Switching circuit with short circuit protection function
By integrating the isolation switch module and the short-circuit protection module into the switching circuit, and utilizing the circuit design of optocoupler U1, transistor Q2, MOSFET Q3, MOSFET Q4 and transistor Q1, deep integration of signal isolation and power switch control is achieved, enabling rapid detection and interruption of short-circuit faults. This solves the problem of independent isolation and short-circuit protection functions in existing technologies, and improves system integration and response speed.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CETC XIAN NAVIGATION TECH CO LTD
- Filing Date
- 2025-09-15
- Publication Date
- 2026-08-04
AI Technical Summary
In existing switching circuits, the isolation function and short-circuit protection function are independent of each other, resulting in slow response speed, low system integration, and magnetic isolation relays have short service life and potential power supply safety hazards.
A switching circuit with short-circuit protection is adopted, integrating an isolating switch module and a short-circuit protection module. The circuit composed of optocoupler U1, transistor Q2, MOSFET Q3, MOSFET Q4 and transistor Q1 achieves deep integration of signal isolation and power switch control. The detection and control logic composed of transistors Q5, Q6 and Q7 quickly detects short-circuit faults and drives transistor Q1 to turn off power MOSFET Q4.
It achieves fast response and high integration of the switching circuit, has electrical isolation function, improves the reliability and safety of the switching circuit, and avoids the complexity and cost of additional protection circuits in traditional solutions.
Smart Images
Figure CN224596464U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of mobile overhead contact line technology, and in particular to a switching circuit with short-circuit protection function. Background Technology
[0002] In airborne environments, high-power loads are typically powered by DC 270V.
[0003] If you want to control the on / off state of this branch through low-voltage isolation, you generally use a series magnetic isolation relay, which can effectively isolate the low-voltage control terminal from the high-voltage power supply terminal. However, magnetic isolation relays have a limited lifespan, and their internal contacts are prone to sticking together in the later stages of use, posing a power supply safety hazard. Furthermore, if a short circuit fault occurs in the downstream stage or the power-on surge is too large, it may damage the relay and the upstream equipment.
[0004] Therefore, there is an urgent need to propose a switching circuit with short-circuit protection function. Utility Model Content
[0005] This application provides a switching circuit with short-circuit protection, which solves the technical problems of existing switching circuits where isolation and short-circuit protection functions are independent, response speed is slow, and system integration is low.
[0006] This utility model embodiment provides a switching circuit with short-circuit protection function, including an isolating switch module and a short-circuit protection module; the isolating switch module includes an optocoupler U1, a transistor Q2, a MOSFET Q3, a MOSFET Q4, and a transistor Q1; the anode and cathode of the optocoupler U1 are both input with constant voltages, the emitter of the optocoupler U1 is connected to the source of the MOSFET Q3, the gate of the MOSFET Q3 is input with a constant voltage, and the drain of the MOSFET Q3 is connected to the drain of the MOSFET Q4. The optocoupler U1 is connected to the base of transistor Q2, the collector of transistor Q2 is connected to the gate of MOSFET Q3, and the emitter of transistor Q2 is connected to the source of MOSFET Q3. A constant voltage is input to the gate of MOSFET Q4, the source of MOSFET Q4 is connected to the emitter of transistor Q1, the collector of transistor Q1 is connected to the gate of MOSFET Q4, and the emitter of transistor Q1 is connected to the output terminal of the short-circuit protection module.
[0007] In one possible implementation, the short-circuit protection module includes resistors R17 and R16, transistors Q5, Q6, and Q7; the base of transistor Q7 is connected to one end of resistor R17, the other end of resistor R17 is connected to the gate of MOSFET Q4, the emitter of transistor Q7 receives a constant voltage, the collector of transistor Q7 is connected to one end of resistor R16, and the other end of resistor R16 receives a sampling voltage; the base of transistor Q6 is connected between resistor R16 and transistor Q7, the emitter of transistor Q6 receives a constant voltage, the collector of transistor Q6 is connected to the base of transistor Q5; the emitter of transistor Q5 receives a sampling voltage, and the collector of transistor Q5 is connected to the base of transistor Q1.
[0008] In one possible implementation, the isolating switch module further includes resistors R1, R2, and R3; one end of resistor R1 receives a constant voltage input, and the other end of resistor R1 is connected to the base of transistor Q2; one end of resistor R2 receives a constant voltage input, and the other end of resistor R2 is connected to the gate of MOSFET Q3; one end of resistor R3 receives a constant voltage input, and the other end of resistor R3 is connected to the gate of MOSFET Q4.
[0009] In one possible implementation, the disconnect switch module further includes resistors R10 and R9, a Zener diode DZ1, and a Zener diode DZ3; one end of resistor R10 is connected to the base of transistor Q2, and the other end of resistor R10 is connected to the emitter of transistor Q2; the cathode of Zener diode DZ1 is connected between resistor R1 and optocoupler U1, and the anode of Zener diode DZ1 is connected to the base of transistor Q2; one end of resistor R9 is connected to the collector of transistor Q2, and the other end of resistor R9 is connected to the emitter of transistor Q2; the Zener diode DZ3 is connected in parallel across resistor R9.
[0010] In one possible implementation, the disconnect switch module further includes resistors R7 and R8 and a Zener diode DZ2; one end of resistor R7 is connected to the collector of transistor Q5, and the other end of resistor R7 is connected to the base of transistor Q1; one end of resistor R8 is connected to the collector of transistor Q1, and the other end of resistor R8 is connected to the emitter of transistor Q1; the Zener diode DZ2 is connected in parallel across resistor R8.
[0011] In one possible implementation, a sampling module is further included; the sampling module includes resistors R23, R24, R25, and R26, and a Zener diode DZ4; resistors R23, R24, R25, and R26 are connected in series, with one end of resistor R23 connected between resistors R1 and R2, and one end of resistor R26 connected to the drain of MOSFET Q3; the Zener diode DZ4 is connected in parallel across resistor R26; the sampling voltage is obtained from the common connection point of resistors R25 and R26.
[0012] In one possible implementation, the short-circuit protection module further includes resistors R22, R21, R20, R19, R14, R15, R11, R18, diode D1, and diode D2; one end of resistor R22 is connected to the base of transistor Q7, and the other end of resistor R22 is connected to one end of resistor R21, and the other end of resistor R21 is connected to the emitter of transistor Q7; one end of resistor R18 is connected to resistor R7, and the other end of resistor R18 is connected between resistors R22 and R21; the emitter of transistor Q1 is connected between resistors R18 and R22; one end of resistor R11 is connected between resistors R25 and R26. The other end of resistor R11 is connected to the base of transistor Q5; resistors R14 and R15 are connected in series between the collector of transistor Q5 and the base of transistor Q6; one end of resistor R20 is connected between resistors R14 and R15, and the other end of resistor R20 is connected between resistors R22 and R21; one end of resistor R19 is connected to the emitter of transistor Q6, and the other end of resistor R19 is connected between resistors R21 and R20; diodes D1 and D2 are connected in series, and the anode of diode D1 is connected between resistor R16 and transistor Q7, and the cathode of diode D2 is connected between resistors R15 and R20.
[0013] In one possible implementation, the isolating switch module further includes capacitors C1, C2, C3, C4, and C5; one end of capacitor C1 is connected between resistors R2 and R3, and the other end of capacitor C1 is connected to the emitter of transistor Q1; one end of capacitor C2 is connected between resistors R1 and R2, and the other end of capacitor C2 is connected between resistor R10 and Zener diode DZ3; capacitor C3 is connected in parallel across resistor R8; one end of capacitor C4 is connected to the source of MOSFET Q4, and the other end of capacitor C4 is connected to the gate of MOSFET Q4; capacitor C5 is connected in parallel across resistor R10.
[0014] In one possible implementation, a fuse F1 is also included, one end of which is input with a constant voltage, and the other end of which is connected between the capacitor C2 and the resistor R1.
[0015] In one possible implementation, the disconnect switch module further includes resistors R12 and R13, capacitors C6 and C7; one end of resistor R12 receives a constant voltage input, and the other end of resistor R12 is connected to the anode of optocoupler U1; resistor R13 is connected in parallel across resistor R12; one end of capacitor C7 is connected between the anode of optocoupler U1 and resistor R12, and the other end of capacitor C7 is connected to the cathode of optocoupler U1; one end of capacitor C6 is connected to the collector of optocoupler U1, and the other end of capacitor C6 is connected to the emitter of optocoupler U1.
[0016] One or more technical solutions provided in this application have at least the following technical effects: This embodiment of the invention employs a switching circuit with short-circuit protection, including an isolating switch module and a short-circuit protection module. The isolating switch module includes an optocoupler U1, a transistor Q2, a MOSFET Q3, a MOSFET Q4, and a transistor Q1. A constant voltage is input to both the anode and cathode of the optocoupler U1. The emitter of the optocoupler U1 is connected to the source of the MOSFET Q3, the gate of the MOSFET Q3 is input to a constant voltage, and the drain of the MOSFET Q3 is connected to the drain of the MOSFET Q4. The collector of the optocoupler U1 is connected to the base of the transistor Q2, the collector of the transistor Q2 is connected to the gate of the MOSFET Q3, and the emitter of the transistor Q2 is connected to the source of the MOSFET Q3. A constant voltage is input to the gate of the MOSFET Q4, the source of the MOSFET Q4 is connected to the emitter of the transistor Q1, the collector of the transistor Q1 is connected to the gate of the MOSFET Q4, and the emitter of the transistor Q1 is connected to the output terminal of the short-circuit protection module. This application achieves deep integration of signal isolation and power switch control by directly integrating the optocoupler U1 and the short-circuit protection module into the same circuit, avoiding the complexity and cost of additional protection circuits required in traditional solutions. Utilizing transistors Q5, Q6, and Q7 to construct the detection and control logic enables rapid detection of downstream short-circuit faults. By driving transistor Q1 to quickly turn off the power MOSFET Q4, the fault current path is cut off, thus achieving millisecond-level fast short-circuit protection. This solves the technical problems of existing switching circuits where isolation and short-circuit protection functions are independent, response speed is slow, and system integration is low. It results in a higher integration level for the switching circuit, along with fast response and electrical isolation capabilities, improving the reliability of the switching circuit. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments of this utility model or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 A circuit diagram of the disconnector module provided in an embodiment of this application; Figure 2 A circuit diagram of a short-circuit protection module provided in an embodiment of this application; Figure 3 A circuit diagram of the sampling module provided in an embodiment of this application. Detailed Implementation
[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of the present utility model. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present utility model.
[0020] In the description of the embodiments of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing the embodiments of this utility model and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In addition, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this utility model can be understood according to the specific circumstances.
[0021] This utility model embodiment provides a switching circuit with short-circuit protection function, such as Figure 1-3 As shown, the system includes an isolating switch module and a short-circuit protection module. The isolating switch module includes an optocoupler U1, a transistor Q2, a MOSFET Q3, a MOSFET Q4, and a transistor Q1. A constant voltage is input to both the anode and cathode of optocoupler U1. The emitter of optocoupler U1 is connected to the source of MOSFET Q3, the gate of MOSFET Q3 is input to a constant voltage, and the drain of MOSFET Q3 is connected to the drain of MOSFET Q4. The collector of optocoupler U1 is connected to the base of transistor Q2, the collector of transistor Q2 is connected to the gate of MOSFET Q3, and the emitter of transistor Q2 is connected to the source of MOSFET Q3. A constant voltage is input to the gate of MOSFET Q4, the source of MOSFET Q4 is connected to the emitter of transistor Q1, the collector of transistor Q1 is connected to the gate of MOSFET Q4, and the emitter of transistor Q1 is connected to the output terminal of the short-circuit protection module.
[0022] For example, when a voltage is applied to the base of transistor Q2, transistor Q2 is in the conducting state and MOSFET Q3 is in the cut-off state. When a 5VTTL high-level power-on signal is given to the diode terminal of optocoupler U1, the transistor after optocoupler U1 is turned on, thereby turning on MOSFET Q3 and turning off transistor Q2.
[0023] For example, when a 5VTTL high-level power-on signal is given to the diode terminal of optocoupler U1, MOSFET Q3 is turned on, allowing the sampling module to sample. The sampling voltage is input to the emitter of transistor Q5, enabling short-circuit protection. Specifically, during normal circuit operation, the base of transistor Q7 is high, making Q7 turn on, while transistor Q6 is off. The base of transistor Q5 is kept high through a pull-up resistor. Since Q5 is a PNP transistor, it is also turned off. At this time, transistor Q1 is off, while MOSFET Q4 is turned on, and the circuit operates normally. MOSFET Q4 also has reverse connection protection. When a short-circuit fault occurs in the subsequent stage, transistor Q7 is off, transistor Q6 is on, the base of transistor Q5 is pulled low, making Q5 turn on, and when the base of transistor Q1 is high, transistor Q1 is on, while MOSFET Q4 is off, thus achieving short-circuit protection.
[0024] In the embodiments of this application, such as Figure 1-2 As shown, the short-circuit protection module includes resistors R17 and R16, transistors Q5, Q6, and Q7. The base of transistor Q7 is connected to one end of resistor R17, and the other end of resistor R17 is connected to the gate of MOSFET Q4. A constant voltage is input to the emitter of transistor Q7, and the collector of transistor Q7 is connected to one end of resistor R16, with a sampling voltage input to the other end of resistor R16. The base of transistor Q6 is connected between resistor R16 and transistor Q7, and a constant voltage is input to the emitter of transistor Q6. The collector of transistor Q6 is connected to the base of transistor Q5. The sampling voltage is input to the emitter of transistor Q5, and the collector of transistor Q5 is connected to the base of transistor Q1.
[0025] In the embodiments of this application, such as Figure 1-2 As shown, the disconnecting switch module also includes resistors R1, R2, and R3; one end of resistor R1 is input with a constant voltage, and the other end of resistor R1 is connected to the base of transistor Q2; one end of resistor R2 is input with a constant voltage, and the other end of resistor R2 is connected to the gate of MOSFET Q3; one end of resistor R3 is input with a constant voltage, and the other end of resistor R3 is connected to the gate of MOSFET Q4.
[0026] For example, the disconnecting switch module also includes resistors R4, R5, and R6; one end of resistor R4 is connected to resistor R3, and the other end of resistor R4 is connected to the gate of MOSFET Q4; one end of resistor R5 is connected to resistor R1, and the other end of resistor R5 is connected between optocoupler U1 and Zener diode DZ1; one end of resistor R6 is connected to resistor R2, and the other end of resistor R6 is connected to the gate of MOSFET Q3.
[0027] In the embodiments of this application, such as Figure 1-2 As shown, the disconnect switch module also includes resistors R10 and R9, Zener diodes DZ1 and DZ3; one end of resistor R10 is connected to the base of transistor Q2, and the other end of resistor R10 is connected to the emitter of transistor Q2; the cathode of Zener diode DZ1 is connected between resistor R1 and optocoupler U1, and the anode of Zener diode DZ1 is connected to the base of transistor Q2; one end of resistor R9 is connected to the collector of transistor Q2, and the other end of resistor R9 is connected to the emitter of transistor Q2; Zener diode DZ3 is connected in parallel across resistor R9.
[0028] In the embodiments of this application, such as Figure 1-2 As shown, the disconnect switch module also includes resistors R7 and R8 and a Zener diode DZ2; one end of resistor R7 is connected to the collector of transistor Q5, and the other end of resistor R7 is connected to the base of transistor Q1; one end of resistor R8 is connected to the collector of transistor Q1, and the other end of resistor R8 is connected to the emitter of transistor Q1; the Zener diode DZ2 is connected in parallel across resistor R8.
[0029] In the embodiments of this application, such as Figure 1-3 As shown, it also includes a sampling module; the sampling module includes resistors R23, R24, R25, and R26, and a Zener diode DZ4; resistors R23, R24, R25, and R26 are connected in series, with one end of resistor R23 connected between resistors R1 and R2, and one end of resistor R26 connected to the drain of MOSFET Q3; the Zener diode DZ4 is connected in parallel across resistor R26; the sampling voltage is sampled between resistors R25 and R26.
[0030] In the embodiments of this application, such as Figure 1-2As shown, the short-circuit protection module also includes resistors R22, R21, R20, R19, R14, R15, R11, R18, diode D1, and diode D2; one end of resistor R22 is connected to the base of transistor Q7, the other end of resistor R22 is connected to one end of resistor R21, and the other end of resistor R21 is connected to the emitter of transistor Q7; one end of resistor R18 is connected to resistor R7, and the other end of resistor R18 is connected between resistors R22 and R21; the emitter of transistor Q1 is connected between resistors R18 and R22; one end of resistor R11 is connected to resistors R25 and R18. Between resistors R11 and R20, the other end of resistor R11 is connected to the base of transistor Q5; resistors R14 and R15 are connected in series between the collector and collector of transistor Q5 and the base of transistor Q6; one end of resistor R20 is connected between resistors R14 and R15, and the other end of resistor R20 is connected between resistors R22 and R21; one end of resistor R19 is connected to the emitter of transistor Q6, and the other end of resistor R19 is connected between resistors R21 and R20; diodes D1 and D2 are connected in series, with the anode of diode D1 connected between resistor R16 and transistor Q7, and the cathode of diode D2 connected between resistors R15 and R20.
[0031] In the embodiments of this application, such as Figure 1-2 As shown, the disconnecting switch module also includes capacitors C1, C2, C3, C4, and C5; one end of capacitor C1 is connected between resistors R2 and R3, and the other end of capacitor C1 is connected to the emitter of transistor Q1; one end of capacitor C2 is connected between resistors R1 and R2, and the other end of capacitor C2 is connected between resistor R10 and Zener diode DZ3; capacitor C3 is connected in parallel across resistor R8; one end of capacitor C4 is connected to the source of MOSFET Q4, and the other end of capacitor C4 is connected to the gate of MOSFET Q4; capacitor C5 is connected in parallel across resistor R10.
[0032] In the embodiments of this application, such as Figure 1-2 As shown, it also includes a fuse F1, one end of which is input with a constant voltage, and the other end of which is connected between a capacitor C2 and a resistor R1.
[0033] In the embodiments of this application, such as Figure 1-2As shown, the disconnecting switch module also includes resistors R12 and R13, capacitors C6 and C7; one end of resistor R12 is input with a constant voltage, and the other end of resistor R12 is connected to the anode of optocoupler U1; resistor R13 is connected in parallel across resistor R12; one end of capacitor C7 is connected between the anode of optocoupler U1 and resistor R12, and the other end of capacitor C7 is connected to the cathode of optocoupler U1; one end of capacitor C6 is connected to the collector of optocoupler U1, and the other end of capacitor C6 is connected to the emitter of optocoupler U1.
[0034] For example, capacitor C7 is connected in parallel across the LED of optocoupler U1 to accelerate the response speed of optocoupler or suppress interference.
[0035] The various embodiments in this specification are described in a progressive manner. For the same or similar parts between the various embodiments, please refer to each other. Each embodiment focuses on describing the differences from other embodiments.
[0036] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of this application.
Claims
1. A switching circuit with short-circuit protection function, characterized in that, Includes disconnector modules and short-circuit protection modules; The isolating switch module includes an optocoupler U1, a transistor Q2, a MOSFET Q3, a MOSFET Q4, and a transistor Q1; The anode and cathode of the optocoupler U1 are both input with a constant voltage. The emitter of the optocoupler U1 is connected to the source of the MOS transistor Q3. The gate of the MOS transistor Q3 is input with a constant voltage. The drain of the MOS transistor Q3 is connected to the drain of the MOS transistor Q4. The collector of the optocoupler U1 is connected to the base of the transistor Q2, the collector of the transistor Q2 is connected to the gate of the MOS transistor Q3, and the emitter of the transistor Q2 is connected to the source of the MOS transistor Q3. The gate of the MOS transistor Q4 is supplied with a constant voltage. The source of the MOS transistor Q4 is connected to the emitter of the transistor Q1. The collector of the transistor Q1 is connected to the gate of the MOS transistor Q4. The emitter of the transistor Q1 is connected to the output terminal of the short-circuit protection module.
2. The switching circuit with short-circuit protection function according to claim 1, characterized in that, The short-circuit protection module includes resistor R17, resistor R16, transistor Q5, transistor Q6, and transistor Q7; The base of transistor Q7 is connected to one end of resistor R17, the other end of resistor R17 is connected to the gate of MOSFET Q4, the emitter of transistor Q7 is input with a constant voltage, the collector of transistor Q7 is connected to one end of resistor R16, and the other end of resistor R16 is input with a sampling voltage. The base of transistor Q6 is connected between resistor R16 and transistor Q7. The emitter of transistor Q6 receives a constant voltage. The collector of transistor Q6 is connected to the base of transistor Q5. The emitter of transistor Q5 is input with a sampling voltage, and the collector of transistor Q5 is connected to the base of transistor Q1.
3. The switching circuit with short-circuit protection function according to claim 2, characterized in that, The disconnect switch module also includes resistors R1, R2, and R3; A constant voltage is input to one end of the resistor R1, and the other end of the resistor R1 is connected to the base of the transistor Q2; A constant voltage is input to one end of the resistor R2, and the other end of the resistor R2 is connected to the gate of the MOS transistor Q3; A constant voltage is input to one end of the resistor R3, and the other end of the resistor R3 is connected to the gate of the MOS transistor Q4.
4. The switching circuit with short-circuit protection function according to claim 3, characterized in that, The disconnect switch module also includes resistor R10, resistor R9, Zener diode DZ1, and Zener diode DZ3; One end of the resistor R10 is connected to the base of the transistor Q2, and the other end of the resistor R10 is connected to the emitter of the transistor Q2. The cathode of the Zener diode DZ1 is connected between the resistor R1 and the optocoupler U1, and the anode of the Zener diode DZ1 is connected to the base of the transistor Q2. One end of the resistor R9 is connected to the collector of the transistor Q2, and the other end of the resistor R9 is connected to the emitter of the transistor Q2. The Zener diode DZ3 is connected in parallel across the resistor R9.
5. The switching circuit with short-circuit protection function according to claim 2, characterized in that, The isolating switch module also includes resistors R7 and R8 and Zener diode DZ2; One end of the resistor R7 is connected to the collector of the transistor Q5, and the other end of the resistor R7 is connected to the base of the transistor Q1. One end of the resistor R8 is connected to the collector of the transistor Q1, and the other end of the resistor R8 is connected to the emitter of the transistor Q1. The Zener diode DZ2 is connected in parallel across the resistor R8.
6. The switching circuit with short-circuit protection function according to claim 3, characterized in that, It also includes a sampling module; The sampling module includes resistors R23, R24, R25, and R26, and a Zener diode DZ4. The resistors R23, R24, R25 and R26 are connected in series, with one end of resistor R23 connected between resistors R1 and R2, and one end of resistor R26 connected to the drain of MOSFET Q3. The Zener diode DZ4 is connected in parallel across the resistor R26; The sampling voltage is obtained from the common connection point of resistors R25 and R26.
7. The switching circuit with short-circuit protection function according to claim 5, characterized in that, The short-circuit protection module also includes resistors R22, R21, R20, R19, R14, R15, R11, R18, diode D1, and diode D2. One end of resistor R22 is connected to the base of transistor Q7, the other end of resistor R22 is connected to one end of resistor R21, and the other end of resistor R21 is connected to the emitter of transistor Q7. One end of resistor R18 is connected to resistor R7, and the other end of resistor R18 is connected between resistor R22 and resistor R21; The emitter of the transistor Q1 is connected between the resistor R18 and the resistor R22; One end of resistor R11 is connected between resistor R25 and resistor R26, and the other end of resistor R11 is connected to the base of transistor Q5. The resistors R14 and R15 are connected in series between the collector of transistor Q5 and the base of transistor Q6; One end of resistor R20 is connected between resistor R14 and resistor R15, and the other end of resistor R20 is connected between resistor R22 and resistor R21; One end of the resistor R19 is connected to the emitter of the transistor Q6, and the other end of the resistor R19 is connected between the resistor R21 and the resistor R20; The diodes D1 and D2 are connected in series, with the anode of the diode D1 connected between the resistor R16 and the transistor Q7, and the cathode of the diode D2 connected between the resistor R15 and the resistor R20.
8. The switching circuit with short-circuit protection function according to claim 4, characterized in that, The disconnector module also includes capacitors C1, C2, C3, C4, and C5; One end of the capacitor C1 is connected between the resistor R2 and the resistor R3, and the other end of the capacitor C1 is connected to the emitter of the transistor Q1. One end of the capacitor C2 is connected between the resistor R1 and the resistor R2, and the other end of the capacitor C2 is connected between the resistor R10 and the Zener diode DZ3; The capacitor C3 is connected in parallel across the resistor R8; One end of the capacitor C4 is connected to the source of the MOSFET Q4, and the other end of the capacitor C4 is connected to the gate of the MOSFET Q4. The capacitor C5 is connected in parallel across the resistor R10.
9. The switching circuit with short-circuit protection function according to claim 8, characterized in that, It also includes a fuse F1, one end of which is input with a constant voltage, and the other end of which is connected between the capacitor C2 and the resistor R1.
10. The switching circuit with short-circuit protection function according to claim 1, characterized in that, The disconnector switch module also includes resistor R12, resistor R13, capacitor C6, and capacitor C7; A constant voltage is input to one end of the resistor R12, and the other end of the resistor R12 is connected to the anode of the optocoupler U1. The resistor R13 is connected in parallel across the two ends of the resistor R12; One end of the capacitor C7 is connected between the anode of the optocoupler U1 and the resistor R12, and the other end of the capacitor C7 is connected to the cathode of the optocoupler U1. One end of the capacitor C6 is connected to the collector of the optocoupler U1, and the other end of the capacitor C6 is connected to the emitter of the optocoupler U1.