Protection circuit, electrical system and vehicle
By designing protection circuits for vehicle electrical systems, including anti-reverse protection modules, short-circuit protection modules and quick shutdown control modules, short-circuit problems caused by circuit complexity and precision are solved, and the effect of rapid shutdown and effective protection of the power supply network is achieved.
Patent Information
- Application Number
- CN202421928108.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-08
- Publication Date
- 2025-06-24
- Estimated Expiration
- 2034-08-08
AI Technical Summary
The complexity and precision of circuits in vehicle electrical systems increase, resulting in wrong power connections or abnormal current flow, which may cause short circuits. How to improve the safety of the circuit has become an urgent problem.
A protection circuit is designed, including an anti-reverse protection module, a short-circuit protection module and a quick shutdown control module. Through the combination of these modules, the power input and output terminals are protected to ensure that the power output can be quickly turned off when a short circuit occurs.
It effectively reduces the time required to shut down the power output during short circuit, more effectively protects the power network, and reduces the safety hazards caused by the circuit and the possibility of component damage during short circuit.
Smart Images
Figure CN223024078U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of circuit protection, and particularly to a protection circuit, an electrical system, and a vehicle. Background Art
[0002] With the continuous improvement of the electrification and intelligence levels of vehicles, the complexity and precision of circuits in vehicle electrical systems have also increased accordingly. Any minor mistake or oversight may lead to incorrect power connections or short - circuit phenomena caused by abnormal current flow. Therefore, how to improve the safety of circuits has become an urgent problem to be solved. Summary of the Utility Model
[0003] Embodiments of this application provide a protection circuit, an electrical system, and a vehicle to solve at least one of the above - mentioned technical problems.
[0004] The protection circuit of the embodiments of this application, the protection circuit includes an anti - reverse - connection protection module, a short - circuit protection module, and a fast - turn - off control module. The first end of the anti - reverse - connection protection module is used to connect to the power input terminal, the second end of the anti - reverse - connection protection module is used to connect to the power output terminal, the third end of the anti - reverse - connection protection module is connected to the first end of the short - circuit protection module, the second end of the short - circuit protection module is used to connect to the power output terminal, the third end of the short - circuit protection module is connected to the first end of the fast - turn - off control module, and the second end of the fast - turn - off control module is used to connect to the power output terminal.
[0005] In some embodiments, the anti - reverse - connection protection module includes a first transistor. The drain of the first transistor is used to connect to the power input terminal, the source of the first transistor is used to connect to the power output terminal, and the gate of the first transistor is connected to the first end of the short - circuit protection module.
[0006] In some embodiments, the anti - reverse - connection protection module further includes a self - resetting fuse, and the self - resetting fuse is arranged between the power input terminal and the drain of the first transistor.
[0007] In some embodiments, the anti - reverse - connection protection module further includes a first capacitor, a first resistor, and a first diode. The first end of the first capacitor, the first end of the first resistor, and the cathode of the first diode are all connected to the source of the first transistor, and the second end of the first capacitor, the second end of the first resistor, and the anode of the first diode are all connected to the gate of the first transistor.
[0008] In some embodiments, the reverse connection protection module further includes a second capacitor and a second resistor. The first ends of the second capacitor and the second resistor are both connected to the gate of the first transistor, and the second ends of the second capacitor and the second resistor are grounded.
[0009] In some embodiments, the short - circuit protection module includes a second transistor. The collector of the second transistor is connected to the third terminal of the reverse connection protection module. The emitter of the second transistor is used to be connected to the power output terminal, and the base of the second transistor is connected to the first terminal of the fast - turn - off control module.
[0010] In some embodiments, the short - circuit protection module further includes a third resistor and a fourth resistor. The first end of the third resistor is connected to the emitter of the second transistor, and the second end of the third resistor is connected to the base of the second transistor and the first end of the fourth resistor.
[0011] In some embodiments, the fast - turn - off control module includes a second diode and a fifth resistor. The positive electrode of the second diode is connected to the third terminal of the short - circuit protection module, the negative electrode of the second diode is connected to the first end of the fifth resistor, and the second end of the fifth resistor is used to be connected to the power output terminal.
[0012] In some embodiments, the protection circuit further includes a short - circuit protection control module and a short - circuit state latching module. The first terminal of the short - circuit protection control module is connected to the fourth terminal of the short - circuit protection module. The second terminal of the short - circuit protection control module is connected to the output terminal of the short - circuit state latching module. The third terminal of the short - circuit protection control module is grounded. The first input terminal of the short - circuit state latching module is used to be connected to the voltage division of the power input terminal, and the second input terminal of the short - circuit state latching module is used to be connected to the voltage division of the power output terminal.
[0013] In some embodiments, the short - circuit protection control module includes a third transistor. The collector of the third transistor is connected to the fourth terminal of the short - circuit protection module. The base of the third transistor is connected to the output terminal of the short - circuit state latching module, and the emitter of the third transistor is grounded.
[0014] In some embodiments, the short - circuit protection control module further includes a sixth resistor and a seventh resistor. The first end of the sixth resistor is connected to the output terminal of the short - circuit state latching module. The second end of the sixth resistor is connected to the base of the third transistor and the first end of the seventh resistor. The second end of the seventh resistor is connected to the emitter of the third transistor.
[0015] In some embodiments, the short - circuit state latching module includes a comparator which has an output latching function. The first input terminal of the comparator is used for being connected in a voltage - dividing manner to the power input terminal, the second input terminal of the comparator is used for being connected in a voltage - dividing manner to the power output terminal, and the output terminal of the comparator is connected to the short - circuit protection control module.
[0016] In some embodiments, the short - circuit state latching module further includes an eighth resistor. The first end of the eighth resistor is connected to the voltage input terminal of the comparator, and the second end of the eighth resistor is connected to the output terminal of the comparator.
[0017] In some embodiments, the short - circuit state latching module further includes a ninth resistor, a tenth resistor, an eleventh resistor, and a twelfth resistor. The first input terminal of the comparator is grounded successively through the ninth resistor and the tenth resistor, and the second input terminal of the comparator is grounded successively through the eleventh resistor and the twelfth resistor.
[0018] In some embodiments, the short - circuit state latching module further includes a thirteenth resistor and a fourteenth resistor. The first end of the thirteenth resistor is connected between the ninth resistor and the tenth resistor, and the second end of the thirteenth resistor is used for being connected to the power input terminal. The first end of the fourteenth resistor is connected between the eleventh resistor and the twelfth resistor, and the second end of the fourteenth resistor is used for being connected to the power output terminal.
[0019] The electrical system according to the embodiment of the present application includes the protection circuit according to any of the above - mentioned embodiments.
[0020] The vehicle according to the embodiment of the present application includes the electrical system according to the above - mentioned embodiment.
[0021] In the protection circuit, electrical system, and vehicle according to the embodiment of the present application, the first end of the reverse - connection protection module is used for being connected to the power input terminal, the third end of the reverse - connection protection module is connected to the first end of the short - circuit protection module, the third end of the short - circuit protection module is connected to the first end of the fast - turn - off control module, and the second end of the fast - turn - off control module is used for being connected to the power output terminal. Thus, when a short - circuit occurs, the fast - turn - off control module can quickly turn off the power output, reduce the turn - off time required to turn off the power output, and more effectively protect the power network.
[0022] The additional aspects and advantages of the present application will be partly given in the following description, partly will become obvious from the following description, or will be understood through the practice of the present application. Description of the Drawings
[0023] To more clearly illustrate the technical solutions in the embodiments of the present application or the related art, the following will briefly introduce the drawings required for use in the description of the embodiments or the related art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings. Among them:
[0024] Figure 1 is a schematic structural diagram of a protection circuit in some embodiments of the present application;
[0025] Figure 2 is a schematic block diagram of a protection circuit in some embodiments of the present application;
[0026] Figure 3 is a schematic block diagram of an electrical system in some embodiments of the present application;
[0027] Figure 4 is a schematic structural diagram of a vehicle in some embodiments of the present application.
[0028] Description of reference numerals:
[0029] Protection circuit 100, reverse connection protection module 10, short-circuit protection module 20, fast turn-off control module 30, short-circuit protection control module 40, short-circuit state latching module 50, power input terminal 60, power output terminal 70, first transistor Q1, second transistor Q2, third transistor Q3, self-resetting fuse F, first capacitor C1, second capacitor C2, third capacitor C3, fourth capacitor C4, first resistor R1, second resistor R2, third resistor R3, fourth resistor R4, fifth resistor R5, sixth resistor R6, seventh resistor R7, eighth resistor R8, ninth resistor R9, tenth resistor R10, eleventh resistor R11, twelfth resistor R12, thirteenth resistor R13, fourteenth resistor R14, first diode D1, second diode D2, comparator U, electrical system 200, vehicle 300. Specific embodiments
[0030] The following will describe in detail the embodiments of the present application. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals always represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present application and should not be construed as a limitation of the present application.
[0031] Please refer to Figure 1 and Figure 2, an embodiment of the present application provides a protection circuit 100. The protection circuit 100 includes an anti-reverse connection protection module 10, a short-circuit protection module 20, and a fast turn-off control module 30. The first end of the anti-reverse connection protection module 10 is used to connect to the power input terminal 60, the second end of the anti-reverse connection protection module 10 is used to connect to the power output terminal 70, and the third end of the anti-reverse connection protection module 10 is connected to the first end of the short-circuit protection module 20. The second end of the short-circuit protection module 20 is used to connect to the power output terminal 70, and the third end of the short-circuit protection module 20 is connected to the first end of the fast turn-off control module 30. The second end of the fast turn-off control module 30 is used to connect to the power output terminal 70.
[0032] In the protection circuit 100 according to the embodiment of the present application, the first end of the anti-reverse connection protection module 10 is used to connect to the power input terminal 60, the third end of the anti-reverse connection protection module 10 is connected to the first end of the short-circuit protection module 20, the third end of the short-circuit protection module 20 is connected to the first end of the fast turn-off control module 30, and the second end of the fast turn-off control module 30 is used to connect to the power output terminal 70. Thus, when a short circuit occurs, the fast turn-off control module 30 can quickly turn off the power output, reduce the turn-off time required to turn off the power output, and more effectively protect the power network.
[0033] Specifically, under normal circumstances, the anti-reverse connection protection module 10 is turned on, and the current flows from the first end of the anti-reverse connection protection module 10 to the second end of the anti-reverse connection protection module 10, that is, from the power input terminal 60 to the power output terminal 70, and the power output terminal 70 can normally supply power to the subsequent load. When a short circuit occurs in the power supply, the power output terminal 70 is at a low voltage, the fast turn-off control module 30 is turned on, and the fast turn-off control module 30 can quickly pull down the voltage at the third end of the short-circuit protection module 20, so that the short-circuit protection module 20 is turned on, thereby turning off the anti-reverse connection protection module 10, avoiding damage to the subsequent load, and protecting the power network.
[0034] Please refer to Figure 1 , in some embodiments, the anti-reverse connection protection module 10 includes a first transistor Q1. The drain of the first transistor Q1 is used to connect to the power input terminal 60, the source of the first transistor Q1 is used to connect to the power output terminal 70, and the gate of the first transistor Q1 is connected to the first end of the short-circuit protection module 20.
[0035] Specifically, the drain of the first transistor Q1 can be used as the first end of the anti-reverse connection protection module 10, the source of the first transistor Q1 can be used as the second end of the anti-reverse connection protection module 10, and the gate of the first transistor Q1 can be used as the third end of the anti-reverse connection protection module 10.
[0036] The first transistor Q1 can be a PMOS transistor, and the first transistor Q1 includes a body diode. Under normal circumstances, the body diode is in a conducting state, and current flows from the positive pole to the negative pole of the body diode, that is, from the power input terminal 60 to the power output terminal 70. When the power supply is reversely connected (i.e., the power input terminal 60 and the power output terminal 70 are connected reversely), the current cannot flow from the positive pole to the negative pole of the body diode, and the body diode is in a cut-off state. In this way, the reverse connection protection module 10 can block the current through the first transistor Q1, so as to protect the power network when the power supply is reversely connected.
[0037] Please refer to Figure 1 , in some embodiments, the reverse connection protection module 10 further includes a self-resetting fuse F. The self-resetting fuse F is arranged between the power input terminal 60 and the drain of the first transistor Q1.
[0038] Specifically, the self-resetting fuse F can be made of a specially treated polymeric resin and has the characteristics of melting and changing shape at high temperature and restoring its original shape when cooled. When a short circuit occurs in the power supply, the self-resetting fuse F automatically becomes a high-resistance state due to the current exceeding the set threshold, thereby cutting off the current and preventing the components in the circuit from being damaged due to overcurrent. When the fault is eliminated, the current returns to the normal level, and the self-resetting fuse F automatically returns to the low-resistance state to continue protecting the circuit without replacement.
[0039] Please refer to Figure 1 , in some embodiments, the reverse connection protection module 10 further includes a first capacitor C1, a first resistor R1, and a first diode D1. The first end of the first capacitor C1, the first end of the first resistor R1, and the negative pole of the first diode D1 are all connected to the source of the first transistor Q1, and the second end of the first capacitor C1, the second end of the first resistor R1, and the positive pole of the first diode D1 are all connected to the gate of the first transistor Q1.
[0040] Specifically, the first capacitor C1, the first resistor R1, and the first diode D1 are connected in parallel between the source and the gate of the first transistor Q1. The first capacitor C1 can stabilize the output voltage of the first transistor Q1 and reduce the output voltage change caused by the power supply voltage fluctuation. The first resistor R1 can divide the voltage to limit the current magnitude. The first diode D1 can be a Zener diode. A Zener diode is a diode that can also conduct under reverse bias voltage and has the characteristic of stable voltage. When the reverse voltage increases to a certain extent (i.e., reaches the Zener voltage), the reverse current will increase sharply, but at this time the voltage of the Zener diode remains basically unchanged. In the protection circuit 100, the first diode D1 can play a role in stabilizing the voltage between the gate and the source of the first transistor Q1.
[0041] Please refer to Figure 1, in some embodiments, the reverse connection protection module 10 further includes a second capacitor C2 and a second resistor R2. The first end of the second capacitor C2 and the first end of the second resistor R2 are both connected to the gate of the first transistor Q1, and the second end of the second capacitor C2 and the second end of the second resistor R2 are grounded.
[0042] Specifically, the second capacitor C2 and the second resistor R2 are arranged in parallel. When the first transistor Q1 is in the working state, there needs to be a certain voltage difference (usually called the gate-source voltage) between the source and the gate, and this voltage difference is a necessary condition for the normal operation of the first transistor Q1. The second resistor R2 can be used to adjust this voltage difference to meet the operating requirements of the first transistor Q1. By changing the resistance value of the second resistor R2, the gate voltage can be adjusted, thereby controlling the on and off states of the first transistor Q1. The second capacitor C2 helps to stabilize the operating state of the protection circuit 100. By adjusting the capacitance value and type of the capacitor, the performance and stability of the protection circuit 100 can be optimized.
[0043] Please refer to Figure 1 , in some embodiments, the short-circuit protection module 20 includes a second transistor Q2. The collector of the second transistor Q2 is connected to the third end of the reverse connection protection module 10, the emitter of the second transistor Q2 is used to connect to the power output terminal 70, and the base of the second transistor Q2 is connected to the first end of the fast turn-off control module 30.
[0044] Specifically, the collector of the second transistor Q2 can be used as the first end of the short-circuit protection module 20, the emitter of the second transistor Q2 can be used as the second end of the short-circuit protection module 20, and the base of the second transistor Q2 can be used as the third end of the short-circuit protection module 20. The second transistor Q2 can be a bipolar PNP transistor. The collector of the second transistor Q2 is connected to the gate of the aforementioned first transistor Q1.
[0045] Please refer to Figure 1 , in some embodiments, the short-circuit protection module 20 further includes a third resistor R3 and a fourth resistor R4. The first end of the third resistor R3 is connected to the emitter of the second transistor Q2, and the second end of the third resistor R3 is connected to the base of the second transistor Q2 and the first end of the fourth resistor R4.
[0046] Specifically, the third resistor R3 is arranged between the emitter and the base of the second transistor Q2. The third resistor R3 can stabilize the static operating point of the second transistor Q2, thereby making the performance of the protection circuit 100 more stable. One end of the fourth resistor R4 is connected to the base of the second transistor Q2, which can prevent the current flowing into the base from being too large and burning out the second transistor Q2. The second end of the fourth resistor R4 can be used as the fourth end of the short-circuit protection module 20.
[0047] Please refer toFigure 1 In some embodiments, the fast turn-off control module 30 includes a second diode D2 and a fifth resistor R5. The positive electrode of the second diode D2 is connected to the third terminal of the short-circuit protection module 20, and the negative electrode of the second diode D2 is connected to the first terminal of the fifth resistor R5. The second terminal of the fifth resistor R5 is used to connect to the power output terminal 70.
[0048] Specifically, the positive electrode of the second diode D2 can be used as the first terminal of the fast turn-off control module 30, and the second terminal of the fifth resistor R5 can be used as the second terminal of the fast turn-off control module 30.
[0049] The positive electrode of the second diode D2 is connected to the base of the aforementioned second transistor Q2. The second diode D2 can be a Schottky diode, and its forward conduction voltage drop is lower than that of a common diode, which can reduce the power consumption of the protection circuit 100. However, the reverse voltage withstand capacity of a Schottky diode is usually lower than that of a common diode. If the reverse voltage exceeds its rated reverse voltage withstand value, the Schottky diode may be broken down and damaged. At this time, the fifth resistor R5 can play a role in limiting the current to prevent the reverse voltage from bringing too large a current to damage the second diode D2. Among them, the fast turn-off control module 30 may further include a third capacitor C3. The first terminal of the third capacitor C3 is connected to the positive electrode of the second diode D2, and the second terminal of the third capacitor C3 is grounded. The third capacitor C3 can play a role in energy storage.
[0050] Under normal circumstances, the voltage value of the power input terminal 60 is basically equal to the voltage value of the power output terminal 70, and the voltages of the positive and negative electrodes of the second diode D2 are equal and cannot conduct. At the moment when the power supply is short-circuited, the voltage value of the power input terminal 60 basically remains unchanged, while the voltage value of the power output terminal 70 will be pulled down to ground. At this time, the voltage of the negative electrode of the second diode D2 will be pulled down to ground by the voltage of the power output terminal 70 (the voltage state of the power output terminal 70 is converted into the control signal input of the fast turn-off control module 30), and the positive electrode voltage is greater than or equal to 0V, and the second diode D2 conducts, making the base of the second transistor Q2 at a low level. At this time, the second transistor Q2 is in the conducting state. When the second transistor Q2 is in the conducting state, the gate-source voltage of the first transistor Q1 is made consistent, which does not meet the conduction condition of the first transistor Q1, so the first transistor Q1 is in the off state, thereby turning off the power output and effectively protecting the power network.
[0051] In the related art, the input voltage is compared and calculated through a comparator, and then the short-circuit protection circuit is controlled to turn off the power output. If the calculation time of the comparator is too long during this process, it will cause an increase in the time used to turn off the power output, which will further damage the circuit and components, and at the same time increase the safety hazards of high temperature and sparks generated by the circuit during short-circuit.
[0052] In the embodiment of the present application, at the moment when the power supply has a short circuit, the voltage of the base of the second transistor Q2 is quickly pulled down through the second diode D2, so that Q2 is turned on, and thus Q1 is turned off. The power supply output can be quickly turned off, reducing the turn-off time required to turn off the power supply output, more effectively protecting the power supply network, reducing the potential safety hazards generated by the circuit during a short circuit, and also reducing the possibility of component damage.
[0053] Please refer to Figure 1 , the protection circuit 100 may further include a fourth capacitor C4. The first end of the fourth capacitor C4 is connected to the source of the first transistor Q1, and the second end of the fourth capacitor C4 is grounded. The fourth capacitor C4 can store energy and is used to improve the stability and anti-interference performance of the protection circuit 100.
[0054] Please refer to Figure 1 and Figure 2 , in some embodiments, the protection circuit 100 further includes a short-circuit protection control module 40 and a short-circuit state latching module 50. The first end of the short-circuit protection control module 40 is connected to the fourth end of the short-circuit protection module 20, the second end of the short-circuit protection control module 40 is connected to the output end of the short-circuit state latching module 50, and the third end of the short-circuit protection control module 40 is grounded. The first input end of the short-circuit state latching module 50 is used for voltage division connection with the power supply input end 60, and the second input end of the short-circuit state latching module 50 is used for voltage division connection with the power supply output end 70.
[0055] Specifically, the short-circuit state latching module 50 can control the conduction and turn-off of the short-circuit protection control module 40, and further, the short-circuit protection control module 40 can control the conduction and turn-off of the short-circuit protection module 20.
[0056] Under normal circumstances, the voltage division of the power supply input end 60 and the power supply output end 70 causes the short-circuit state latching module 50 to output a low level, the short-circuit protection control module 40 is turned off, and the short-circuit protection module 20 is turned off. Thus, the reverse connection protection module 10 is turned on, and the power supply output end 70 can normally supply power to the subsequent load. When the power supply has a short circuit, the voltage division of the power supply input end 60 and the power supply output end 70 causes the short-circuit state latching module 50 to output a high level, the short-circuit protection control module 40 is turned on, and the short-circuit protection module 20 is turned on. Thus, the reverse connection protection module 10 is turned off, avoiding damage to the subsequent load and protecting the power supply network.
[0057] Please refer to Figure 1 , in some embodiments, the short-circuit protection control module 40 includes a third transistor Q3. The collector of the third transistor Q3 is connected to the fourth end of the short-circuit protection module 20, the base of the third transistor Q3 is connected to the output end of the short-circuit state latching module 50, and the emitter of the third transistor Q3 is grounded.
[0058] Specifically, the collector of the third transistor Q3 can serve as the first terminal of the short - circuit protection control module 40, and the emitter of the third transistor Q3 can serve as the third terminal of the short - circuit protection control module 40. The third transistor Q3 can be a bipolar NPN - type transistor. The collector of the third transistor Q3 is connected to the aforementioned fourth resistor R4.
[0059] Please refer to Figure 1 , in some embodiments, the short - circuit protection control module 40 further includes a sixth resistor R6 and a seventh resistor R7. The first terminal of the sixth resistor R6 is connected to the output terminal of the short - circuit state latching module 50. The second terminal of the sixth resistor R6 is connected to the base of the third transistor Q3 and the first terminal of the seventh resistor R7. The second terminal of the seventh resistor R7 is connected to the emitter of the third transistor Q3.
[0060] Specifically, the first terminal of the sixth resistor R6 can serve as the second terminal of the short - circuit protection control module 40. The sixth resistor R6 can limit the current flowing in from the short - circuit state latching module 50 to prevent excessive current from damaging the third transistor Q3. The seventh resistor R7 is disposed between the base and the emitter of the third transistor Q3, which helps to stabilize the voltage between the base and the emitter of the third transistor Q3, and further makes the operating point of the third transistor Q3 more stable.
[0061] Please refer to Figure 1 , in some embodiments, the short - circuit state latching module 50 includes a comparator U. The comparator U has an output latching function. The first input terminal of the comparator U is used for voltage division connection with the power input terminal 60, the second input terminal of the comparator U is used for voltage division connection with the power output terminal 70, and the output terminal of the comparator U is connected to the short - circuit protection control module 40.
[0062] Specifically, the first input terminal of the comparator U can serve as the first input terminal of the short - circuit state latching module 50, the second input terminal of the comparator U can serve as the second input terminal of the short - circuit state latching module 50, and the output terminal of the comparator U can serve as the output terminal of the short - circuit state latching module 50. The output latching function of the comparator U means that when the output of its output terminal is at a high level, it can maintain the high - level output until it is reset, and after being reset, the output of the output terminal is at a low level.
[0063] When the comparator U works, it will compare and calculate the voltage values of the first input terminal and the second input terminal. The first input terminal can be the non-inverting input terminal, and the second input terminal can be the inverting input terminal. Under normal circumstances, the voltage of the first input terminal is lower than that of the second input terminal, and the output terminal of the comparator U outputs a low level, making the base of the third transistor Q3 also at a low level. Since the emitter of the third transistor Q3 is connected to the ground and the emitter voltage is also at a low level, the condition for the third transistor Q3 to conduct is not satisfied. The third transistor Q3 is in the off state, the second transistor Q2 is off, and the first transistor Q1 is on, and the power output terminal 70 can normally supply power to the subsequent load. When a short circuit occurs in the power supply, the voltage value of the first input terminal is higher than that of the second input terminal, and the output terminal of the comparator U outputs a high level, making the base of the third transistor Q3 also at a high level. When the base of the third transistor Q3 is at a high level and the emitter is at a low level, the third transistor Q3 is in the conducting state and pulls down the base voltage of the second transistor Q2. The second transistor Q2 conducts, and the first transistor Q1 turns off, thereby turning off the power output and effectively protecting the power network.
[0064] In the related art, a comparator with an output latching function is not used in the protection circuit. After a short circuit occurs in the power supply, the protection circuit will perform an automatic protection measure of turning off the power supply to make the power supply return to normal. When the power supply is turned on again, a cycle of "power short circuit, turn off the power output, power supply returns to normal, power supply is turned on, power short circuit" will occur, causing damage to the electronic components in the circuit.
[0065] In the embodiment of the present application, a comparator U with an output latching function is adopted. Since the comparator U has an output latching function, when the output at its output terminal is at a high level, it will maintain the output high level. At this time, the third transistor Q3 can be continuously made to conduct, the second transistor Q2 conducts, and the first transistor Q1 turns off, maintaining the power output off. It is not until the comparator U is reset that the power output can return to normal. Thus, the above cycle process can be avoided, and the power network can be better protected.
[0066] Please refer to Figure 1 , in some embodiments, the short-circuit state latching module 50 further includes an eighth resistor R8. The first end of the eighth resistor R8 is connected to the voltage input terminal of the comparator U, and the second end of the eighth resistor R8 is connected to the output terminal of the comparator U.
[0067] Specifically, the eighth resistor R8 can serve as a pull-up resistor to ensure the normal operation of the comparator U and output a predetermined level. The voltage input terminal of the comparator U can be used to connect to the power input terminal 60. In normal conditions and when a short circuit occurs in the power supply, the voltage input terminal of the comparator U is connected to the power input terminal 60, and a positive voltage is applied, enabling the comparator U to operate normally; when the power supply is reverse-connected, the voltage input terminal of the comparator U is connected to the power output terminal 70, and a reverse voltage is applied, causing it to stop working. The comparator U may further include a ground terminal for grounding.
[0068] Please refer to Figure 1 , in some embodiments, the short-circuit state latching module 50 further includes a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, and a twelfth resistor R12. The first input terminal of the comparator U is grounded sequentially through the ninth resistor R9 and the tenth resistor R10, and the second input terminal of the comparator U is grounded sequentially through the eleventh resistor R11 and the twelfth resistor R12.
[0069] Specifically, the ninth resistor R9 and the twelfth resistor R12 may have the same first resistance value, and the tenth resistor R10 and the eleventh resistor R11 may have the same second resistance value. Among them, the first resistance value is different from the second resistance value. By setting different resistance values, different proportions of voltage division can be achieved, so that the voltage values applied to the first input terminal and the second input terminal of the comparator U are different. Under normal circumstances, after the power input terminal 60 is voltage-divided and then connected to the first input terminal, and the power output terminal 70 is voltage-divided and then connected to the second input terminal, the voltage of the first input terminal of the comparator U is lower than that of the second input terminal, and the output terminal of the comparator U outputs a low level. When a short circuit occurs in the power supply, after the power input terminal 60 is voltage-divided and then connected to the first input terminal, and the power output terminal 70 is voltage-divided and then connected to the second input terminal, the voltage of the first input terminal of the comparator U is higher than that of the second input terminal, and the output terminal of the comparator U outputs a high level.
[0070] Please refer to Figure 1 , in some embodiments, the short-circuit state latching module 50 further includes a thirteenth resistor R13 and a fourteenth resistor R14. The first end of the thirteenth resistor R13 is connected between the ninth resistor R9 and the tenth resistor R10, and the second end of the thirteenth resistor R13 is used to connect to the power input terminal 60. The first end of the fourteenth resistor R14 is connected between the eleventh resistor R11 and the twelfth resistor R12, and the second end of the fourteenth resistor R14 is used to connect to the power output terminal 70.
[0071] Specifically, the thirteenth resistor R13 and the fourteenth resistor R14 can play a role in current limiting, and can prevent the currents generated by the power input terminal 60 and the power output terminal 70 from being too large and affecting the comparator U.
[0072] In summary, the working process of the protection circuit 100 according to the embodiment of the present application is as follows: Under normal circumstances, the voltage at the first input terminal of the comparator U is lower than the voltage at the second input terminal. The output terminal of the comparator U outputs a low level, the third transistor Q3 is turned off, the second transistor Q2 is turned off, and the first transistor Q1 is turned on. The power output terminal 70 can normally supply power to the subsequent load. When the power supply is reversely connected, the body diode of the first transistor Q1 can block the reverse connection loop and avoid damaging the power supply network. When a short circuit occurs, on the one hand, the voltage at the base of the second transistor Q2 is quickly pulled down through the second diode D2, causing Q2 to turn on, and thus Q1 to turn off, so that the power output can be quickly turned off, reducing the turn-off time required to turn off the power output; on the other hand, the voltage at the first input terminal of the comparator U is higher than the voltage at the second input terminal. The output terminal of the comparator U outputs a high level until the comparator U is reset. The third transistor Q3 is turned on, the second transistor Q2 is turned on, and the first transistor Q1 is turned off, thereby turning off the power output and effectively protecting the power supply network; on the third hand, in the case where the first two aspects both fail, the self-resetting fuse F can automatically blow, further increasing the protection measure and more effectively protecting the power supply network.
[0073] Please refer to Figure 3 , the embodiment of the present application further provides an electrical system 200. The electrical system 200 includes the protection circuit 100 according to any of the above embodiments. The protection circuit 100 can be provided in each link of the electrical system 200.
[0074] Please refer to Figure 4 , the embodiment of the present application further provides a vehicle 300. The vehicle 300 includes the above electrical system 200.
[0075] In the protection circuit 100, electrical system 200, and vehicle 300 according to the embodiments of the present application, the first end of the reverse connection protection module 10 is used to connect to the power input terminal 60, the third end of the reverse connection protection module 10 is connected to the first end of the short circuit protection module 20, the third end of the short circuit protection module 20 is connected to the first end of the fast turn-off control module 30, and the second end of the fast turn-off control module 30 is used to connect to the power output terminal 70. In this way, when a short circuit occurs, the fast turn-off control module 30 can quickly turn off the power output, reduce the turn-off time required to turn off the power output, and more effectively protect the power supply network.
[0076] In the description of the present application, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. are based on the orientation or positional relationships shown in the drawings. These are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the present application. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more features. In the description of the present application, "a plurality" means two or more, unless otherwise specifically defined.
[0077] In the description of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "mounted", "connected" and "coupled" shall be construed broadly. For example, it may be a fixed connection, a detachable connection or an integral connection; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.
[0078] In the present application, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through additional features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely means that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "below" and "beneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely means that the horizontal height of the first feature is lower than that of the second feature.
[0079] The foregoing disclosure provides many different embodiments or examples for implementing different structures of the present application. To simplify the disclosure of the present application, the components and settings of specific examples are described above. Of course, they are merely examples and are not intended to limit the present application. In addition, the present application may repeat reference numerals and / or reference letters in different examples. This repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present application provides examples of various specific processes and materials, but those of ordinary skill in the art may be aware of the application of other processes and / or the use of other materials.
[0080] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "examples", "specific examples", "some examples", etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.
[0081] Although the embodiments of the present application have been shown and described above, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present application. The scope of the present application is defined by the claims and their equivalents.
Claims
1. A protection circuit, characterized in that: The protection circuit includes an anti-reverse connection protection module, a short circuit protection module and a fast shutdown control module. The first end of the anti-reverse connection protection module is used to connect to the power input end, the second end of the anti-reverse connection protection module is used to connect to the power output end, the third end of the anti-reverse connection protection module is connected to the first end of the short circuit protection module, the second end of the short circuit protection module is used to connect to the power output end, the third end of the short circuit protection module is connected to the first end of the fast shutdown control module, and the second end of the fast shutdown control module is used to connect to the power output end.
2. The protection circuit according to claim 1, characterized in that: The anti-reverse connection protection module includes a first transistor, a drain of the first transistor is used to connect to the power input end, a source of the first transistor is used to connect to the power output end, and a gate of the first transistor is connected to the first end of the short circuit protection module.
3. The protection circuit according to claim 2, characterized in that: The anti-reverse connection protection module further includes a resettable fuse, and the resettable fuse is arranged between the power input terminal and the drain of the first transistor.
4. The protection circuit according to claim 2, characterized in that: The anti-reverse connection protection module also includes a first capacitor, a first resistor and a first diode, the first end of the first capacitor, the first end of the first resistor and the cathode of the first diode are all connected to the source of the first transistor, and the second end of the first capacitor, the second end of the first resistor and the anode of the first diode are all connected to the gate of the first transistor.
5. The protection circuit according to claim 2, characterized in that: The anti-reverse connection protection module also includes a second capacitor and a second resistor, wherein a first end of the second capacitor and a first end of the second resistor are both connected to the gate of the first transistor, and a second end of the second capacitor and a second end of the second resistor are grounded.
6. The protection circuit according to claim 1, characterized in that: The short-circuit protection module includes a second transistor, the collector of the second transistor is connected to the third end of the anti-reverse connection protection module, the emitter of the second transistor is used to be connected to the power supply output end, and the base of the second transistor is connected to the first end of the fast shutdown control module.
7. The protection circuit according to claim 6, characterized in that: The short circuit protection module further includes a third resistor and a fourth resistor, wherein a first end of the third resistor is connected to the emitter of the second transistor, and a second end of the third resistor is connected to the base of the second transistor and a first end of the fourth resistor.
8. The protection circuit according to claim 1, characterized in that: The fast shutdown control module includes a second diode and a fifth resistor, the anode of the second diode is connected to the third end of the short-circuit protection module, the cathode of the second diode is connected to the first end of the fifth resistor, and the second end of the fifth resistor is used to be connected to the power supply output end.
9. The protection circuit according to claim 1, characterized in that: The protection circuit also includes a short-circuit protection control module and a short-circuit state latch module, wherein the first end of the short-circuit protection control module is connected to the fourth end of the short-circuit protection module, the second end of the short-circuit protection control module is connected to the output end of the short-circuit state latch module, the third end of the short-circuit protection control module is grounded, the first input end of the short-circuit state latch module is used to be connected to the divided voltage of the power supply input end, and the second input end of the short-circuit state latch module is used to be connected to the divided voltage of the power supply output end.
10. The protection circuit according to claim 9, characterized in that: The short-circuit protection control module comprises a third transistor, the collector of the third transistor is connected to the fourth end of the short-circuit protection module, the base of the third transistor is connected to the output end of the short-circuit state latch module, and the emitter of the third transistor is grounded.
11. The protection circuit according to claim 10, characterized in that: The short-circuit protection control module also includes a sixth resistor and a seventh resistor, the first end of the sixth resistor is connected to the output end of the short-circuit state latch module, the second end of the sixth resistor is connected to the base of the third transistor and the first end of the seventh resistor, and the second end of the seventh resistor is connected to the emitter of the third transistor.
12. The protection circuit according to claim 9, characterized in that: The short-circuit state latch module includes a comparator, which has an output latch function. The first input end of the comparator is used to be connected to the divided voltage of the power input end, the second input end of the comparator is used to be connected to the divided voltage of the power output end, and the output end of the comparator is connected to the short-circuit protection control module.
13. The protection circuit according to claim 12, characterized in that: The short-circuit state latch module further includes an eighth resistor, a first end of the eighth resistor is connected to the voltage input end of the comparator, and a second end of the eighth resistor is connected to the output end of the comparator.
14. The protection circuit according to claim 12, characterized in that: The short-circuit state latch module also includes a ninth resistor, a tenth resistor, an eleventh resistor and a twelfth resistor. The first input end of the comparator is grounded through the ninth resistor and the tenth resistor in sequence, and the second input end of the comparator is grounded through the eleventh resistor and the twelfth resistor in sequence.
15. The protection circuit according to claim 14, characterized in that: The short-circuit state latch module also includes a thirteenth resistor and a fourteenth resistor, the first end of the thirteenth resistor is connected between the ninth resistor and the tenth resistor, the second end of the thirteenth resistor is used to connect to the power input terminal, the first end of the fourteenth resistor is connected between the eleventh resistor and the twelfth resistor, and the second end of the fourteenth resistor is used to connect to the power output terminal.
16. An electrical system, characterized in that: A protection circuit comprising any one of claims 1 to 15.
17. A vehicle, characterized in that: An electrical system comprising the invention as claimed in claim 16.