Self-locking short-circuit protection circuit
Through the self-locking short-circuit protection circuit design, using a PNP transistor and resistor combination, the power output is promptly shut down when the load is short-circuited to prevent damage to electronic components, and the output is restored when the load returns to normal. This solves the problems of frequent fuse replacement and delayed fusing, and improves the practicality and reliability of the circuit.
Patent Information
- Application Number
- CN202422589441.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-25
- Publication Date
- 2025-10-17
- Estimated Expiration
- 2034-10-25
AI Technical Summary
In existing short-circuit protection circuits, frequent fuse replacement and delayed blowing cause damage to electronic components, resulting in high maintenance costs and the risk of electronic components being burned before the fuse blows.
A self-locking short-circuit protection circuit is used, using the first and second PNP transistors and a resistor design. When the load is short-circuited, the second PNP transistor is turned on and the first PNP transistor is turned off, preventing damage to the power supply electronic components. The output is restored through the reset circuit when the load returns to normal.
It effectively prevents power electronic components from being burned, reduces maintenance costs, and improves the practicality and reliability of the circuit.
Smart Images
Figure CN223451616U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to short circuit protection technical field especially relates to a self locking short circuit protection circuit. BACKGROUND
[0002] When the internal short circuit of the load occurs, the electronic components in the power supply will be damaged, and safety accidents may also occur.
[0003] At present, the main way to realize short circuit protection is to use a fuse, which will automatically melt when the current is too large. This short circuit protection circuit needs to frequently replace the fuse, which wastes manpower and material resources, and the circuit maintenance cost is high. In addition, it takes a certain time for the fuse to melt, and when the current is too large, the fuse may not have melted, and the electronic components in the power supply may have been burned out. UTILITY MODEL CONTENTS
[0004] The utility model discloses a self locking short circuit protection circuit, and the control end of the second switch is connected with the output power supply and the load through the first resistance, and when the load short circuit, the second switch is turned on, and the first switch is turned off, which effectively prevents the electronic components in the power supply from being burned out.
[0005] To solve the above technical problems, the utility model adopts the following technical scheme:
[0006] One aspect of the utility model discloses a self locking short circuit protection circuit, which comprises a first switch and a second switch, the control end of the first switch is turned on when receiving a low level signal, the control end of the second switch is turned on when receiving a low level signal, the input end of the first switch and the input end of the second switch all receive input power supply, the output end of the first switch is used to provide output power supply to the load, and the output end of the second switch is connected with the control end of the first switch.
[0007] In some embodiments, the first switch employs a first PNP transistor, the second switch employs a second PNP transistor, the emitter of the first PNP transistor and the emitter of the second PNP transistor both receive an input power supply, the collector of the first PNP transistor is used to provide an output power supply to a load, the collector of the second PNP transistor is connected to the base of the first PNP transistor, and the base of the second PNP transistor is connected to one end of the first resistor and one end of the second resistor.
[0008] In some embodiments, the self-locking short-circuit protection circuit further comprises a fourth resistor, and the base of the second PNP transistor is connected to one end of the first resistor and one end of the second resistor through the fourth resistor.
[0009] In some embodiments, the self-locking short-circuit protection circuit further comprises a first capacitor, one end of the first capacitor is connected to the emitter of the first PNP transistor and the emitter of the second PNP transistor, and the other end of the first capacitor is connected to the base of the second PNP transistor; and the self-locking short-circuit protection circuit further comprises a second capacitor, one end of the second capacitor is connected to the input end of the first switch and the input end of the second switch, and the other end of the second capacitor is connected to the output end of the second switch, the control end of the first switch, and one end of the third resistor.
[0010] In some embodiments, the self-locking short-circuit protection circuit further comprises a reset circuit, the detection end of the reset circuit is connected to one end of the first resistor, one end of the second resistor, one end of the fourth resistor, and the output end of the reset circuit, the input end of the reset circuit is connected to an input power supply, and the other end of the fourth resistor is connected to the base of the second PNP transistor.
[0011] In some embodiments, the reset circuit comprises a master control chip, a fifth resistor, and a third PNP transistor, the emitter of the third PNP transistor is connected to an input power supply, the collector of the third PNP transistor is connected to one end of the first resistor, one end of the second resistor, one end of the fourth resistor, and the detection end of the master control chip, the base of the third PNP transistor is connected to one end of the fifth resistor, and the other end of the fifth resistor is connected to the output end of the master control chip.
[0012] In some embodiments, the reset circuit further comprises a stabilizing diode, the negative electrode of the stabilizing diode is connected to the base of the third PNP transistor, and the positive electrode of the stabilizing diode is connected to the output end of the master control chip through the fifth resistor.
[0013] In some embodiments, the reset circuit further comprises a voltage stabilizing chip, a third capacitor and a fourth capacitor, one end of the third capacitor is connected to an input end of the voltage stabilizing chip and an input power supply, an output end of the voltage stabilizing chip is connected to one end of the fourth capacitor and a power input end of the master control chip, and a ground end of the voltage stabilizing chip, the other end of the third capacitor and the other end of the fourth capacitor are all grounded.
[0014] According to the self-locking short-circuit protection circuit, the base of the second PNP triode is connected to the ground through the second resistor, and is also connected to the output power supply and the load through the first resistor, when the load is short-circuited, the base of the second PNP triode receives a low level, the second PNP triode is turned on, the base of the first PNP triode receives a high level, and the first PNP triode is turned off, so that the electronic components in the power supply are effectively prevented from being burned out. The reset circuit is adopted, and the first PNP triode can restore normal output when the load recovers from short-circuit, so that the overall practicability is improved.
[0015] It should be understood that the general description above and the following detailed description are only exemplary and cannot limit the present disclosure. BRIEF DESCRIPTION OF DRAWINGS
[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.
[0017] Figure 1 The self-locking short-circuit protection circuit according to the embodiment is shown in the schematic diagram. DETAILED DESCRIPTION
[0018] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the present application.
[0019] The terms "first", "second", "third" are only used for description purpose, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second", "third" can explicitly or implicitly include one or more features. In the description of the present application, unless otherwise specified, the meaning of "multiple" is two or more.
[0020] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integral connection; mechanical connection, electrical connection; direct connection, indirect connection through an intermediate medium, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.
[0021] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these example embodiments are provided so that the description of this disclosure will be more comprehensive and complete, and will fully convey the concepts of the example embodiments to those skilled in the art. The accompanying drawings are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale. Identical reference numerals in the figures indicate identical or similar parts, and thus repeated descriptions thereof will be omitted.
[0022] The technical solutions of the embodiments of the present application are briefly described below:
[0023] According to some embodiments, Figure 1 As shown, the present application provides a self-locking short-circuit protection circuit, which includes:
[0024] a first switch Q1 and a second switch Q2, wherein the first switch Q1 is turned on when a control terminal receives a low-level signal, and the second switch Q2 is turned on when a control terminal receives a low-level signal, the input terminals of the first switch Q1 and the second switch Q2 both receive input power, the output terminal of the first switch Q1 is used to provide output power to a load, and the output terminal of the second switch Q2 is connected to the control terminal of the first switch Q1;
[0025] A first resistor R1, a second resistor R2, and a third resistor R3 are provided. The control end of the second switch Q2 is connected to one end of the first resistor R1 and one end of the second resistor R2. The other end of the first resistor R1 is connected to the output end of the first switch Q1. The output end of the second switch Q2 and the control end of the first switch Q1 are connected to one end of the third resistor R3. The other end of the second resistor R2 and the other end of the third resistor R3 are grounded.
[0026] The second resistor R2 is larger than the third resistor R3.
[0027] Based on the operating principle of the above embodiment, during normal operation, the control terminal of the first switch Q1 receives a low-level signal through the third resistor R3, turning it on. The output terminal of the first switch Q1 provides output power to the load. The control terminal of the second switch Q2 is grounded through the second resistor R2 and is simultaneously pulled up by the output power through the first resistor R1. The second switch Q2 is turned off, and the first switch Q1 outputs normally.
[0028] When the load is short-circuited, the control end of the second switch Q2 is pulled down by the second resistor R2 and the first resistor R1. The control end of the second switch Q2 receives a low-level signal and turns on. The second switch Q2 outputs a high-level signal to the control end of the first switch Q1, turning off the first switch Q1. This effectively prevents the electronic components in the power supply from burning out.
[0029] When the load is momentarily short-circuited and then restored, the control terminal of the second switch Q2 is pulled down by the second resistor R2 because the control terminal of the second switch Q2 does not receive a high-level signal through the first resistor R1. The second switch Q2 remains on, and the control terminal of the first switch Q1 continues to receive a high-level signal output by the second switch Q2. The first switch Q1 is self-locked and turned off.
[0030] The following is in conjunction with the appendix of this manual Figure 1 , the preferred embodiments of the present disclosure are further elaborated in detail.
[0031] According to some embodiments, Figure 1 As shown, the first switch Q1 adopts a first PNP transistor Q1, and the second switch Q2 adopts a second PNP transistor Q2. The emitter of the first PNP transistor Q1 and the emitter of the second PNP transistor Q2 both receive input power, the collector of the first PNP transistor Q1 is used to provide output power to the load, the collector of the second PNP transistor Q2 is connected to the base of the first PNP transistor Q1, and the base of the second PNP transistor Q2 is connected to one end of the first resistor R1 and one end of the second resistor R2.
[0032] The first switch Q1 may also be an electronic component with a switch function, such as a MOS tube, a thyristor, and an optical coupler, which is not limited in this application.
[0033] Based on the operating principle of the above embodiment, during normal operation, the base of the first PNP transistor Q1 receives a low-level signal through the third resistor R3 and turns on, and the collector of the first PNP transistor Q1 provides output power to the load. The base of the second PNP transistor Q2 is grounded through the second resistor R2 and is simultaneously pulled up by the output power through the first resistor R1, turning off the second PNP transistor Q2 and allowing the first PNP transistor Q1 to output normally.
[0034] When the load is short-circuited, the base of the second PNP transistor Q2 is pulled down by the second resistor R2 and the first resistor R1 at the same time, the base of the second PNP transistor Q2 receives a low-level signal to turn on, the second PNP transistor Q2 outputs a high-level signal to the base of the first PNP transistor Q1, the first PNP transistor Q1 is turned off, effectively preventing the electronic components in the power supply from being burned out.
[0035] When the load is short-circuited and then restored, the base of the second PNP transistor Q2 cannot receive a high-level signal through the first resistor R1, so the base of the second PNP transistor Q2 is pulled down by the second resistor R2, the second PNP transistor Q2 continues to be turned on, the base of the first PNP transistor Q1 continuously receives a high-level signal output by the second PNP transistor Q2, and the first PNP transistor Q1 is self-locked off.
[0036] The base of the second PNP transistor Q2 in the application is connected to the ground through the second resistor R2, and is also connected to the output power supply and the load through the first resistor R1. When the load is short-circuited, the base of the second PNP transistor Q2 receives a low-level signal, the second PNP transistor Q2 is turned on, the base of the first PNP transistor Q1 receives a high-level signal, and the first PNP transistor Q1 is turned off, effectively preventing the electronic components in the power supply from being burned out.
[0037] According to some embodiments, as shown in Figure 1 The self-locking short-circuit protection circuit further comprises a fourth resistor R4, and the base of the second PNP transistor Q2 is connected to one end of the first resistor R1 and one end of the second resistor R2 through the fourth resistor R4.
[0038] The sum of the resistance values of the second resistor R2 and the fourth resistor R4 is greater than the resistance value of the third resistor R3.
[0039] According to some embodiments, as shown in Figure 1 The self-locking short-circuit protection circuit further comprises a first capacitor C1, one end of the first capacitor C1 is connected to the emitter of the first PNP transistor Q1 and the emitter of the second PNP transistor Q2, and the other end of the first capacitor C1 is connected to the base of the second PNP transistor Q2.
[0040] Further, as shown in Figure 1 The self-locking short-circuit protection circuit further comprises a second capacitor C2, one end of the second capacitor C2 is connected to the input end of the first switch Q1 and the input end of the second switch Q2, and the other end of the second capacitor C2 is connected to the output end of the second switch Q2, the control end of the first switch Q1, and one end of the third resistor R3.
[0041] According to some embodiments, as shown in Figure 1As shown, the self-locking short-circuit protection circuit further comprises a reset circuit, a detection end AD_CHK of the reset circuit is connected with one end of the first resistor R1, one end of the second resistor R2, one end of the fourth resistor R4 and an output end of the reset circuit, an input end of the reset circuit is connected with an input power supply, and the other end of the fourth resistor R4 is connected with a base of the second PNP transistor Q2.
[0042] Based on the working principle of the above embodiment, when the load recovers from short circuit, the output end of the reset circuit outputs a high-level signal, the second PNP transistor Q2 is turned off, the base of the first PNP transistor Q1 receives a low-level signal through the third resistor R3, and the first PNP transistor Q1 recovers normal output.
[0043] The reset circuit is adopted in the application, the first PNP transistor can recover normal output when the load recovers from short circuit, and the overall practicability is improved.
[0044] According to some embodiments, as Figure 1 As shown, the reset circuit comprises a master control chip, a fifth resistor R5 and a third PNP transistor Q3, an emitter of the third PNP transistor Q3 is connected with an input power supply, a collector of the third PNP transistor Q3 is connected with one end of the first resistor R1, one end of the second resistor R2, one end of the fourth resistor R4 and a detection end AD_CHK of the master control chip, a base of the third PNP transistor Q3 is connected with one end of the fifth resistor R5, and the other end of the fifth resistor R5 is connected with an output end of the master control chip.
[0045] Based on the working principle of the above embodiment, when the load recovers from short circuit, the output end of the master control chip outputs a low-level signal, the third PNP transistor Q3 outputs a high-level signal to be turned on, the second PNP transistor Q2 is turned off, the base of the first PNP transistor Q1 receives a low-level signal through the third resistor R3, and the first PNP transistor Q1 recovers normal output.
[0046] Further, as Figure 1 As shown, the reset circuit further comprises a stabilizing diode Z, a negative electrode of the stabilizing diode Z is connected with the base of the third PNP transistor Q3, and a positive electrode of the stabilizing diode Z is connected with the output end of the master control chip through the fifth resistor R5.
[0047] Further, as Figure 1As shown, the reset circuit further comprises a voltage stabilizing chip U2, a third capacitor C3 and a fourth capacitor C4, one end of the third capacitor C3 and an input power source are connected to an input end of the voltage stabilizing chip U2, an output end of the voltage stabilizing chip U2 is connected to one end of the fourth capacitor C4 and a power input end of the main control chip, and a grounding end of the voltage stabilizing chip U2, the other end of the third capacitor C3 and the other end of the fourth capacitor C4 are all grounded.
[0048] In the description of the above-described embodiments, specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.
[0049] While the present disclosure has been described with reference to several exemplary embodiments, it is understood that the words that have been used are words of description and illustration, rather than words of limitation. As such, the above-described embodiments are contemplated to be illustrative in all respects and not restrictive, and the scope of the present disclosure is not limited to the above-described embodiments but includes all modifications and equivalents falling within the spirit and scope of the appended claims.
Claims
1. A self-locking short-circuit protection circuit, characterized in that: The self-locking short-circuit protection circuit comprises: a first switch and a second switch, wherein the first switch is turned on when a control terminal receives a low-level signal, and the second switch is turned on when a control terminal receives a low-level signal, the input terminal of the first switch and the input terminal of the second switch both receive an input power supply, the output terminal of the first switch is used to provide an output power supply to a load, and the output terminal of the second switch is connected to the control terminal of the first switch; a first resistor, a second resistor, and a third resistor, wherein the control end of the second switch is connected to one end of the first resistor and one end of the second resistor, the other end of the first resistor is connected to the output end of the first switch, the output end of the second switch and the control end of the first switch are connected to one end of the third resistor, and the other end of the second resistor and the other end of the third resistor are grounded.
2. The self-locking short-circuit protection circuit according to claim 1, characterized in that: The first switch uses a first PNP transistor, and the second switch uses a second PNP transistor. The emitter of the first PNP transistor and the emitter of the second PNP transistor both receive input power, the collector of the first PNP transistor is used to provide output power to the load, the collector of the second PNP transistor is connected to the base of the first PNP transistor, and the base of the second PNP transistor is connected to one end of the first resistor and one end of the second resistor.
3. The self-locking short-circuit protection circuit according to claim 2, characterized in that: The self-locking short-circuit protection circuit further includes a fourth resistor, and the base of the second PNP transistor is connected to one end of the first resistor and one end of the second resistor through the fourth resistor.
4. The self-locking short-circuit protection circuit according to claim 3, characterized in that: The self-locking short-circuit protection circuit further includes a first capacitor, one end of the first capacitor is connected to the emitter of the first PNP transistor and the emitter of the second PNP transistor, and the other end of the first capacitor is connected to the base of the second PNP transistor; The self-locking short-circuit protection circuit also includes a second capacitor, one end of which is connected to the input end of the first switch and the input end of the second switch, and the other end of the second capacitor is connected to the output end of the second switch, the control end of the first switch and one end of the third resistor.
5. The self-locking short-circuit protection circuit according to claim 3, characterized in that: The self-locking short-circuit protection circuit also includes a reset circuit, wherein the detection end of the reset circuit is connected to one end of the first resistor, one end of the second resistor, one end of the fourth resistor and the output end of the reset circuit, the input end of the reset circuit is connected to the input power supply, and the other end of the fourth resistor is connected to the base of the second PNP transistor.
6. The self-locking short-circuit protection circuit according to claim 5, characterized in that: The reset circuit includes a main control chip, a fifth resistor and a third PNP transistor, the emitter of the third PNP transistor is connected to the input power supply, the collector of the third PNP transistor is connected to one end of the first resistor, one end of the second resistor, one end of the fourth resistor and the detection end of the main control chip, the base of the third PNP transistor is connected to one end of the fifth resistor, and the other end of the fifth resistor is connected to the output end of the main control chip.
7. The self-locking short-circuit protection circuit according to claim 6, characterized in that: The reset circuit further includes a voltage stabilizing diode, the cathode of the voltage stabilizing diode is connected to the base of the third PNP transistor, and the anode of the voltage stabilizing diode is connected to the output end of the main control chip through the fifth resistor.
8. The self-locking short-circuit protection circuit according to claim 6, characterized in that: The reset circuit also includes a voltage stabilizing chip, a third capacitor and a fourth capacitor. The input end of the voltage stabilizing chip is connected to one end of the third capacitor and the input power supply, the output end of the voltage stabilizing chip is connected to one end of the fourth capacitor and the power input end of the main control chip, and the ground end of the voltage stabilizing chip, the other end of the third capacitor and the other end of the fourth capacitor are all grounded.