CN203596738U - Switch power supply output overvoltage protection circuit - Google Patents
Switch power supply output overvoltage protection circuit Download PDFInfo
- Publication number
- CN203596738U CN203596738U CN201320839086.8U CN201320839086U CN203596738U CN 203596738 U CN203596738 U CN 203596738U CN 201320839086 U CN201320839086 U CN 201320839086U CN 203596738 U CN203596738 U CN 203596738U
- Authority
- CN
- China
- Prior art keywords
- voltage
- triode
- circuit
- output
- protection circuit
- 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
Links
- 239000003990 capacitor Substances 0.000 claims abstract description 8
- 239000003381 stabilizer Substances 0.000 claims abstract description 8
- 238000005070 sampling Methods 0.000 claims abstract description 5
- 230000000087 stabilizing effect Effects 0.000 claims description 21
- 230000000694 effects Effects 0.000 abstract description 2
- 230000003287 optical effect Effects 0.000 abstract 1
- 238000001914 filtration Methods 0.000 description 4
- 230000001629 suppression Effects 0.000 description 4
- 238000013024 troubleshooting Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 230000001681 protective effect Effects 0.000 description 3
- 230000015556 catabolic process Effects 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
Images
Landscapes
- Dc-Dc Converters (AREA)
- Emergency Protection Circuit Devices (AREA)
Abstract
The utility model discloses a switch power supply output overvoltage protection circuit. The overvoltage protection circuit comprises a voltage-stabilizer diode Z1, a capacitor C32, a resistor R38, and a triode Q3. The negative pole of the voltage-stabilizer diode Z1 is connected with the positive end of the output terminal of an output rectifier and filter circuit. The positive pole of the voltage-stabilizer diode Z1 is connected with the base electrode of the triode Q3. The capacitor C32 and the resistor R38 are connected in parallel between the base electrode and the emitter electrode of the triode Q3. The emitter electrode of the triode Q3 is grounded. The collector electrode of the triode Q3 is connected to a pin 2 of an optical coupler U2 in a voltage sampling feedback circuit. According to the utility model, the resistor R38 is employed to limit the current of the voltage-stabilizer diode Z1 and the conduction of the triode Q3 is used to control the sampling voltage of the voltage sampling feedback circuit so that a feedback can be supplied to an ON-OFF control circuit and thus the output voltage is reduced, thereby achieving the protection effect. When the protection circuit works, the voltage-stabilizer diode cannot be burnt and can restore to normal work automatically after faults are removed.
Description
Technical field
The utility model relates to a kind of switching power circuit, is specifically related to a kind of Switching Power Supply output overvoltage protection circuit.
Background technology
Figure 1 shows that traditional reverse exciting switching voltage regulator circuit diagram, it comprises input and electromagnetic interference suppression circuit, current rectifying and wave filtering circuit, transformer change-over circuit, ON-OFF control circuit, output rectifier and filter, voltage sample feedback circuit, overvoltage crowbar; Current rectifying and wave filtering circuit connects input and electromagnetic interference suppression circuit; the input of ON-OFF control circuit connection transformer change-over circuit, the output of output filter circuit connection transformer change-over circuit, voltage sample feedback circuit connects output rectifier and filter; the control IC that overvoltage crowbar is connected across the positive and negative terminal ON-OFF control circuit of output is integrated circuit U1; integrated circuit U1 has 6 pins, is respectively GND pin, FB pin; OPP/Latch pin; CS pin, Vcc pin, DRV pin.Voltage stabilizing didoe Z1 is connected across between the output both positive and negative polarity of output rectifier and filter, plays and punctures the effect of formula overvoltage protection.Its operation principle: in the time causing output voltage to raise after certain component failure in product; boosted voltage is directly added in the two ends of output voltage stabilizing didoe Z1; in the time that voltage is elevated to the avalanche voltage of its puncture voltage; at this moment the current spikes of voltage stabilizing didoe Z1 increases; because crossing thermal breakdown PN junction; make it be in short-circuit condition, be equivalent to output positive and negative charge short circuit, make circuit working at short-circuit protection state and it is to overvoltage protection.(annotation: GND----ground connection, FB----feedback, OPP/Latch----protect setting, CS----current detecting, the Vcc----U1 pin of powering, DRV----driving).
This Switching Power Supply protection philosophy is to utilize output voltage to be elevated to voltage stabilizing didoe avalanche breakdown voltage; make Switching Power Supply enter that short-circuit protection state realizes; voltage stabilizing didoe Z1 need to bear very large electric current; at this moment because not bearing too large electric current; cause voltage stabilizing didoe internal break; rather than short circuit, therefore this protection that relies on voltage stabilizing didoe completely, is not fully effective.When after trouble shooting, voltage stabilizing didoe Z1 has caused permanent damages, can not return to normal operating conditions, must change voltage stabilizing didoe Z1 and can normally work.
Utility model content
The utility model technical issues that need to address are to provide a kind of reliable and stable, and trouble shooting can recover normal work automatically, without the Switching Power Supply output overvoltage protection circuit of changing protection component.
For addressing the above problem; technical solution adopted in the utility model is: a kind of Switching Power Supply output overvoltage protection circuit; overvoltage crowbar comprises voltage-stabiliser tube two utmost point Z1, capacitor C 32, resistance R 38, triode Q3; wherein voltage stabilizing didoe Z1 negative pole connects the anode of the output of output rectifier and filter; voltage stabilizing didoe Z1 positive pole connects the base stage of triode Q3; capacitor C 32 and resistance R 38 are connected in parallel between triode Q3 base stage and emitter; the grounded emitter of triode Q3, the collector electrode of triode Q3 connects the sampling input of voltage sample feedback circuit.The collector electrode of triode Q3 connects 2 pin of optocoupler U2 in voltage sample feedback circuit specifically.
The beneficial effect that adopts technique scheme to produce is: the utility model is given voltage stabilizing didoe Z1 current limliting by resistance R 38; and utilize the sampled voltage of the conducting control voltage sample feedback circuit of triode Q3; thereby feed back to ON-OFF control circuit; reduce output voltage; play a protective role; when this protective circuit work, voltage stabilizing didoe can not damage, and trouble shooting can recover normal work automatically.
Accompanying drawing explanation
Fig. 1 is classical inverse exciting switching voltage regulator circuit theory diagrams;
Fig. 2 is the utility model switching power circuit schematic diagram;
Embodiment
Below in conjunction with accompanying drawing, utility model is described in further detail:
Be illustrated in figure 2 a kind of switching power circuit that utilizes this overvoltage type protective circuit, its structure comprises input and electromagnetic interference suppression circuit, current rectifying and wave filtering circuit, transformer change-over circuit, ON-OFF control circuit, output rectifier and filter, voltage sample feedback circuit, overvoltage crowbar, current rectifying and wave filtering circuit connects input and electromagnetic interference suppression circuit, the input of ON-OFF control circuit connection transformer change-over circuit, the output of output filter circuit connection transformer change-over circuit, voltage sample feedback circuit connects output rectifier and filter, overvoltage crowbar comprises voltage-stabiliser tube two utmost point Z1, capacitor C 32, resistance R 38, triode Q3, wherein voltage stabilizing didoe Z1 negative pole connects the anode of the output of output rectifier and filter, voltage stabilizing didoe Z1 positive pole connects the base stage of triode Q3, capacitor C 32 and resistance R 38 are connected in parallel between triode Q3 base stage and emitter, the grounded emitter of triode Q3, the collector electrode of triode Q3 connects 2 pin of optocoupler U2 in voltage sample feedback circuit.The control IC of ON-OFF control circuit is integrated circuit U1, and integrated circuit U1 has 6 pins, is respectively GND pin, FB pin, OPP/Latch pin, CS pin, Vcc pin, DRV pin.
Operation principle: raise when certain part failure of product causes output voltage; boosted voltage reaches the puncture voltage of voltage stabilizing didoe Z1; make voltage stabilizing didoe Z1 puncture conducting; do current limliting by resistance R 38; at this moment the base voltage of triode Q3 raises and then makes Q3 saturation conduction; make optocoupler U2 conducting; make the FB pin lower voltage of U1 turn duty ratio down; reduce output voltage; finally make under exceptional condition output voltage constant in the voltage slightly higher than normal output voltage, thereby arrive the function of overvoltage protection.Due to the current limliting of resistance R 38, the electric current of voltage stabilizing didoe Z1 is very little, makes it within electric current own bears, therefore when after the abnormal releasing of part failure, it is normal that product recovers, and do not need to change element.
Apply after the Switching Power Supply product failure of this new-type circuit, output voltage is clamped in safe voltage, can not cause terminal equipment to damage.This mode can not make voltage stabilizing didoe Z1 puncture short or open circuit, and when after trouble shooting, product can recover normal output automatically, working properly.Make circuit safer reliable.
Claims (2)
1. a Switching Power Supply output overvoltage protection circuit; it is characterized in that: overvoltage crowbar comprises voltage-stabiliser tube two utmost point Z1, capacitor C 32, resistance R 38, triode Q3; wherein voltage stabilizing didoe Z1 negative pole connects the anode of the output of output rectifier and filter; voltage stabilizing didoe Z1 positive pole connects the base stage of triode Q3; capacitor C 32 and resistance R 38 are connected in parallel between triode Q3 base stage and emitter; the grounded emitter of triode Q3, the collector electrode of triode Q3 connects the sampling input of voltage sample feedback circuit.
2. Switching Power Supply output overvoltage protection circuit according to claim 1, is characterized in that: the collector electrode of concrete triode Q3 connects 2 pin of optocoupler U2 in voltage sample feedback circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201320839086.8U CN203596738U (en) | 2013-12-19 | 2013-12-19 | Switch power supply output overvoltage protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201320839086.8U CN203596738U (en) | 2013-12-19 | 2013-12-19 | Switch power supply output overvoltage protection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203596738U true CN203596738U (en) | 2014-05-14 |
Family
ID=50677595
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201320839086.8U Expired - Fee Related CN203596738U (en) | 2013-12-19 | 2013-12-19 | Switch power supply output overvoltage protection circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN203596738U (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105071652A (en) * | 2015-09-22 | 2015-11-18 | 广东志高暖通设备股份有限公司 | Control Boost PFC circuit |
| CN105490514A (en) * | 2016-02-24 | 2016-04-13 | 航天长峰朝阳电源有限公司 | Secondary power supply anti-start-voltage-overshoot circuit |
| CN107658857A (en) * | 2017-09-21 | 2018-02-02 | 南京林洋电力科技有限公司 | A kind of switch power over-voltage protection circuit and method |
| CN112003241A (en) * | 2020-07-14 | 2020-11-27 | 宁波安信数控技术有限公司 | Overcurrent and overvoltage protection circuit for switching power supply |
-
2013
- 2013-12-19 CN CN201320839086.8U patent/CN203596738U/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105071652A (en) * | 2015-09-22 | 2015-11-18 | 广东志高暖通设备股份有限公司 | Control Boost PFC circuit |
| CN105071652B (en) * | 2015-09-22 | 2018-02-02 | 广东志高暖通设备股份有限公司 | One kind control Boost type pfc circuit |
| CN105490514A (en) * | 2016-02-24 | 2016-04-13 | 航天长峰朝阳电源有限公司 | Secondary power supply anti-start-voltage-overshoot circuit |
| CN107658857A (en) * | 2017-09-21 | 2018-02-02 | 南京林洋电力科技有限公司 | A kind of switch power over-voltage protection circuit and method |
| CN112003241A (en) * | 2020-07-14 | 2020-11-27 | 宁波安信数控技术有限公司 | Overcurrent and overvoltage protection circuit for switching power supply |
| CN112003241B (en) * | 2020-07-14 | 2022-11-11 | 宁波安信数控技术有限公司 | Overcurrent and overvoltage protection circuit for switching power supply |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103928909B (en) | The short-circuit protection method of Switching Power Supply fast and reliable and circuit | |
| CN102970791B (en) | Light-emitting diode (LED) constant current driving circuit and LED lamp | |
| CN202633914U (en) | Overvoltage protecting circuit of output electrolytic capacitor of active PFC (Power Factor Correction) circuit and switching power supply | |
| CN203596738U (en) | Switch power supply output overvoltage protection circuit | |
| CN203504280U (en) | Direct current power supply under-voltage automatic switching system based on microprocessor power supply monitor | |
| CN204361658U (en) | A kind of under-voltage protecting circuit | |
| CN103474965A (en) | Low-cost alternating-current input overvoltage protection circuit and switching power supply | |
| CN103607016A (en) | Non-polarity automatic judgment charging circuit and charger | |
| CN104218531A (en) | Short circuit protecting circuit and method | |
| CN205070392U (en) | Smart jack controller | |
| CN103346553A (en) | Reverse-connection-resisting and relay-coil-short-circuit-resisting control circuit of electronic controller | |
| CN203368003U (en) | Dual protection device for Boost circuit | |
| CN102612209B (en) | Recoverable protective circuit of boosting LED (light emitting diode) driving power supply and design method of recoverable protective circuit | |
| CN204732869U (en) | A kind of high reliability overvoltage surge protective circuit | |
| CN203398768U (en) | Low-cost AC input overvoltage protection circuit and switching power supply | |
| CN203491680U (en) | Automatic reset electric leakage overvoltage/undervoltage protection circuit | |
| CN203632222U (en) | Output short circuit protection circuit of flyback converter | |
| CN203368840U (en) | LED driving circuit and LED display device | |
| CN103692058B (en) | With the soft-start circuit of power factor correction circuit inverter type welder | |
| CN202797867U (en) | Short circuit protection circuit and power supply circuit provided with the same | |
| CN204205568U (en) | Switching Power Supply and short-circuit protection circuit thereof | |
| CN101877475B (en) | Power supply short-circuit protection circuit | |
| CN204068210U (en) | Short-circuit protection circuit | |
| CN203103926U (en) | Switching power supply and protective circuit thereof | |
| CN103401220B (en) | A kind of novel switched power supply short-circuit protective circuit and guard method thereof |
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: 20140514 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |