CN202384991U - Overvoltage protection circuit of switching power supply - Google Patents
Overvoltage protection circuit of switching power supply Download PDFInfo
- Publication number
- CN202384991U CN202384991U CN2011205244428U CN201120524442U CN202384991U CN 202384991 U CN202384991 U CN 202384991U CN 2011205244428 U CN2011205244428 U CN 2011205244428U CN 201120524442 U CN201120524442 U CN 201120524442U CN 202384991 U CN202384991 U CN 202384991U
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- CN
- China
- Prior art keywords
- power supply
- switching power
- protective circuit
- reference voltage
- optocoupler
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
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Abstract
The utility model discloses an overvoltage protection circuit of a switching power supply. The overvoltage protection circuit is characterized by comprising a reference voltage, an input voltage, a protective circuit and an optocoupler, wherein the reference voltage and the input voltage are respectively connected to the protective circuit, the protective circuit is connected with the input end of the optocoupler, and the output end of the optocoupler is connected with the switching power supply. Overvoltage reference is regulated by using a potentiometer, and self-locking of the protective circuit is realized by using the clamping action of a diode, thus, a load and the switching power supply are effectively protected, and the service life of the switching power supply is greatly prolonged.
Description
Technical field
The utility model relates to a kind of overvoltage crowbar, is specifically related to a kind of overvoltage crowbar that is used for the beginning power supply, belongs to the electronic circuit technology field.
Background technology
In recent years, Switching Power Supply is widely used, but its protective circuit design is not fully up to expectations; Particularly in the pulse load Switching Power Supply; Because high voltage source is unstable, cause the Switching Power Supply transition at load or input voltage mutation, and general overvoltage crowbar can not be locked fully; Can only make the output of PWM modulator block 1-2 cycle at most, high pressure obtains opening again then.This traditional overvoltage protection is the protection switch power supply effectively, only can make the voltage output of Switching Power Supply fluctuated, causes output voltage too high and damage load and Switching Power Supply, and the useful life of Switching Power Supply is short.
The utility model content
Be to solve the deficiency of prior art, the purpose of the utility model is the Switching Power Supply overvoltage crowbar that a kind of effectively protection switch power supply is provided, prolongs its useful life.
For achieving the above object, the utility model is to realize through following technical scheme:
A kind of Switching Power Supply overvoltage crowbar; It is characterized in that; Comprise reference voltage, input voltage, protective circuit and optocoupler; Described reference voltage and input voltage are connected respectively to protective circuit, and described protective circuit then is connected with the input of optocoupler, and the output of optocoupler connects Switching Power Supply.
Wherein, Described protective circuit comprises operational amplifier, resistance R 2 and diode VD1; Described resistance R 2 is common parallelly connected with described operational amplifier with diode VD1 series connection back; And the anodal of described R2 and operational amplifier all is connected with input voltage, and the negative pole of described operational amplifier then connects reference voltage.
Described reference voltage then comprises resistance R 3, VS and potentiometer RP, connects with described resistance R 3 jointly after described potentiometer RP and the VS parallel connection.
Further, the scope of described reference voltage is 5V～6V, and RP sets through potentiometer.
The beneficial effect of the utility model is: the utility model utilizes potentiometer to regulate the overvoltage benchmark, and utilizes the clamping action of diode, has realized the self-locking of protective circuit, has protected load and Switching Power Supply effectively, has prolonged the useful life of Switching Power Supply greatly.
Description of drawings
Fig. 1 is the structural representation of the utility model one embodiment.
Embodiment
Below in conjunction with accompanying drawing and specific embodiment the utility model is done concrete introduction.
Fig. 1 is the structural representation of the utility model one embodiment.
As shown in Figure 1: a kind of Switching Power Supply overvoltage crowbar; Comprise reference voltage V ref, input voltage vin, protective circuit and optocoupler TP; Described reference voltage V ref and input voltage vin are connected respectively to protective circuit; Described protective circuit then is connected with the input of optocoupler TP, and the output of optocoupler TP connects Switching Power Supply, in this execution mode; The output of described optocoupler TP comprises C end and E end, and described protective circuit is to be connected with the input of described optocoupler TP through a resistance R 5.
Wherein, In this execution mode; Described protective circuit comprises operational amplifier HA17741, resistance R 2 and diode VD1, and described resistance R 2 is common parallelly connected with described operational amplifier HA17741 with diode VD1 series connection back, and the anodal of described R2 and operational amplifier HA17741 all is connected through a resistance R 1 with the output of input voltage vin;, the negative pole of described operational amplifier HA17741 then is connected with reference voltage V ref through a resistance R 4.
Described reference voltage V ref then comprises resistance R 3, VS and potentiometer RP, connects with described resistance R 3 jointly after described potentiometer RP and the VS parallel connection.And the scope of regulating reference voltage through setting potentiometer RP is 5V～6V.
The operation principle of the utility model is: the reference voltage V ref that resistance R 3, VS and potentiometer Rp constitute; The setting of this voltage will be according to the highest permission output voltage design of Switching Power Supply; Can set through the RP potentiometer, be generally about 5V ~ 6V, and input voltage vin be a feedback voltage; In this execution mode, the core devices of entire circuit is operational amplifier HA17741, diode VD1 and resistance R 2.When input voltage vin>during reference voltage V ref; Operational amplifier HA17741 exports high level (being generally the supply power voltage of operational amplifier); The output clamper that make operational amplifier HA17741 through diode VD1 and resistance R 2 this moment is in high level, so optocoupler TP is in operating state always; And the C of optocoupler TP, E end can pin the Switching Power Supply benchmark, and then reduces output voltage protection switch power supply.
The utility model utilizes potentiometer to regulate the overvoltage benchmark, and utilizes the clamping action of diode, has realized the self-locking of protective circuit, has protected load and Switching Power Supply effectively, has prolonged the useful life of Switching Power Supply greatly.
The foregoing description does not limit the utility model in any form, and all employings are equal to the technical scheme that mode obtained of replacement or equivalent transformation, all drop in the protection range of the utility model.
Claims (4)
1. Switching Power Supply overvoltage crowbar; It is characterized in that; Comprise reference voltage, input voltage, protective circuit and optocoupler; Described reference voltage and input voltage are connected respectively to protective circuit, and described protective circuit then is connected with the input of optocoupler, and the output of optocoupler connects Switching Power Supply.
2. a kind of Switching Power Supply overvoltage crowbar according to claim 1; It is characterized in that; Described protective circuit comprises operational amplifier, resistance R 2 and diode VD1; Described resistance R 2 is common parallelly connected with described operational amplifier with diode VD1 series connection back, and the positive pole of described R2 and operational amplifier all is connected with input voltage, and the negative pole of described operational amplifier then connects reference voltage.
3. a kind of Switching Power Supply overvoltage crowbar according to claim 1 is characterized in that described reference voltage comprises resistance R 3, VS and potentiometer RP, connects with described resistance R 3 jointly after described potentiometer RP and the VS parallel connection.
4. a kind of Switching Power Supply overvoltage crowbar according to claim 3 is characterized in that the scope of described reference voltage is 5V ~ 6V.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011205244428U CN202384991U (en) | 2011-12-15 | 2011-12-15 | Overvoltage protection circuit of switching power supply |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011205244428U CN202384991U (en) | 2011-12-15 | 2011-12-15 | Overvoltage protection circuit of switching power supply |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202384991U true CN202384991U (en) | 2012-08-15 |
Family
ID=46633462
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011205244428U Expired - Fee Related CN202384991U (en) | 2011-12-15 | 2011-12-15 | Overvoltage protection circuit of switching power supply |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN202384991U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108539977A (en) * | 2018-05-14 | 2018-09-14 | 武汉华星光电半导体显示技术有限公司 | Protect circuit and display panel |
| US10778004B2 (en) | 2018-05-14 | 2020-09-15 | Wuhan China Star Optoelectronics Semiconductor Display Technology Co., Ltd. | Protection circuit and display panel |
| EP4024689A1 (en) * | 2021-01-05 | 2022-07-06 | Rockwell Automation Technologies, Inc. | Direct current bus capacitor breakdown protection circuit for drives |
-
2011
- 2011-12-15 CN CN2011205244428U patent/CN202384991U/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108539977A (en) * | 2018-05-14 | 2018-09-14 | 武汉华星光电半导体显示技术有限公司 | Protect circuit and display panel |
| US10778004B2 (en) | 2018-05-14 | 2020-09-15 | Wuhan China Star Optoelectronics Semiconductor Display Technology Co., Ltd. | Protection circuit and display panel |
| EP4024689A1 (en) * | 2021-01-05 | 2022-07-06 | Rockwell Automation Technologies, Inc. | Direct current bus capacitor breakdown protection circuit for drives |
| US11404865B2 (en) | 2021-01-05 | 2022-08-02 | Rockwell Automation Technologies, Inc. | Direct current bus capacitor breakdown protection circuit for drives |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20120815 Termination date: 20151215 |
|
| EXPY | Termination of patent right or utility model |