CN204668923U - Switch power over-voltage protection circuit - Google Patents
Switch power over-voltage protection circuit Download PDFInfo
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- CN204668923U CN204668923U CN201520345142.1U CN201520345142U CN204668923U CN 204668923 U CN204668923 U CN 204668923U CN 201520345142 U CN201520345142 U CN 201520345142U CN 204668923 U CN204668923 U CN 204668923U
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- 239000004065 semiconductor Substances 0.000 claims description 14
- 230000001681 protective effect Effects 0.000 description 2
- 230000002411 adverse Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
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Abstract
The utility model is specially a kind of switch power over-voltage protection circuit, solves the problem that the existing Switching Power Supply based on UC3842 does not possess input overvoltage protection.Switch power over-voltage protection circuit; comprise rectifier bridge Q, chip U1, transformer T, triode VT1 and one-way SCR VS; described rectifier bridge Q pin 1 is connected 220V alternating current two ends respectively with rectifier bridge Q pin 2; rectifier bridge Q pin 3 connects electric capacity C5, resistance R2, chip U1 pin 5, electric capacity C4 and resistance R9 respectively; the G pole of resistance R2 other end difference contact resistance R1, resistance R6 and one-way SCR VS, the resistance R1 other end connects rectifier bridge Q pin 4, the electric capacity C5 other end, resistance R10, electric capacity C7 and transformer T coil L1 etc. respectively.The voltage that the reference voltage source that the utility model switch power over-voltage protection circuit utilizes chip intrinsic provides and TL431 can form structure input switch power supply overvoltage protection circuit simple, with low cost, both guaranteed safely, have reduced costs, and turn reduced loss.
Description
Technical field
The utility model relates to protective circuit, is specially a kind of switch power over-voltage protection circuit.
Background technology
Meet the condition of normal instructions for use in electrical technology index under, work safely and reliably under adverse circumstances and catastrophic failure situation for making power supply, various kinds of protective circuit must be designed, such as prevent the energising moment current-limiting circuit of surge current and the soft starting circuit of output voltage overshoot and overvoltage, under-voltage, overcurrent, short-circuit protection circuit door etc., along with the development of electronic technology, there is the control chip of polytype Switching Power Supply, when forming DC/DC or AC/DC switch converters, UC3842 is the current-mode control chip released the earliest, be still PWM integrated manipulator most widely used at present.The current sense comparator that UC3842 self has; output overcurrent and short-circuit protection can be realized; its inner intrinsic input undervoltage lock-in circuit; also can realize input undervoltage protection easily, be therefore that Switching Power Supply that core is formed is easy to just to achieve output overcurrent or short-circuit protection and input undervoltage protection with UC3842.But based in the Switching Power Supply of UC3842; how to realize input overvoltage protection but also seldom to relate to; in fact this kind of power supply does not just possess input overvoltage protection; equipment is so just made to there is potential safety hazard; the harm that input overvoltage causes Switching Power Supply; be mainly manifested in device because the voltage that bears and current stress exceed the normal scope that uses and damaging, may can not meet the demands by electricity function index simultaneously.
Summary of the invention
The utility model does not possess the problem of input overvoltage protection in order to solve the existing Switching Power Supply based on UC3842, provide a kind of timing circuit module.
The utility model adopts following technical scheme to realize: switch power over-voltage protection circuit, comprise rectifier bridge Q, chip U1, transformer T, triode VT1 and one-way SCR VS, described rectifier bridge Q pin 1 is connected 220V alternating current two ends respectively with rectifier bridge Q pin 2, rectifier bridge Q pin 3 connects electric capacity C5 respectively, resistance R2, the K pole of one-way SCR VS, electric capacity C2, chip U1 pin 5, electric capacity C4 and resistance R9, the resistance R2 other end is contact resistance R1 respectively, the G pole of resistance R6 and one-way SCR VS, the resistance R1 other end connects rectifier bridge Q pin 4 respectively, the electric capacity C5 other end, resistance R10, electric capacity C7 and transformer T coil L1, the resistance R10 other end connects ground capacity C1 respectively, diode D1 negative pole and chip U1 pin 7, diode D2 positive pole connects grounded inductor L3, chip U1 pin 1 connects chip U1 pin 2 by electric capacity C3, chip U1 pin 8 is contact resistance R12 respectively, triode VT1 emitter and resistance R3, the resistance R3 other end is contact resistance R4 and triode VT1 base stage respectively, the resistance R4 other end connects the A pole of one-way SCR VS, triode VT1 collector electrode is the contact resistance R6 other end and resistance R5 respectively, the resistance R5 other end connects chip U1 pin 3 respectively, resistance R8 and the electric capacity C4 other end, the S pole of the resistance R8 other end difference contact resistance R9 other end and metal-oxide-semiconductor VR, the G pole of metal-oxide-semiconductor VR connects chip U1 pin 6 by resistance R7, D pole contact resistance R11 and the transformer T coil L1 other end respectively of metal-oxide-semiconductor VR, transformer T coil L2 two ends shunt capacitance C6 and output Uo.
Operation principle of the present utility model is: wherein resistance R6, chip U1 and triode VT1 forms input switch power supply overvoltage protection circuit, when input voltage exceedes set point, triode VT1 conducting will make the voltage of chip U1 pin 3 more than 1V, output driving pulse is blocked, metal-oxide-semiconductor VR is turned off, the voltage that metal-oxide-semiconductor VR is born is only input voltage, metal-oxide-semiconductor VR is protected, the direct voltage that the electric current flowing through metal-oxide-semiconductor VR is set up on sample resistance R9 is input to chip U1 pin 3, can limit metal-oxide-semiconductor VR peak current, thus realize output overcurrent or short-circuit protection.
The beneficial effects of the utility model are as follows: the voltage that the reference voltage source that the utility model switch power over-voltage protection circuit utilizes chip intrinsic provides and TL431 can form structure input switch power supply overvoltage protection circuit simple, with low cost; and be applied in the Switching Power Supply based on inverse-excitation converting; introduce input switch power supply overvoltage protection circuit; make when designing Switching Power Supply; withstand voltage relatively low switching tube can be selected; both guaranteed safely, reduce costs, turn reduce loss.
Accompanying drawing explanation
Fig. 1 is structural representation of the present utility model.
Embodiment
Switch power over-voltage protection circuit, comprises rectifier bridge Q, chip U1, transformer T, triode VT1 and one-way SCR VS, described rectifier bridge Q pin 1 is connected 220V alternating current two ends respectively with rectifier bridge Q pin 2, and rectifier bridge Q pin 3 connects electric capacity C5 respectively, resistance R2, the K pole of one-way SCR VS, electric capacity C2, chip U1 pin 5, electric capacity C4 and resistance R9, the resistance R2 other end is contact resistance R1 respectively, the G pole of resistance R6 and one-way SCR VS, the resistance R1 other end connects rectifier bridge Q pin 4 respectively, the electric capacity C5 other end, resistance R10, electric capacity C7 and transformer T coil L1, the resistance R10 other end connects ground capacity C1 respectively, diode D1 negative pole and chip U1 pin 7, diode D2 positive pole connect grounded inductor L3, and chip U1 pin 1 connects chip U1 pin 2, chip U1 pin 8 contact resistance R12 respectively by electric capacity C3, triode VT1 emitter and resistance R3, the resistance R3 other end is contact resistance R4 and triode VT1 base stage respectively, the resistance R4 other end connects the A pole of one-way SCR VS, and the triode VT1 collector electrode respectively contact resistance R6 other end and resistance R5, the resistance R5 other end connects chip U1 pin 3 respectively, resistance R8 and the electric capacity C4 other end, the S pole of the resistance R8 other end difference contact resistance R9 other end and metal-oxide-semiconductor VR, the G pole of metal-oxide-semiconductor VR connects chip U1 pin 6 by resistance R7, D pole contact resistance R11 and the transformer T coil L1 other end respectively of metal-oxide-semiconductor VR, transformer T coil L2 two ends shunt capacitance C6 and output Uo.
In specific implementation process, chip U1 is UC3842 chip, and one-way SCR VS is TL431.
Claims (2)
1. a switch power over-voltage protection circuit, comprises rectifier bridge Q, chip U1, transformer T, triode VT1 and one-way SCR VS, is characterized in that: described rectifier bridge Q pin 1 is connected 220V alternating current two ends respectively with rectifier bridge Q pin 2, and rectifier bridge Q pin 3 connects electric capacity C5 respectively, resistance R2, the K pole of one-way SCR VS, electric capacity C2, chip U1 pin 5, electric capacity C4 and resistance R9, the resistance R2 other end is contact resistance R1 respectively, the G pole of resistance R6 and one-way SCR VS, the resistance R1 other end connects rectifier bridge Q pin 4 respectively, the electric capacity C5 other end, resistance R10, electric capacity C7 and transformer T coil L1, the resistance R10 other end connects ground capacity C1 respectively, diode D1 negative pole and chip U1 pin 7, diode D2 positive pole connect grounded inductor L3, and chip U1 pin 1 connects chip U1 pin 2, chip U1 pin 8 contact resistance R12 respectively by electric capacity C3, triode VT1 emitter and resistance R3, the resistance R3 other end is contact resistance R4 and triode VT1 base stage respectively, the resistance R4 other end connects the A pole of one-way SCR VS, and the triode VT1 collector electrode respectively contact resistance R6 other end and resistance R5, the resistance R5 other end connects chip U1 pin 3 respectively, resistance R8 and the electric capacity C4 other end, the S pole of the resistance R8 other end difference contact resistance R9 other end and metal-oxide-semiconductor VR, the G pole of metal-oxide-semiconductor VR connects chip U1 pin 6 by resistance R7, D pole contact resistance R11 and the transformer T coil L1 other end respectively of metal-oxide-semiconductor VR, transformer T coil L2 two ends shunt capacitance C6 and output Uo.
2. switch power over-voltage protection circuit according to claim 1, is characterized in that: chip U1 is UC3842 chip, and one-way SCR VS is TL431.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520345142.1U CN204668923U (en) | 2015-05-26 | 2015-05-26 | Switch power over-voltage protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520345142.1U CN204668923U (en) | 2015-05-26 | 2015-05-26 | Switch power over-voltage protection circuit |
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| Publication Number | Publication Date |
|---|---|
| CN204668923U true CN204668923U (en) | 2015-09-23 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201520345142.1U Active CN204668923U (en) | 2015-05-26 | 2015-05-26 | Switch power over-voltage protection circuit |
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| CN (1) | CN204668923U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105656463A (en) * | 2016-04-05 | 2016-06-08 | 深圳市莱福德光电有限公司 | Protection circuit applied to super junction MOS (metal oxide semiconductor) |
| CN106851883A (en) * | 2016-12-28 | 2017-06-13 | 广东格兰仕集团有限公司 | A kind of soft starting circuit and its method for becoming micro-wave oven |
| CN107094338A (en) * | 2017-06-30 | 2017-08-25 | 湖州灵感电子科技有限公司 | A kind of constant current driver circuit for LED |
-
2015
- 2015-05-26 CN CN201520345142.1U patent/CN204668923U/en active Active
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105656463A (en) * | 2016-04-05 | 2016-06-08 | 深圳市莱福德光电有限公司 | Protection circuit applied to super junction MOS (metal oxide semiconductor) |
| CN105656463B (en) * | 2016-04-05 | 2023-08-15 | 深圳市莱福德光电有限公司 | Protection circuit for super-junction MOS application |
| CN106851883A (en) * | 2016-12-28 | 2017-06-13 | 广东格兰仕集团有限公司 | A kind of soft starting circuit and its method for becoming micro-wave oven |
| CN106851883B (en) * | 2016-12-28 | 2020-04-03 | 广东格兰仕集团有限公司 | Soft start circuit and method for variable frequency microwave oven |
| CN107094338A (en) * | 2017-06-30 | 2017-08-25 | 湖州灵感电子科技有限公司 | A kind of constant current driver circuit for LED |
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