DC output short-circuit protection circuit
The DC output short-circuit protection circuit, composed of diodes and resistors, utilizes resistor voltage division to detect the load status and realize the conduction control of the transistor, solving the problem of the lack of independent short-circuit protection in existing DC output circuits and achieving low-cost and high-efficiency short-circuit protection.
Patent Information
- Application Number
- CN202423323181.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2026-02-17
- Estimated Expiration
- 2034-12-31
AI Technical Summary
Existing DC output circuits lack independent short-circuit protection. Adding short-circuit protection circuits is complex, costly, and cumbersome.
The circuit structure consists of diode D1, resistors R1 and R2, transistors Q1, R3 and Q2, resistor R4, capacitors C1 and C2, resistors R5, R6 and R7. The load status is detected by the voltage divider between resistors R4 and R6, and the conduction control of transistors Q1 and Q2 is realized to achieve short-circuit protection.
With its simple structure and low cost, it is suitable for multi-output scenarios, has independent protection functions, fast response speed, and requires no additional external lines, making it suitable for widespread application.
Smart Images
Figure CN223928074U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of electronic circuits, and in particular to a DC output short-circuit protection circuit. Background Technology
[0002] Most electronic components and integrated circuits require a stable, non-changing current to operate normally, and DC power outputs are commonly used to power various electronic devices. However, existing DC output circuits do not provide independent short-circuit protection for each output. Moreover, adding short-circuit protection circuits to a particular output later is not only complex in terms of the circuit itself, but also requires complex external wiring, is cumbersome to operate, and is costly. This problem urgently needs to be solved. Utility Model Content
[0003] In view of this, the present invention provides a DC output short-circuit protection circuit to solve the problems mentioned in the background section above.
[0004] To achieve the above objectives, the embodiments of this utility model adopt the following technical solutions:
[0005] This utility model embodiment provides a DC output short-circuit protection circuit, which includes a diode D1, a resistor R1, a transistor Q1, a resistor R2, a resistor R3, a transistor Q2, a resistor R4, a capacitor C1, a capacitor C2, a resistor R5, a resistor R6, and a resistor R7. One end of the resistor R1 is connected to the cathode of the diode, the source of the transistor Q1, and one end of the resistor R2. The other end of the resistor R2 is connected to one end of the resistor R3 and the gate of the transistor Q1. The drain of the transistor Q1 is connected to the other end of the resistor R1, one end of the resistor R4, one end of the capacitor C1, and one end of the capacitor C2. The other end of the capacitor C1 is connected to one end of the capacitor C2, one end of the resistor R6, one end of the resistor R7, and the emitter of the transistor Q2. The other end of the resistor R7 is connected to one end of the resistor R5 and then to the base of the transistor Q2. The other end of the resistor R6 is connected to one end of the resistor R5 and the other end of the resistor R4. The collector of the transistor Q2 is connected to the other end of the resistor R3.
[0006] Preferably, the positive terminal of diode D1 is connected to the DC input terminal Vin, the source terminal of transistor Q1 is connected to the load input terminal Vout, and the emitter terminal of transistor Q2 is grounded to GND.
[0007] Preferably, the transistor Q1 is a MOSFET.
[0008] Preferably, the transistor Q2 is an NPN transistor.
[0009] In this embodiment of the invention, when the load connection is normal, the voltage is divided by resistors R4 and R6. At this time, the voltage is higher than the turn-on voltage of transistor Q2, so transistor Q2 is in the turn-on state. The gate (G) terminal of transistor Q1 is pulled low, so transistor Q1 is in the turn-on state. When there is a short circuit at the load connection, the voltage divided by resistors R4 and R6 cannot meet the turn-on condition of transistor Q2. The gate (G) voltage of transistor Q1 is the same as the source (S) voltage. Transistor Q1 turns off the output terminal of the load connection and there is no output, thus achieving DC output short circuit protection.
[0010] This utility model has a simple structure, low cost, strong versatility, and is suitable for widespread application. Attached Figure Description
[0011] To more clearly illustrate and understand the technical solutions in the embodiments of this utility model, the accompanying drawings used in the background technology and embodiment description of this utility model will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of this utility model and these drawings without creative effort.
[0012] Figure 1 A structural diagram of a DC output short-circuit protection circuit provided for an embodiment of this utility model. Detailed Implementation
[0013] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.
[0014] Example 1
[0015] like Figure 1 As shown, Figure 1 A structural diagram of a DC output short-circuit protection circuit provided for an embodiment of this utility model.
[0016] This embodiment provides a DC output short-circuit protection circuit, which includes a diode D1, a resistor R1, a transistor Q1, a resistor R2, a resistor R3, a transistor Q2, a resistor R4, a capacitor C1, a capacitor C2, a resistor R5, a resistor R6, and a resistor R7. One end of the resistor R1 is connected to the cathode of the diode, the source of the transistor Q1, and one end of the resistor R2. The other end of the resistor R2 is connected to one end of the resistor R3 and the gate of the transistor Q1. The drain of the transistor Q1 is connected to the other end of the resistor R1, one end of the resistor R4, one end of the capacitor C1, and one end of the capacitor C2. The other end of the capacitor C1 is connected to one end of the capacitor C2, one end of the resistor R6, one end of the resistor R7, and the emitter of the transistor Q2. The other end of the resistor R7 is connected to one end of the resistor R5 and then to the base of the transistor Q2. The other end of the resistor R6 is connected to one end of the resistor R5 and the other end of the resistor R4. The collector of the transistor Q2 is connected to the other end of the resistor R3.
[0017] In this embodiment, the anode of diode D1 is connected to the DC input terminal Vin, the source of transistor Q1 is connected to the load input terminal Vout, and the emitter of transistor Q2 is grounded to GND. Transistor Q1 is a MOSFET. Transistor Q2 is an NPN transistor.
[0018] In this embodiment, Vin is the DC input terminal, diode D1 is the diode to prevent reverse current from the output, and Vout is the load connection terminal. When Vout is normal, the voltage is divided by resistors R4 and R6. At this time, the voltage is higher than the conduction voltage of transistor Q2, and transistor Q2 is in the conducting state. The gate terminal of transistor Q1 is pulled low, and transistor Q1 is in the conducting state. When there is a short circuit in the output Vout, the voltage divided by resistors R4 and R6 cannot meet the conduction condition of transistor Q2. The gate terminal voltage of transistor Q1 is the same as the source terminal, transistor Q1 is turned off, and there is no output at the Vout output terminal. At this time, there is no effect on the input terminal Vin, thus realizing DC output short circuit protection. Moreover, the technical solution of this utility model has independent protection function for each output in the scenario with multiple outputs.
[0019] This invention employs a follower-type voltage detection, resulting in a fast response speed. It can be easily adapted to meet output voltage requirements by simply modifying the voltage point without adding any external circuitry. Furthermore, this invention involves few components, has a simple circuit structure, can be used in multi-output circuits, and provides independent protection for each output. All components are universal, inexpensive, and reliable, making it suitable for widespread application.
[0020] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it; although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.
Claims
1. A DC output short-circuit protection circuit, characterized by comprising: It comprises diode D1, resistor R1, triode Q1, resistor R2, resistor R3, triode Q2, resistor R4, capacitor C1, capacitor C2, resistor R5, resistor R6 and resistor R7; one end of the resistor R1 is connected with the negative pole of the diode, the source of the triode Q1 and one end of the resistor R2; the other end of the resistor R2 is connected with one end of the resistor R3 and the gate of the triode Q1; the drain of the triode Q1 is connected with the other end of the resistor R1, one end of the resistor R4, one end of the capacitor C1 and one end of the capacitor C2; the other end of the capacitor C1 is connected with one end of the capacitor C2, one end of the resistor R6, one end of the resistor R7 and the emitter of the triode Q2; the other end of the resistor R7 is connected with one end of the resistor R5 and the base of the triode Q2; the other end of the resistor R6 is connected with one end of the resistor R5 and the other end of the resistor R4; the collector of the triode Q2 is connected with the other end of the resistor R3.
2. The DC output short circuit protection circuit according to claim 1, characterized in that, The positive pole of the diode D1 is connected with the DC input end Vin; the source of the triode Q1 is connected with the load access end Vout; and the emitter of the triode Q2 is connected with the ground GND.
3. The DC output short-circuit protection circuit according to claim 1 or 2, characterized in that, The triode Q1 is a MOS tube.
4. The DC output short circuit protection circuit of claim 3, wherein, The triode Q2 is an NPN type triode.