CN201138747Y - Alternating current inputting over/under voltage protective circuit for switch power supply - Google Patents

Alternating current inputting over/under voltage protective circuit for switch power supply Download PDF

Info

Publication number
CN201138747Y
CN201138747Y CNU2008200000586U CN200820000058U CN201138747Y CN 201138747 Y CN201138747 Y CN 201138747Y CN U2008200000586 U CNU2008200000586 U CN U2008200000586U CN 200820000058 U CN200820000058 U CN 200820000058U CN 201138747 Y CN201138747 Y CN 201138747Y
Authority
CN
China
Prior art keywords
circuit
voltage
overvoltage
undervoltage
under
Prior art date
Application number
CNU2008200000586U
Other languages
Chinese (zh)
Inventor
朱俊高
Original Assignee
深圳晶辰电子科技股份有限公司
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by 深圳晶辰电子科技股份有限公司 filed Critical 深圳晶辰电子科技股份有限公司
Priority to CNU2008200000586U priority Critical patent/CN201138747Y/en
Application granted granted Critical
Publication of CN201138747Y publication Critical patent/CN201138747Y/en

Links

Abstract

The utility model discloses an overvoltage-undervoltage protection circuit of the alternating current input of switch power supply, which comprises an overvoltage-undervoltage detection circuit, an overvoltage-undervoltage comparison circuit, an overvoltage-undervoltage backlash circuit, a reversing circuit and a control circuit. The overvoltage-undervoltage protection circuit is characterized in that a voltage input terminal Va is connected with the input resistance of the overvoltage detection circuit R4 and the input resistance of the undervoltage detection circuit R12, the output terminal of the undervoltage detection circuit Vc is connected with R end of the undervoltage comparison circuit and a diode at one end of the undervoltage backlash circuit D6, and the resistance at the other end of the undervoltage backlash circuit R19 is connected with Ctrl; besides of connecting with the overvoltage backlash circuit and the R end of the overvoltage comparison circuit, the output terminal of the overvoltage detection circuit Vb is also connected with a diode D5 and the K end of the undervoltage comparison circuit, the output terminal of the overvoltage comparison circuit K is connected with the input resistance of the reversing circuit R8, the output terminal of the reversing circuit R9 is connected with the input terminal of the control circuit, and the output terminal of the control circuit is connected with the input resistance of the overvoltage backlash circuit R16 via a diode D7. The overvoltage-undervoltage protection circuit of the alternating current input of switch power supply has the advantages of the low cost, the low noise, the low loss and the high reliability.

Description

Switching Power Supply exchanges the input over under-voltage protection circuit
Technical field:
The utility model circuit belongs to over under-voltage protection circuit, is specially Switching Power Supply and exchanges the input over under-voltage protection circuit.
Background technology:
Exchanging the protection of input overvoltage/undervoltage is important defencive function part in the power supply, and each product all can exist, and particularly high-end communication power supply all has this function.When input voltage exceeded the trouble free service voltage of power supply, this circuit operation had guaranteed that power supply is not damaged.Simultaneously, added overvoltage/undervoltage return difference circuit, made protective circuit, guaranteed the reliability service of power supply not because of repeatedly action appears in voltage fluctuation.
Present protective circuit owing to used active device such as operational amplifier, makes this circuit must increase independent accessory power supply power supply and can realize function (it is called active protective circuit).The increase of accessory power supply at first causes the rising of cost, because necessary device such as transformer, inductance, electrochemical capacitor, rectifying tube will be arranged; Take certain space (space is especially valuable in the power supply of high power density especially), general 10W transformer is also wanted the volume of 25 * 50 * 15 (unit millimeters).Secondly, accessory power supply also is a Switching Power Supply, so, increases for whole power supply and disturb and electromagnetic radiation, causes Filtering Processing and radiation proof difficulty to strengthen.Moreover accessory power supply also has the device (as electrochemical capacitor, MOS etc.) in complicated control and certain life-span, so, will increase the probability of control failure greatly, thereby has reduced the reliability of whole power-supply system.At last, it has certain loss to reduce the efficient (the existing input over under-voltage protection circuit that exchanges is referring to accompanying drawing 2) of whole power supply.
Summary of the invention:
The purpose of this utility model is to provide a kind of " Switching Power Supply exchanges the input over under-voltage protection circuit " of adopting the passive protection circuit.This protective circuit is by over-voltage detection circuit, undervoltage detection circuit, overvoltage comparison circuit, under-voltage comparison circuit, and overvoltage return difference circuit, under-voltage return difference circuit, negater circuit and control circuit are formed.Wherein, over-voltage detection circuit is made up of series resistance R4, resistance R 5, resistance R 14 and filter capacitor C3; Undervoltage detection circuit is made up of series resistance R12, resistance R 11, resistance R 18 and capacitor C 5; Overvoltage comparison circuit and under-voltage comparison circuit adopt integrated circuit (ICS); Negater circuit is made up of transistor Q5 and resistance R 8, resistance R 9; Overvoltage return difference circuit is made up of resistance R 15 and transistor Q6; Under-voltage return difference circuit is made of resistance R 19 and diode D6 serial connection; Control circuit selects for use N-channel MOS pipe Q4 to realize.
This Switching Power Supply exchanges the input over under-voltage protection circuit and has low cost, low noise, and low-loss, advantages such as high reliability also are applicable in the power supply of DC input voitage.
Description of drawings:
Fig. 1 is that Switching Power Supply exchanges input over under-voltage protection circuit schematic diagram.
Fig. 2 is the existing input over under-voltage protection circuit schematic diagram that exchanges.
Embodiment:
Referring to Fig. 1, the utility model is that Switching Power Supply exchanges the input over under-voltage protection circuit, comprise over-voltage detection circuit, undervoltage detection circuit, overvoltage comparison circuit, under-voltage comparison circuit, overvoltage return difference circuit, under-voltage return difference circuit, negater circuit and control circuit, it is characterized in that: the Va voltage input end is connected with undervoltage detection circuit input resistance R12 with over-voltage detection circuit input resistance R4, undervoltage detection circuit output Vc is connected with under-voltage return difference circuit one end diode D6 with under-voltage comparison circuit R end, under-voltage return difference circuit other end resistance R 19 connects Ctrl, and (Ctrl refers to the shut down function end of Be Controlled PWM chip, be connected with metal-oxide-semiconductor Q4 drain electrode, close output when this circuit is metal-oxide-semiconductor Q4 conducting, for example 1 pin of UC3843 just can be the Ctrl pin); Over-voltage detection circuit output Vb is except that with overvoltage return difference circuit and overvoltage comparison circuit R end is connected, also link to each other with under-voltage comparison circuit K end through diode D5, overvoltage comparison circuit output K is connected with negater circuit input resistance R8, negater circuit output resistance R 9 is connected with control circuit input (metal-oxide-semiconductor Q4 grid), control circuit output (metal-oxide-semiconductor Q4 drain electrode) links to each other with overvoltage return difference circuit input resistance R16 through diode D7, and the control circuit output connects resistance R 19 1 ends in the under-voltage return difference circuit simultaneously.
The course of work is as follows: when (referring to Fig. 1) surpasses maximum operating voltage point when AC-input voltage, over-voltage detection circuit work, the voltage (Vb) at resistance R 14 two ends surpasses 2.5V, then the K of overvoltage comparison circuit ICS2 end becomes electronegative potential (about 2.5V) by high potential, this moment, diode ZD2 was not breakdown, not conducting of transistor Q5, the output high level, make metal-oxide-semiconductor Q4 conducting, on the one hand control end voltage is dragged down, control PWM chip IC 1 (PWM is meant the english abbreviation of arteries and veins money modulation, is that UC3843 is exactly the PWM cake core as IC1) no-output, metal-oxide-semiconductor Q4 conducting on the other hand, after overvoltage protection action, the driving of transistor Q6 by diode D7 clamper and by, then resistance R 15 open circuit can not be in parallel with resistance R 14, makes that the Vb point voltage is higher, when voltage was low to moderate under the pressure point certain when a bit, after test point Vb voltage is lower than 2.5V, control IC 1 resume work again (difference of crossing pressure point and recovery point voltage is exactly the overvoltage return difference, and the return difference value is by resistance R 15 adjustings); When AC-input voltage is lower than minimum operating voltage point; the work of under-voltage protection testing circuit; the voltage (Vc) at resistance R 18 two ends is lower than 2.5V; under-voltage comparison circuit action; the K end of integrated circuit (IC) 2 becomes high potential by electronegative potential; D5 sends into overvoltage comparison circuit by diode, makes its chain reaction work according to above overvoltage protection, closes the output of PWM chip IC 1.
The operation principle of overvoltage return difference circuit, before overvoltage protection, because not conducting of transistor Q4, the then saturated and conducting of resistance R 6 driving transistors Q6, it is in parallel with resistance R 14 to form resistance R 15; After the overvoltage protection action, the driving of transistor Q6 by diode D7 clamper and by, then resistance R 15 open circuits can not be in parallel with resistance R 14.
The operation principle of under-voltage return difference circuit, before under-voltage protection, not conducting of metal-oxide-semiconductor Q4, then diode D6, resistance R 19 are in vacant state, do not seal in the loop, and then under-voltage sampling point magnitude of voltage (Vc) is the terminal voltage at the two ends of resistance R 18.After under-voltage protection; transistor Q4 conducting; diode D6 connects back with resistance R 19 and resistance R 18 constitutes relation in parallel; make that under-voltage test point voltage is lower; when voltage is higher than on the under-voltage protection point voltage certain when a bit; after test point Vc voltage is higher than 2.5V, control chip IC1 resume work again (difference of under-voltage point and recovery point voltage is exactly under-voltage return difference, and the return difference value is regulated by R19).
Vinh is an over-voltage protection point in the accompanying drawing, and Vinl is the under-voltage protection point, and V is a hysteresis voltage, and HV is the voltage of input AC behind bridge rectifier, and Va is the detection voltage after the interchange full-wave rectification, and Vb is that overvoltage detects voltage, and Vc is under-voltage detection voltage.
This circuit compare with traditional circuit cost not enough its 1/4, volume is not enough its 1/5, loss is not enough its 1/3 owing to adopt benchmaring overvoltage/undervoltage point, so the precision aspect is at all no less than traditional circuit.(benchmark is a kind of of pressurizer, and reference voltage is fixing 2.5V because of, novel circuit all adopts low energy-consumption electronic devices such as resistance, benchmark, triode again.Benchmark 431 is types of pressurizer, full name be similar models such as AZ431 or TL431 all can), save auxiliary power supply, increased reliability, simultaneously, reduced interference and radiation again.Have very high economic benefit and high reliability.

Claims (1)

1. a Switching Power Supply exchanges the input over under-voltage protection circuit, comprise over-voltage detection circuit, undervoltage detection circuit, overvoltage comparison circuit, under-voltage comparison circuit, overvoltage return difference circuit, under-voltage return difference circuit, negater circuit and control circuit, it is characterized in that: the Va voltage input end is connected with undervoltage detection circuit input resistance R12 with over-voltage detection circuit input resistance R4, undervoltage detection circuit output Vc is connected with under-voltage return difference circuit one end diode D6 with under-voltage comparison circuit R end, and under-voltage return difference circuit other end resistance R 19 connects Ctrl (metal-oxide-semiconductor Q4 drain electrode); Over-voltage detection circuit output Vb is except that with overvoltage return difference circuit and overvoltage comparison circuit R end is connected, also link to each other with under-voltage comparison circuit K end through diode D5, overvoltage comparison circuit output K is connected with negater circuit input resistance R8, negater circuit output resistance R 9 is connected with control circuit input metal-oxide-semiconductor Q4 grid, and control circuit output metal-oxide-semiconductor Q4 drain electrode links to each other with overvoltage return difference circuit input resistance R16 through diode D7.
CNU2008200000586U 2008-01-04 2008-01-04 Alternating current inputting over/under voltage protective circuit for switch power supply CN201138747Y (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CNU2008200000586U CN201138747Y (en) 2008-01-04 2008-01-04 Alternating current inputting over/under voltage protective circuit for switch power supply

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CNU2008200000586U CN201138747Y (en) 2008-01-04 2008-01-04 Alternating current inputting over/under voltage protective circuit for switch power supply

Publications (1)

Publication Number Publication Date
CN201138747Y true CN201138747Y (en) 2008-10-22

Family

ID=40039427

Family Applications (1)

Application Number Title Priority Date Filing Date
CNU2008200000586U CN201138747Y (en) 2008-01-04 2008-01-04 Alternating current inputting over/under voltage protective circuit for switch power supply

Country Status (1)

Country Link
CN (1) CN201138747Y (en)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102035169A (en) * 2009-09-28 2011-04-27 研祥智能科技股份有限公司 Input overvoltage protection circuit and DC-DC power supply conversion device
CN102280860A (en) * 2011-05-19 2011-12-14 河海大学常州校区 PWM (Pulse Width Modulation) chip-based input overvoltage protection circuit of auto-excitation type converter
CN103166197A (en) * 2011-12-17 2013-06-19 西安恒飞电子科技有限公司 Input over-current protection circuit of communication power supply module
CN103458342A (en) * 2013-09-18 2013-12-18 上海贝岭股份有限公司 Circuit eliminating shutdown POP sound of audio power amplifier
WO2015051688A1 (en) * 2013-10-09 2015-04-16 珠海格力电器股份有限公司 Protective circuit for input voltage of switch power source
CN104538936A (en) * 2014-12-12 2015-04-22 广州金升阳科技有限公司 Input overvoltage protection circuit of switching power supply
CN104836419A (en) * 2015-05-25 2015-08-12 无锡安邦电气有限公司 Switching power supply driver chip supply circuit with undervoltage detection function
CN107449959A (en) * 2017-07-25 2017-12-08 郑州瑞能电源技术有限公司 Input over under-voltage protection circuit
CN108521115A (en) * 2018-03-14 2018-09-11 苏州博创集成电路设计有限公司 A kind of primary controller and Switching Power Supply of Switching Power Supply

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102035169B (en) * 2009-09-28 2015-05-20 研祥智能科技股份有限公司 Input overvoltage protection circuit and DC-DC power supply conversion device
CN102035169A (en) * 2009-09-28 2011-04-27 研祥智能科技股份有限公司 Input overvoltage protection circuit and DC-DC power supply conversion device
CN102280860B (en) * 2011-05-19 2014-06-25 河海大学常州校区 PWM (Pulse Width Modulation) chip-based input overvoltage protection circuit of auto-excitation type converter
CN102280860A (en) * 2011-05-19 2011-12-14 河海大学常州校区 PWM (Pulse Width Modulation) chip-based input overvoltage protection circuit of auto-excitation type converter
CN103166197A (en) * 2011-12-17 2013-06-19 西安恒飞电子科技有限公司 Input over-current protection circuit of communication power supply module
CN103458342A (en) * 2013-09-18 2013-12-18 上海贝岭股份有限公司 Circuit eliminating shutdown POP sound of audio power amplifier
WO2015051688A1 (en) * 2013-10-09 2015-04-16 珠海格力电器股份有限公司 Protective circuit for input voltage of switch power source
CN104577993B (en) * 2013-10-09 2018-11-09 珠海格力电器股份有限公司 Switching Power Supply input voltage protection circuit
CN104577993A (en) * 2013-10-09 2015-04-29 珠海格力电器股份有限公司 Input voltage protection circuit of switching power supply
CN104538936A (en) * 2014-12-12 2015-04-22 广州金升阳科技有限公司 Input overvoltage protection circuit of switching power supply
CN104836419A (en) * 2015-05-25 2015-08-12 无锡安邦电气有限公司 Switching power supply driver chip supply circuit with undervoltage detection function
CN104836419B (en) * 2015-05-25 2017-05-31 无锡安邦电气有限公司 Switching Power Supply driving chip power supply circuit with under-voltage detection function
CN107449959A (en) * 2017-07-25 2017-12-08 郑州瑞能电源技术有限公司 Input over under-voltage protection circuit
CN108521115A (en) * 2018-03-14 2018-09-11 苏州博创集成电路设计有限公司 A kind of primary controller and Switching Power Supply of Switching Power Supply
CN108521115B (en) * 2018-03-14 2019-10-29 苏州博创集成电路设计有限公司 A kind of primary controller and Switching Power Supply of Switching Power Supply

Similar Documents

Publication Publication Date Title
CN204030996U (en) A kind of reverse exciting switching voltage regulator circuit
CN202004651U (en) Switching power supply circuit for flyback structure
CN201243203Y (en) Safety protection device for electric appliance
CN103219878B (en) A kind of capacitor discharging circuit and power inverter
CN203690884U (en) Overvoltage protection circuit, driver and power supply comprising the same
US20160211769A1 (en) Self-excited push-pull converter
CN101707828B (en) Constant-current source driving circuit with open circuit protection and adopting LED
CN101572485A (en) Intelligent driving control method and device for secondary synchronous rectifier
CN105939122A (en) Switching power supply device
CN102256087B (en) A kind of low-power consumption standby circuit and television set
CN203398990U (en) Self-protection integrated circuit and power supply system
CN103378725B (en) There is controller and the switching controller of multifunctional pin
CN202373957U (en) Over-voltage and under-voltage protection circuit
US8358517B2 (en) Switching power conversion circuit and power supply using same
CN101867168A (en) Power protecting circuit and LED lamp
CN203289341U (en) Flyback switch power supply circuit
CN101145699A (en) Power supply system and method for controlling output voltage
CN203180783U (en) Boosted circuit
CN103887984A (en) Isolating converter and switching power supply comprising same
CN103326325B (en) Switching Power Supply output short-circuit and under-voltage protecting circuit
CN101841149A (en) Power source protection circuit and LED lamp
CN207926438U (en) DC power supply
CN102412720A (en) Switching power circuit and power factor correction (PFC) control circuit thereof
CN100550587C (en) The synchronous rectification of the variable turn ratio or diode rectification converter
CN201063055Y (en) Circuit for monitoring three-phase four-wire power failure

Legal Events

Date Code Title Description
C14 Grant of patent or utility model
GR01 Patent grant
C17 Cessation of patent right
CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20081022

Termination date: 20120104