CN214124806U - Overvoltage protection circuit for output voltage of switching power supply - Google Patents
Overvoltage protection circuit for output voltage of switching power supply Download PDFInfo
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- CN214124806U CN214124806U CN202023067005.6U CN202023067005U CN214124806U CN 214124806 U CN214124806 U CN 214124806U CN 202023067005 U CN202023067005 U CN 202023067005U CN 214124806 U CN214124806 U CN 214124806U
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Abstract
The embodiment of the utility model discloses switching power supply output voltage overvoltage crowbar, including zener diode DZ1, resistance R1, photoelectric coupler PC1, resistance R2, silicon controlled rectifier SCR1 and resistance R3; the anode of the voltage stabilizing diode DZ1 is connected with one end of a resistor R1, the other end of the resistor R1 is connected with the input anode of a photoelectric coupler PC1, one end of the resistor R2 is connected with the input collector of a photoelectric coupler PC1, the other end of the resistor R2 is connected with the power supply end of a PWM chip of the switching power supply and the anode of a silicon controlled rectifier SCR1, the cathode of the silicon controlled rectifier SCR1 is connected with one end of a resistor R3, and the other end of the resistor R3 is connected with the control electrode of the silicon controlled rectifier SCR 1. The utility model discloses not only can stop switching power supply output high pressure and damage the singlechip when switching power supply's output voltage surpasses the settlement voltage rapidly, sensitivity is high moreover, simple structure, and is with low costs.
Description
Technical Field
The embodiment of the utility model provides a relate to the electronic circuit field, especially relate to a switching power supply output voltage overvoltage crowbar.
Background
At present, mostly all use the singlechip in the supporting terminal that uses of switching power supply, and the direct current voltage of singlechip work has minimum voltage and maximum voltage restriction, if switching power supply provides the direct current voltage of singlechip on the terminal low excessively, then the singlechip can not work, and if switching power supply provides the direct current voltage of singlechip on the terminal too high, then can lead to the singlechip to damage, so it is still very necessary to carry out overvoltage protection to switching power supply output voltage, just so can better protection singlechip and supporting load on the terminal, this problem is waited for to solve urgently.
SUMMERY OF THE UTILITY MODEL
In view of the above, the present invention provides an overvoltage protection circuit for output voltage of a switching power supply, which solves the above mentioned problems in the background art.
In order to achieve the above object, the embodiment of the present invention adopts the following technical solutions:
the embodiment of the utility model provides a switching power supply output voltage overvoltage crowbar, this circuit includes zener diode DZ1, resistance R1, photoelectric coupler PC1, resistance R2, silicon controlled rectifier SCR1 and resistance R3; wherein, the anode of the zener diode DZ1 is connected to one end of the resistor R1, the cathode of the zener diode DZ1 is connected to the positive output terminal Vout + of the switching power supply and the first output terminal of the DC/DC converter, the other end of the resistor R1 is connected to the input anode of the photocoupler PC1, the input cathode of the photocoupler PC1 is connected to the negative output terminal Vout-of the switching power supply and the second output terminal of the DC/DC converter, one end of the resistor R2 is connected to the input collector of the photocoupler PC1, the other end of the resistor R2 is connected to the power supply terminal of the PWM chip of the switching power supply, the anode of the thyristor SCR1, one end of the resistor R4 and the power supply VCC for supplying power to the PWM chip, the other end of the resistor R4 is connected to the positive input terminal of the switching power supply and the first input terminal of the Vin/DC converter, the cathode of the thyristor SCR1 is connected to one end of the resistor R3, the negative input terminal Vin-of the switching power supply, The second input end of the DC/DC converter is connected, and the other end of the resistor R3 is connected with the control electrode of the silicon controlled rectifier SCR1 and the input emitter of the photoelectric coupler PC 1.
Preferably, the overvoltage protection circuit for the output voltage of the switching power supply further comprises a capacitor C1; one end of the capacitor C1 is connected with the negative input terminal Vin-of the switch power supply, and the other end is connected with the control electrode of the silicon controlled SCR 1.
The utility model discloses technical scheme not only can stop switching power supply output high pressure and damage the singlechip rapidly when switching power supply output voltage surpasses the settlement voltage, moreover the utility model discloses sensitivity is high, circuit structure is simple, and is with low costs, suitable popularization and application.
Drawings
In order to more clearly illustrate and understand the technical solutions in the embodiments of the present invention, the drawings required to be used in the description of the background and embodiments of the present invention will be briefly introduced below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the contents of the embodiments of the present invention and the drawings without creative efforts.
Fig. 1 is an embodiment of the present invention provides an overvoltage protection circuit for output voltage of a switching power supply.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.
As shown in fig. 1, fig. 1 is a circuit for protecting overvoltage of output voltage of a switching power supply according to an embodiment of the present invention.
The embodiment provides an overvoltage protection circuit for output voltage of a switching power supply, which comprises a voltage stabilizing diode DZ1, a resistor R1, a photoelectric coupler PC1, a resistor R2, a silicon controlled rectifier SCR1 and a resistor R3. In this embodiment, the anode of the zener diode DZ1 is connected to one end of the resistor R1, the cathode of the zener diode DZ1 is connected to the positive output terminal Vout + of the switching power supply and the first output terminal of the DC/DC converter, the other end of the resistor R1 is connected to the input anode of the photocoupler PC1, the input cathode of the photocoupler PC1 is connected to the negative output terminal Vout-of the switching power supply and the second output terminal of the DC/DC converter, one end of the resistor R2 is connected to the input collector of the photocoupler PC1, the other end of the resistor R2 is connected to the power supply terminal of the PWM chip of the switching power supply, the anode of the thyristor SCR1, one end of the resistor R4 and the power supply VCC for supplying power to the PWM chip of the switching power supply, the other end of the resistor R4 is connected to the positive input terminal of the switching power supply and the first input terminal of the DC/DC converter, and the cathode of the thyristor SCR1 is connected to one end of the resistor R3, The negative electrode input end Vin-of the switching power supply and the second input end of the DC/DC converter are connected, and the other end of the resistor R3 is connected with the control electrode of the silicon controlled rectifier SCR1 and the input emitter of the photoelectric coupler PC 1.
When the overvoltage protection device works, after the output voltage of the switching power supply exceeds the set voltage value of the voltage stabilizing diode DZ1, the output voltage enables the input end of the photoelectric coupler PC1 to be conducted through the voltage stabilizing diode DZ1 and the resistor R1, so that the output end of the photoelectric coupler PC1 is also conducted, after the output end of the photoelectric coupler PC1 is conducted, the power VCC which supplies power to the PWM chip of the switching power supply triggers the trigger electrode of the silicon controlled rectifier SCR1 through the resistor R2 and the resistor R3, so that the silicon controlled rectifier SCR1 is conducted, the VCC which supplies power to the PWM chip of the switching power supply is pulled down after the SCR1 is conducted, so that the PWM chip of the switching power supply stops working, once the PWM chip of the switching power supply stops working, the output voltage of the switching power supply cannot be output at high voltage naturally, and the overvoltage protection function of the output voltage of the switching power supply is realized. Illustratively, the overvoltage protection circuit for the output voltage of the switching power supply in the embodiment further comprises a capacitor C1; one end of the capacitor C1 is connected with the negative input terminal Vin-of the switch power supply, and the other end is connected with the control electrode of the silicon controlled SCR 1. The capacitor C1 can effectively prevent the SCR1 from being triggered by mistake.
The utility model discloses technical scheme not only can stop switching power supply output high pressure and damage the singlechip rapidly when switching power supply output voltage surpasses the settlement voltage, moreover the utility model discloses the action is sensitive, and circuit structure is simple, and is with low costs, suitable popularization and application.
Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention; such modifications and substitutions do not depart from the spirit and scope of the present invention.
Claims (2)
1. The overvoltage protection circuit for the output voltage of the switching power supply is characterized by comprising a voltage stabilizing diode DZ1, a resistor R1, a photoelectric coupler PC1, a resistor R2, a silicon controlled rectifier SCR1 and a resistor R3; wherein, the anode of the zener diode DZ1 is connected to one end of the resistor R1, the cathode of the zener diode DZ1 is connected to the positive output terminal Vout + of the switching power supply and the first output terminal of the DC/DC converter, the other end of the resistor R1 is connected to the input anode of the photocoupler PC1, the input cathode of the photocoupler PC1 is connected to the negative output terminal Vout-of the switching power supply and the second output terminal of the DC/DC converter, one end of the resistor R2 is connected to the input collector of the photocoupler PC1, the other end of the resistor R2 is connected to the power supply terminal of the PWM chip of the switching power supply, the anode of the thyristor SCR1, one end of the resistor R4 and the power supply VCC for supplying power to the PWM chip, the other end of the resistor R4 is connected to the positive input terminal of the switching power supply and the first input terminal of the Vin/DC converter, the cathode of the thyristor SCR1 is connected to one end of the resistor R3, the negative input terminal Vin-of the switching power supply, The second input end of the DC/DC converter is connected, and the other end of the resistor R3 is connected with the control electrode of the silicon controlled rectifier SCR1 and the input emitter of the photoelectric coupler PC 1.
2. The switching power supply output voltage overvoltage protection circuit according to claim 1, further comprising a capacitor C1; one end of the capacitor C1 is connected with the negative input terminal Vin-of the switch power supply, and the other end is connected with the control electrode of the silicon controlled SCR 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202023067005.6U CN214124806U (en) | 2020-12-17 | 2020-12-17 | Overvoltage protection circuit for output voltage of switching power supply |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202023067005.6U CN214124806U (en) | 2020-12-17 | 2020-12-17 | Overvoltage protection circuit for output voltage of switching power supply |
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| CN214124806U true CN214124806U (en) | 2021-09-03 |
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| CN202023067005.6U Active CN214124806U (en) | 2020-12-17 | 2020-12-17 | Overvoltage protection circuit for output voltage of switching power supply |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023184478A1 (en) * | 2022-04-01 | 2023-10-05 | Nokia Shanghai Bell Co., Ltd. | Time sequence protection circuit, electronic device and method for controlling controlled circuit |
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2020
- 2020-12-17 CN CN202023067005.6U patent/CN214124806U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023184478A1 (en) * | 2022-04-01 | 2023-10-05 | Nokia Shanghai Bell Co., Ltd. | Time sequence protection circuit, electronic device and method for controlling controlled circuit |
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