction after the trigger signal disappears when the first control module is conducting; Wherein, the battery connection terminal includes a battery positive connection terminal and a battery negative connection terminal, and the battery positive connection terminal and the battery negative connection terminal cooperate to receive a preset output voltage and a preset output current from the battery; The battery protection circuit further includes: A second control module, electrically connected to the switch unit and the first control module, and also electrically connected between the battery positive connection terminal and the battery negative connection terminal, for outputting a key enable signal to the switch unit and the first control module to maintain the switch unit and the first control module in a conducting state when the preset output voltage and the preset output current are within a preset range; A regulated power supply module, electrically connected to the controller module, and also electrically connected to a first output terminal and the battery negative connection terminal, for outputting a driving voltage to the controller module to control the controller module to output the battery enable signal when the simulation switch module conducts and outputs the driving power supply to the first output terminal.

2. The battery protection circuit according to claim 1, wherein Further comprising: A voltage acquisition module, electrically connected to the controller module, and also electrically connected between the battery positive connection terminal and the battery negative connection terminal. The controller module continuously outputs a voltage acquisition enable signal to the voltage acquisition module based on the driving voltage in the driving power supply, and the voltage acquisition module outputs a voltage acquisition signal to the controller module according to the received voltage acquisition enable signal; A current acquisition module, electrically connected between the battery negative connection terminal and a second output terminal, for detecting the output terminal current and outputting a current acquisition signal to the controller module. When the battery output current is abnormal, the controller module outputs a second-level battery enable signal; A short-circuit detection module, electrically connected to the first control module, and also electrically connected between the battery negative connection terminal and the second output terminal, for outputting a short-circuit interruption signal to control the electrical cut-off of the first control module when the load circuit is short-circuited.

3. The battery protection circuit according to claim 2, wherein, The first control module and the short-circuit detection module form a NOR gate circuit, which is used to control the first control module to conduct when the first control module is conducting and the short-circuit detection module is disconnected, and to control the first control module to be electrically cut off when the first control module is cut off or the short-circuit detection module is conducting; The switch unit and the second control module form a NAND gate circuit, which is used to control the analog switch module to conduct when the switch unit and the second control module are both conducting, and to maintain the switch unit in an electrically disconnected state when the second control module is electrically disconnected; The first control module and the second control module form a NAND gate circuit, which is used to control the analog switch module to conduct when the first control module and the second control module are both conducting, and to maintain the analog switch module in an electrically cut-off state when the first control module or the second control module is electrically disconnected.

4. The battery protection circuit according to claim 3, wherein The first control module conducts according to the received first-level battery enable signal to control the analog switch module to conduct; the first control module cuts off according to the received second-level battery enable signal to control the analog switch module to be electrically cut off.

5. The battery protection circuit according to claim 4, wherein The battery enable signal is at the first level when the battery is working normally, and is at the second-level signal when the battery is over-discharged; When the battery discharge current is lower than the preset output current and the load circuit is short-circuited, the battery enable signal is the second-level signal.

6. The battery protection circuit according to claim 5, characterized in that, The analog switch module includes at least one P-type transistor, the gate and source of the P-type transistor are electrically connected to the battery positive connection end, and the drain of the P-type transistor is electrically connected to the first output end.

7. The battery protection circuit according to claim 6, characterized in that The first control module includes at least one N-type transistor, the gate of the N-type transistor is electrically connected to the controller module and the short-circuit detection module, the source of the N-type transistor is electrically connected to the analog switch module, and the drain of the N-type transistor is electrically connected to the second control module.

8. The battery protection circuit according to claim 7, wherein The switch unit includes at least one push-button switch, and the push-button switch is a normally open push-button switch. The switch unit conducts when receiving the external trigger signal, and maintains an electrically disconnected state when not receiving the external signal trigger.

9. The battery protection circuit according to claim 8, wherein, The second control module includes at least one N-type transistor and at least one discharge control unit. The source of the N-type transistor is electrically connected to the switch unit and the first control module, the gate of the N-type transistor is electrically connected to the discharge control unit, and the drain of the N-type transistor is electrically connected to the battery negative connection end; The discharge control unit is used to control the N-type transistor to conduct or cut off according to the output voltage of the battery connection end.

10. The battery protection circuit according to claim 9, characterized in that, When the battery discharge voltage is lower than the preset output voltage and there is no output current at the output end, the second control module outputs a second-level key enable signal to maintain the switch unit in a cut-off state.

11. The battery protection circuit according to any one of claims 5-10, characterized in that, The switch unit conducts within the first time period to control the analog switch module to conduct, and the battery is electrically connected to the output end; During the first time period, the regulated power supply module drives the controller module to output the first-level battery enable signal to control the conduction of the first control module, and maintains the conduction of the first control module after the switch unit is electrically disconnected.

12. A battery discharge device, characterized in that, It includes the battery protection circuit according to claim 11, and further includes the battery connection terminal and the load; The battery connection terminal is electrically connected to the positive battery terminal and the negative battery terminal for receiving the battery output voltage and output current; The battery protection circuit is electrically connected to the battery connection terminal for controlling the conduction and disconnection of the circuit between the load and the battery to prevent over-discharge and over-current of the battery.

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