Switching power supply short circuit protection circuit
By combining a power supply module, a power regulation module, a feedback module, a short-circuit protection module, and a timing module, the problem of frequent power outages in switching power supplies under frequent short-circuit conditions is solved, stable short-circuit protection is achieved, and the service life of the equipment is extended.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHENZHEN CHUXINZHIZHI TECHNOLOGY CO LTD
- Filing Date
- 2025-05-23
- Publication Date
- 2026-04-24
AI Technical Summary
Existing switching power supplies frequently shut down and restart under frequent short-circuit conditions, resulting in a reduced service life.
It employs a combination of a power supply module, a power regulation module, a feedback module, a short-circuit protection module, a status detection module, and a timing module. By detecting potential changes and controlling timing, it avoids frequent starts of the power regulation module and achieves stable short-circuit protection.
It improves the lifespan of the switching power supply, avoids frequent power outages and restarts, and extends the service life of the equipment.
Smart Images
Figure CN224164624U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of switching power supply technology, specifically a short-circuit protection circuit for switching power supplies. Background Technology
[0002] A switching power supply is a device that uses modern power electronics technology to achieve efficient conversion of electrical energy through high-frequency switching operations. It converts the input voltage (AC or DC) into a stable DC output voltage or current required by the user. To improve the safety and intelligence of switching power supplies, short-circuit detection is performed and short-circuit protection is implemented when a short circuit occurs. After the short circuit disappears, power supply is automatically restored. However, when short circuits occur frequently, the switching power supply will frequently shut down and restart, reducing its service life. Therefore, improvements are needed. Utility Model Content
[0003] This utility model provides a short-circuit protection circuit for a switching power supply to solve the problems mentioned in the background art.
[0004] To achieve the above objectives, this utility model provides the following technical solution:
[0005] A short-circuit protection circuit for a switching power supply includes: a power module, a power regulation module, an output module, a feedback module, a short-circuit protection module, a status detection module, and a timing module.
[0006] The power module is used to connect to DC power.
[0007] The power regulation module, connected to the power supply module and the feedback module, is used to receive DC power and the feedback signal output by the feedback module, and to perform power regulation and isolation transformation processing on the DC power to output the first power.
[0008] The output module, connected to the power regulation module, is used to rectify and filter the first electrical energy and then output it.
[0009] The feedback module, connected to the output module, is used to perform voltage division sampling on the electrical energy output by the output module, compare it with a set voltage threshold, and output a feedback signal.
[0010] The short-circuit protection module is connected to the power supply module, the short-circuit protection module and the power regulation module. It is used to detect the potential change of the feedback signal of the input power regulation module and control the power regulation module to stop receiving DC power when a short circuit occurs.
[0011] The status detection module, connected to the short-circuit protection module and the feedback module, is used to receive feedback signals and output control signals when the power regulation module stops receiving DC power.
[0012] The timing module, connected to the power supply module, status detection module, and short-circuit protection module, is used to set the timing time and receive DC power. Upon receiving a control signal, it starts timing operation and controls the short-circuit protection module to control the power regulation module to stop receiving DC power.
[0013] As a further embodiment of this utility model: the power supply module includes a power interface and a first capacitor; the power regulation module includes a second capacitor, a second resistor, a first diode, a first transformer, a first power transistor, and a driving device; the output module includes a second diode, a third capacitor, a first inductor, a fourth capacitor, and an output port;
[0014] Preferably, the first end of the power interface is connected to one end of the first capacitor, one end of the second resistor, the power supply terminal of the driving device, and the first end of the primary side of the first transformer. It is also connected to the other end of the second resistor and the cathode of the first diode through the second capacitor. The anode of the first diode is connected to the second end of the primary side of the first transformer and the drain of the first power transistor. The source of the first power transistor is connected to the ground terminal of the driving device, the other end of the first capacitor, the second end of the power interface, and the ground terminal. The gate of the first power transistor is connected to the driving terminal of the driving device. The first end of the secondary side of the first transformer is connected to the anode of the second diode. The cathode of the second diode is connected to the first end of the first inductor and is connected to the second end of the secondary side of the first transformer, one end of the fourth capacitor, and one end of the output port through the third capacitor. The second end of the first inductor is connected to the other end of the fourth capacitor and the other end of the output port.
[0015] As a further embodiment of this utility model: the feedback module includes a fourth resistor, a third resistor, a fifth capacitor, a fifth resistor, a sixth resistor, a first reference power supply, a sixth capacitor, a seventh resistor, a first operational amplifier, an eighth resistor, and a first optocoupler;
[0016] Preferably, one end of the fourth resistor is connected to the second end of the first inductor and is connected in sequence to the other end of the fourth resistor, the non-inverting input of the first operational amplifier, one end of the fifth resistor, and one end of the sixth resistor through the third resistor and the fifth capacitor. The other end of the fifth resistor is connected to the other end of the sixth resistor, the second end of the first optocoupler, and ground. The inverting input of the first operational amplifier is connected to the first reference power supply and is connected in sequence to the output terminal of the first operational amplifier and one end of the eighth resistor through the sixth capacitor and the seventh resistor. The other end of the eighth resistor is connected to the first end of the first optocoupler. The third end of the first optocoupler is connected to the feedback terminal of the driving device. The fourth end of the first optocoupler is connected to the source of the first power transistor.
[0017] As a further improvement of this utility model: the short-circuit protection module includes a first resistor, a first adjustable Zener diode, a tenth resistor, a ninth resistor, and a third diode;
[0018] Preferably, the cathode of the first adjustable Zener diode is connected to the power supply terminal of the drive device through the first resistor, the anode of the first adjustable Zener diode is connected to the ground terminal of the drive device, the control terminal of the first adjustable Zener diode is connected to the timing module and one end of the ninth resistor and grounded through the tenth resistor, the other end of the ninth resistor is connected to the cathode of the third diode, and the anode of the third diode is connected to the feedback terminal of the drive device.
[0019] As a further embodiment of this utility model: the state detection module includes a first inverter, a fourth diode, a fifth diode, and a first logic chip;
[0020] Preferably, the input terminal of the first inverter is connected to the cathode of the first adjustable Zener diode, the output terminal of the first inverter is connected to the B terminal of the first logic chip, the A terminal of the first logic chip is connected to the cathodes of the fourth diode and the fifth diode, the anode of the fifth diode is connected to the Y terminal of the first logic chip and the timing module, and the anode of the fourth diode is connected to the non-inverting input of the first operational amplifier.
[0021] As a further embodiment of this utility model: the timing module includes a second power transistor, a seventh diode, an eleventh resistor, a seventh capacitor, a first timer, an eighth capacitor, a twelfth resistor, a first switching transistor, and a sixth diode;
[0022] Preferably, the drain of the second power transistor is connected to the first terminal of the power interface, the source of the second power transistor is connected to the cathode of the seventh diode, the collector of the first switching transistor, the fourth and eighth terminals of the first timer, and is connected to the anode of the seventh diode, one end of the seventh capacitor, the sixth and second terminals of the first timer through the eleventh resistor, the fifth terminal of the first timer is connected to the first terminal of the first timer, the other end of the seventh capacitor, one end of the twelfth resistor and ground through the eighth capacitor, the emitter of the first switching transistor is connected to the anode of the sixth diode and the other end of the twelfth resistor, the cathode of the sixth diode is connected to the control terminal of the first adjustable Zener diode, and the gate of the second power transistor is connected to the Y terminal of the first logic chip.
[0023] Compared with the prior art, the beneficial effects of this utility model are as follows: The short-circuit protection circuit of this utility model for switching power supply can use a power regulation module in conjunction with a feedback module to perform power regulation and isolation transformation of the electrical energy input to the power module, thereby providing voltage regulation for the output module. The short-circuit protection module detects the output short-circuit state based on the potential change between the power regulation module and the feedback module. When a short circuit occurs, it controls the power regulation module to stop working and, in conjunction with the status detection module, controls the timing module to perform timed operation and maintain the short-circuit protection operation of the short-circuit protection module for a period of time. After the timed operation ends, the short-circuit protection module performs short-circuit detection again, avoiding frequent start-up of the power regulation module when a short circuit occurs, thus improving the service life of the switching power supply. Attached Figure Description
[0024] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments of this utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0025] Figure 1 This is a schematic block diagram of a short-circuit protection circuit for a switching power supply, provided as an example of this utility model.
[0026] Figure 2 A circuit diagram of a short-circuit protection circuit for a switching power supply provided as an example of this utility model.
[0027] Figure 3 The connection circuit diagram of the timing module provided for this utility model embodiment. Detailed Implementation
[0028] 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 embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0029] In one embodiment, see Figure 1 A short-circuit protection circuit for a switching power supply includes: a power module 1, a power regulation module 2, an output module 3, a feedback module 4, a short-circuit protection module 5, a status detection module 6, and a timing module 7.
[0030] Specifically, power module 1 is used to connect to DC power;
[0031] The power regulation module 2 is connected to the power supply module 1 and the feedback module 4. It is used to receive DC power and the feedback signal output by the feedback module 4, and to perform power regulation and isolation transformation processing on the DC power to output the first power.
[0032] Output module 3, connected to power regulation module 2, is used to rectify and filter the first electrical energy and output it.
[0033] Feedback module 4, connected to output module 3, is used to perform voltage division sampling on the electrical energy output by output module 3, compare it with a set voltage threshold, and output a feedback signal.
[0034] The short-circuit protection module 5 is connected to the power supply module 1, the short-circuit protection module 5 and the power regulation module 2. It is used to detect the potential change of the feedback signal of the input power regulation module 2 and control the power regulation module 2 to stop receiving DC power when a short circuit occurs.
[0035] The status detection module 6 is connected to the short-circuit protection module 5 and the feedback module 4. It is used to receive feedback signals and output control signals when the power regulation module 2 stops receiving DC power.
[0036] The timing module 7 is connected to the power supply module 1, the status detection module 6, and the short-circuit protection module 5. It is used to set the timing time and receive DC power. When a control signal is received, it starts timing operation and controls the short-circuit protection module 5 to control the power regulation module 2 to stop receiving DC power.
[0037] In a specific embodiment, the power supply module 1 can be a power supply circuit composed of power throttling and capacitors, and can be connected to DC power; the power regulation module 2 can be a power regulation circuit composed of drive states, diodes, comparators, field-effect transistors, etc., which can absorb peak voltages and perform power regulation and isolation transformation processing on the input power according to the feedback signal provided by the feedback module 4; the output module 3 can be an output circuit composed of diodes, capacitors, output ports, etc., which performs rectification and filtering processing; the feedback module 4 can be a feedback circuit composed of resistors, operational amplifiers, optocouplers, etc., which can perform voltage division sampling of the power of the output module 3, set a voltage threshold, compare the sampled signal with the input signal, and provide feedback to the power regulation module 2. The feedback signal, the voltage threshold of which is the required output regulated voltage value; the short-circuit protection module 5 can be a short-circuit protection circuit composed of an adjustable Zener diode, a resistor and a diode, which can judge the short circuit based on the potential state at the connection between the detection feedback module 4 and the power regulation module 2, and control the power regulation module 2 to cut off the power when a short circuit occurs; the state detection module 6 can be a state detection circuit composed of an inverter, a logic chip and a diode, which can detect the working state of the feedback module 4 and the short-circuit protection module 5, and control the timing module 7 to work when a short circuit occurs; the timing module 7 can be a timing circuit composed of a field-effect transistor, a timer, a capacitor, a transistor, etc., which can set the timing time and provide a high-level signal within the timing time to control the short-circuit protection module 5 to maintain the short-circuit protection operation.
[0038] In another embodiment, please refer to Figure 1 , Figure 2 and Figure 3The power module 1 includes a power interface and a first capacitor C1; the power regulation module 2 includes a second capacitor C2, a second resistor R2, a first diode D1, a first transformer B1, a first power transistor Q1 and a driving device; the output module 3 includes a second diode D2, a third capacitor C3, a first inductor L1, a fourth capacitor C4 and an output port.
[0039] Specifically, the first end of the power interface is connected to one end of the first capacitor C1, one end of the second resistor R2, the power supply terminal of the drive device, and the first end of the primary side of the first transformer B1. It is also connected to the other end of the second resistor R2 and the cathode of the first diode D1 through the second capacitor C2. The anode of the first diode D1 is connected to the second end of the primary side of the first transformer B1 and the drain of the first power transistor Q1. The source of the first power transistor Q1 is connected to the ground terminal of the drive device, the other end of the first capacitor C1, the second end of the power interface, and the ground terminal. The gate of the first power transistor Q1 is connected to the drive terminal of the drive device. The first end of the secondary side of the first transformer B1 is connected to the anode of the second diode D2. The cathode of the second diode D2 is connected to the first end of the first inductor L1. It is also connected to the second end of the secondary side of the first transformer B1, one end of the fourth capacitor C4, and one end of the output port through the third capacitor C3. The second end of the first inductor L1 is connected to the other end of the fourth capacitor C4 and the other end of the output port.
[0040] In a specific embodiment, the driving device can be a UC3842 driving chip; the first power transistor Q1 can be an N-channel MOSFET.
[0041] Furthermore, the feedback module 4 includes a fourth resistor R4, a third resistor R3, a fifth capacitor C5, a fifth resistor R5, a sixth resistor R6, a first reference power supply VREF, a sixth capacitor C6, a seventh resistor R7, a first operational amplifier OP1, an eighth resistor R8, and a first optocoupler U2.
[0042] Specifically, one end of the fourth resistor R4 is connected to the second end of the first inductor L1, and is connected in sequence through the third resistor R3 and the fifth capacitor C5 to the other end of the fourth resistor R4, the non-inverting input of the first operational amplifier OP1, one end of the fifth resistor R5, and one end of the sixth resistor R6. The other end of the fifth resistor R5 is connected to the other end of the sixth resistor R6, the second end of the first optocoupler U2, and ground. The inverting input of the first operational amplifier OP1 is connected to the first reference power supply VREF, and is connected in sequence through the sixth capacitor C6 and the seventh resistor R7 to the output terminal of the first operational amplifier OP1 and one end of the eighth resistor R8. The other end of the eighth resistor R8 is connected to the first end of the first optocoupler U2. The third end of the first optocoupler U2 is connected to the feedback terminal of the driving device. The fourth end of the first optocoupler U2 is connected to the source of the first power transistor Q1.
[0043] In a specific embodiment, the third resistor R3, the fourth resistor R4, the fifth resistor R5, the sixth resistor R6, and the fifth capacitor C5 are used for voltage division sampling; the first operational amplifier OP1 can be an OP07 operational amplifier; and the first optocoupler U2 can be a PC817 optocoupler.
[0044] Furthermore, the short-circuit protection module 5 includes a first resistor R1, a first adjustable Zener diode U1, a tenth resistor R11, a ninth resistor R9, and a third diode D3;
[0045] Specifically, the cathode of the first adjustable Zener diode U1 is connected to the power supply terminal of the drive device through the first resistor R1, the anode of the first adjustable Zener diode U1 is connected to the ground terminal of the drive device, the control terminal of the first adjustable Zener diode U1 is connected to the timing module 7 and one end of the ninth resistor R9 and grounded through the tenth resistor R11, the other end of the ninth resistor R9 is connected to the cathode of the third diode D3, and the anode of the third diode D3 is connected to the feedback terminal of the drive device.
[0046] In a specific embodiment, the first adjustable Zener diode U1 can be a TL431 chip.
[0047] Furthermore, the state detection module 6 includes a first inverter INV1, a fourth diode D4, a fifth diode D5, and a first logic chip J1;
[0048] Specifically, the input terminal of the first inverter INV1 is connected to the cathode of the first adjustable Zener diode U1, the output terminal of the first inverter INV1 is connected to the B terminal of the first logic chip J1, the A terminal of the first logic chip J1 is connected to the cathodes of the fourth diode D4 and the fifth diode D5, the anode of the fifth diode D5 is connected to the Y terminal of the first logic chip J1 and the timing module 7, and the anode of the fourth diode D4 is connected to the non-inverting input of the first operational amplifier OP1.
[0049] In a specific embodiment, the first inverter INV1 can be a NOT gate chip; the first logic chip J1 can be an AND gate chip, which works with the fourth diode D4 and the fifth diode D5 to perform high-level self-locking.
[0050] Furthermore, the timing module 7 includes a second power transistor Q2, a seventh diode D7, an eleventh resistor R11, a seventh capacitor C7, a first timer IC1, an eighth capacitor C8, a twelfth resistor R12, a first switching transistor V1, and a sixth diode D6;
[0051] Specifically, the drain of the second power transistor Q2 is connected to the first terminal of the power interface, the source of the second power transistor Q2 is connected to the cathode of the seventh diode D7, the collector of the first switching transistor V1, the fourth and eighth terminals of the first timer IC1, and is connected to the anode of the seventh diode D7, one end of the seventh capacitor C7, the sixth and second terminals of the first timer IC1 through the eleventh resistor R11, the fifth terminal of the first timer IC1 is connected to the first terminal of the first timer IC1, the other end of the seventh capacitor C7, one end of the twelfth resistor R12 and the ground terminal through the eighth capacitor C8, the emitter of the first switching transistor V1 is connected to the anode of the sixth diode D6 and the other end of the twelfth resistor R12, the cathode of the sixth diode D6 is connected to the control terminal of the first adjustable Zener diode U1, and the gate of the second power transistor Q2 is connected to the Y terminal of the first logic chip J1.
[0052] In a specific embodiment, the first timer IC1 can be an NE555 chip; the first switch V1 can be an NPN transistor; and the second power transistor Q2 can be an N-channel MOSFET.
[0053] In this embodiment of a short-circuit protection circuit for a switching power supply, DC power is input through the power interface. A first capacitor C1 filters the power. The driving device is powered on and drives the first power transistor Q1 to conduct. A first transformer B1 transforms the voltage. A second diode D2, a third capacitor C3, a first inductor L1, and a fourth capacitor C4 perform rectification and filtering to output the first power. A fourth resistor R4, a third resistor R3, a fifth capacitor C5, a fifth resistor R5, and a sixth resistor R6 sample the voltage of the first resistor R1. A first operational amplifier OP1, in conjunction with a sixth capacitor C6, a seventh resistor R7, an eighth resistor R8, a first reference power supply VREF, and a first optocoupler U2, performs voltage comparison and provides a feedback signal to the feedback terminal of the driving device. The driving device then adjusts the conduction state of the first power transistor Q1 to regulate the first power output. When a short circuit occurs at the port, the first optocoupler U2 is cut off, the feedback terminal potential of the drive device rises, and when it exceeds the reference of the first adjustable Zener diode U1, it triggers the first adjustable Zener diode U1 to conduct, pulling down the power supply voltage of the drive device, and the drive device stops working. At the same time, the first inverter INV1 outputs a high level, the first logic chip J1, together with the fourth diode D4 and the fifth diode D5, outputs a high level and triggers the second power transistor Q2 to conduct. The first timer IC1, together with the seventh diode D7, the eleventh resistor R11, the seventh capacitor C7 and the eighth capacitor C8, starts timing and triggers the first switching transistor V1 to conduct, maintaining the conduction of the first adjustable Zener diode U1, maintaining the short circuit protection operation, and after the timing ends, the short circuit protection module 5 performs short circuit detection and protection again. If no short circuit occurs, the drive device is powered back on.
[0054] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.
[0055] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.
Claims
1. A short-circuit protection circuit for a switching power supply, characterized in that, The short-circuit protection circuit of this switching power supply includes: a power module, a power regulation module, an output module, a feedback module, a short-circuit protection module, a status detection module, and a timing module; The power module is used to connect to DC power. The power regulation module is connected to the power supply module and the feedback module. It is used to receive DC power and the feedback signal output by the feedback module, and to perform power regulation and isolation transformation processing on the DC power to output the first power. The output module is connected to the power regulation module and is used to rectify and filter the first electrical energy and output it. The feedback module is connected to the output module and is used to perform voltage division sampling on the electrical energy output by the output module, compare it with a set voltage threshold, and output a feedback signal. The short-circuit protection module is connected to the power supply module, the short-circuit protection module and the power regulation module. It is used to detect the potential change of the feedback signal of the input power regulation module and control the power regulation module to stop receiving DC power when a short circuit occurs. The status detection module is connected to the short-circuit protection module and the feedback module, and is used to receive feedback signals and output control signals when the power regulation module stops receiving DC power. The timing module is connected to the power supply module, the status detection module, and the short-circuit protection module. It is used to set the timing time and receive DC power. When a control signal is received, it starts timing operation and controls the short-circuit protection module to control the power regulation module to stop receiving DC power.
2. The short-circuit protection circuit for a switching power supply according to claim 1, characterized in that, The power module includes a power interface and a first capacitor; the power regulation module includes a second capacitor, a second resistor, a first diode, a first transformer, a first power transistor, and a driving device; the output module includes a second diode, a third capacitor, a first inductor, a fourth capacitor, and an output port. The first end of the power interface is connected to one end of the first capacitor, one end of the second resistor, the power supply terminal of the driving device, and the first end of the primary side of the first transformer. It is also connected to the other end of the second resistor and the cathode of the first diode through the second capacitor. The anode of the first diode is connected to the second end of the primary side of the first transformer and the drain of the first power transistor. The source of the first power transistor is connected to the ground terminal of the driving device, the other end of the first capacitor, the second end of the power interface, and the ground terminal. The gate of the first power transistor is connected to the driving terminal of the driving device. The first end of the secondary side of the first transformer is connected to the anode of the second diode. The cathode of the second diode is connected to the first end of the first inductor and is connected to the second end of the secondary side of the first transformer, one end of the fourth capacitor, and one end of the output port through the third capacitor. The second end of the first inductor is connected to the other end of the fourth capacitor and the other end of the output port.
3. A short-circuit protection circuit for a switching power supply according to claim 2, characterized in that, The feedback module includes a fourth resistor, a third resistor, a fifth capacitor, a fifth resistor, a sixth resistor, a first reference power supply, a sixth capacitor, a seventh resistor, a first operational amplifier, an eighth resistor, and a first optocoupler; One end of the fourth resistor is connected to the second end of the first inductor and is connected in sequence through the third resistor and the fifth capacitor to the other end of the fourth resistor, the non-inverting input of the first operational amplifier, one end of the fifth resistor, and one end of the sixth resistor. The other end of the fifth resistor is connected to the other end of the sixth resistor, the second end of the first optocoupler, and ground. The inverting input of the first operational amplifier is connected to the first reference power supply and is connected in sequence through the sixth capacitor and the seventh resistor to the output terminal of the first operational amplifier and one end of the eighth resistor. The other end of the eighth resistor is connected to the first end of the first optocoupler. The third end of the first optocoupler is connected to the feedback terminal of the driving device. The fourth end of the first optocoupler is connected to the source of the first power transistor.
4. A short-circuit protection circuit for a switching power supply according to claim 3, characterized in that, The short-circuit protection module includes a first resistor, a first adjustable Zener diode, a tenth resistor, a ninth resistor, and a third diode; The cathode of the first adjustable Zener diode is connected to the power supply terminal of the drive device through the first resistor, the anode of the first adjustable Zener diode is connected to the ground terminal of the drive device, the control terminal of the first adjustable Zener diode is connected to the timing module and one end of the ninth resistor and grounded through the tenth resistor, the other end of the ninth resistor is connected to the cathode of the third diode, and the anode of the third diode is connected to the feedback terminal of the drive device.
5. A short-circuit protection circuit for a switching power supply according to claim 4, characterized in that, The state detection module includes a first inverter, a fourth diode, a fifth diode, and a first logic chip; The input terminal of the first inverter is connected to the cathode of the first adjustable Zener diode, the output terminal of the first inverter is connected to the B terminal of the first logic chip, the A terminal of the first logic chip is connected to the cathodes of the fourth diode and the fifth diode, the anode of the fifth diode is connected to the Y terminal of the first logic chip and the timing module, and the anode of the fourth diode is connected to the non-inverting terminal of the first operational amplifier.
6. A short-circuit protection circuit for a switching power supply according to claim 5, characterized in that, The timing module includes a second power transistor, a seventh diode, an eleventh resistor, a seventh capacitor, a first timer, an eighth capacitor, a twelfth resistor, a first switching transistor, and a sixth diode; The drain of the second power transistor is connected to the first terminal of the power interface. The source of the second power transistor is connected to the cathode of the seventh diode, the collector of the first switching transistor, the fourth and eighth terminals of the first timer, and is connected to the anode of the seventh diode, one end of the seventh capacitor, the sixth and second terminals of the first timer through the eleventh resistor. The fifth terminal of the first timer is connected to the first terminal of the first timer, the other end of the seventh capacitor, one end of the twelfth resistor, and ground through the eighth capacitor. The emitter of the first switching transistor is connected to the anode of the sixth diode and the other end of the twelfth resistor. The cathode of the sixth diode is connected to the control terminal of the first adjustable Zener diode. The gate of the second power transistor is connected to the Y terminal of the first logic chip.