CN103715660B - Overvoltage protection circuit and method for switching power supply with output voltages adjustable - Google Patents
Overvoltage protection circuit and method for switching power supply with output voltages adjustable Download PDFInfo
- Publication number
- CN103715660B CN103715660B CN201410018881.XA CN201410018881A CN103715660B CN 103715660 B CN103715660 B CN 103715660B CN 201410018881 A CN201410018881 A CN 201410018881A CN 103715660 B CN103715660 B CN 103715660B
- Authority
- CN
- China
- Prior art keywords
- resistance
- poles
- reference source
- pin
- shunt reference
- 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
- 238000000034 method Methods 0.000 title claims abstract description 13
- 230000005611 electricity Effects 0.000 claims description 5
- 101100496158 Arabidopsis thaliana CLF gene Proteins 0.000 claims description 4
- 102220090095 rs1042713 Human genes 0.000 claims description 3
- 102220112179 rs3743602 Human genes 0.000 claims description 3
- 102220123496 rs557896607 Human genes 0.000 claims description 3
- 206010034133 Pathogen resistance Diseases 0.000 claims description 2
- 230000005622 photoelectricity Effects 0.000 claims description 2
- 238000010586 diagram Methods 0.000 description 5
- 208000031361 Hiccup Diseases 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
- 239000003381 stabilizer Substances 0.000 description 1
Landscapes
- Emergency Protection Circuit Devices (AREA)
- Direct Current Feeding And Distribution (AREA)
Abstract
Provided are an overvoltage protection circuit and method for a switching power supply with output voltages adjustable. When the output voltages need to be adjustable within a small range, a 12V output power supply needs to normally work between 8.4V and 15.6V. The overvoltage protection circuit for the switching power supply with the output voltages adjustable is composed of an on-off control circuit and an overvoltage protection circuit body, the on-off control circuit comprises a control IC and a secondary feedback loop related to the control IC, the overvoltage protection circuit body comprises a three-end adjustable shunt reference source U8, and the three-end adjustable shunt reference source U8 is connected with a photoelectric coupler U2 and a three-end adjustable shunt reference source U9. The overvoltage protection circuit and method are used for overvoltage protection circuits.
Description
Technical field：
The present invention relates to a kind of overvoltage crowbar of Switching Power Supply that can adjust of output voltage and guard method.
Background technology：
Traditional switch power supply line structure be input and electromagnetic interface filter, current rectifying and wave filtering circuit, pfc circuit (optional),
DC/DC translation circuits, output rectifier and filter, feedback loop, overvoltage crowbar, current foldback circuit.
Its operation principle is because failure or certain reason cause output voltage to be increased to voltage-stabiliser tube when Switching Power Supply
After the breakdown voltage of D100, optocoupler begins with electric current and flows through 3,4 pin, the 3 pin OPP/Latch voltages of control chip NCP1250
Raise, make NCP1250 locked, make chip stop output, so as to power supply is not also exported, reach the purpose of protection.
There is following defect in above-mentioned traditional overvoltage crowbar：
1) output voltage need small range can timing, such as 12V output power supply, needs can in 8.4V～15.6V
During normal work, such as cross pressure point and be generally located on 110%～130%UOUT, such as normal pressure point of crossing exists during 8.4V outputs
9.24～10.92V, but according to traditional overvoltage protection mode, when output voltage is adjusted to 12V, the output of power supply is already
Jing is protected, substantially cannot normal work.
2) in conventional power source solution, solve the above problems can be according to maximum output voltage 110%～
130% arranged pressure point, that is, the 110%～130% of 15.6V, but, when output voltage is in 8.4V, due to crossing pressure point
It is too high and design requirement cannot be met.
The content of the invention：
It is an object of the invention to provide the Switching Power Supply that a kind of output voltage can be adjusted with small range provides high-precision mistake
Voltage protection circuit and guard method
Above-mentioned purpose is realized by following technical scheme：
A kind of overvoltage crowbar of the Switching Power Supply that output voltage can be adjusted, its composition include ON-OFF control circuit with
Overvoltage crowbar, the ON-OFF control circuit includes control IC and associated secondary side feedback loop, it is characterized in that：It is described
Overvoltage crowbar include three end adjustable shunt reference source U8, it is adjustable that described three ends adjustable shunt reference source U8 connect three ends
Shunt reference source U2 and three end adjustable shunt reference source U9；Three described end adjustable shunt reference source U8 have R poles, K poles and A
Parallel resistance between adjustable resistance R1001 in parallel between pole, described R poles and described A poles, described R poles and described K poles
R1002, resistance R1006 connect the bias voltage obtained on 12V output voltages or secondary VCC, and described K poles pass through resistance
R1008 is connected between the divider resistance of conventional overvoltage protection, and described K poles are connected to conventional master by resistance R1007
In the reference of voltage loop；Described overvoltage crowbar also includes three end adjustable shunt reference source U9 and photoelectrical coupler U7A,
1 pin of described photoelectrical coupler U7A is the positive pole of luminous tube, 2 pin be negative pole, 3 pin be emitter stage, 4 pin be colelctor electrode；It is described
1 pin of photoelectrical coupler U7A 12V+ is connect by resistance R29,2 pin of described photoelectrical coupler U7A connect three end adjustable shunts
The K poles of a reference source U9,3 pin of described photoelectrical coupler U7A connect 3 pin of control ICU1, and 3 pin of described control ICU1 lead to again
Cross resistance R25 and be connected to former limit ground, 4 pin of described photoelectrical coupler U7A are connected to former limit VCC, three described ends by resistance R26
The K poles of adjustable shunt reference source U9 are connected on 2 pin of photoelectrical coupler U7A, and the A of three described end adjustable shunt reference source U9 is extremely straight
Secondary ground is connected to, the divider resistance R1005 in parallel between described 12V+ and OVP_REF, lower divider resistance is
R1003 and R1004 is in parallel, and one end in parallel connects the R poles and OVP_REF ends of three end adjustable shunt reference source U9, the other end
Connect the A poles of three end adjustable shunt reference source U9.
The overvoltage crowbar of the Switching Power Supply that described output voltage can be adjusted, described overvoltage crowbar is also wrapped
Include three end adjustable shunt reference source U2 and photoelectrical coupler U6A, 1 pin of described photoelectrical coupler U6A for luminous tube positive pole,
2 pin are negative pole, and 1 pin of photoelectrical coupler U6A meets 12V+ by resistance R14, and 2 pin of described photoelectrical coupler U6A connect three ends
The K poles of adjustable shunt reference source U2, the A poles of three described end adjustable shunt reference source U2 connect secondary ground, in described 12V+ and
A upper divider resistance R16 in parallel between LOOP_REF, lower divider resistance is that R18 and R19 is in parallel, and one end in parallel connects three ends
The R poles and LOOP_REF ends of adjustable shunt reference source U2, the other end connects the A poles of three end adjustable shunt reference source U9.
The guard method of the overvoltage crowbar of the Switching Power Supply that described output voltage can be adjusted, in adjustment output electricity
When pressure, only adjustment adjustable resistance R1001, output voltage required magnitude of voltage is adjusted to, and crosses pressure point simultaneously in adjustment；
Design calculation process is as follows：
K pole tension (the units of three end adjustable shunt reference source U8：V)：
If simultaneously R1004 is R1003：
If simultaneously R19 is R18：
Output voltage is (unit：V)：
The over-voltage protection point of output voltage is (unit：V)：
During above-mentioned design is calculated, it is 2.5V directly to take three end adjustable shunt reference voltages；
When resistance R16, R18, R19, R1005, R1003, R1004, R1006, R1007, R1008 and R1002 are definite value, change
When becoming the resistance of R1001, output voltage and output voltage over-voltage protection point also can change into change with R1001, reach defeated
Go out voltage adjustable, output voltage over-voltage protection point is adjustable therewith；
Wherein R16=18Kohm, R18=NC, R19=4.6Kohm, R1005=22Kohm, R1003=4.7Kohm,
R1004=NC, R1006=4.7Kohm, R1007=4.7Kohm, R1008=4.7Kohm, R1002=4.7Kohm.
Beneficial effect：
1. the present invention can be used in all of power topology of Switching Power Supply, such as normal shock, flyback, half-bridge and full-bridge
Deng；The overvoltage crowbar of the Switching Power Supply that the output voltage that can be used in the Switching Power Supply of multiple-channel output can be adjusted, fits
Wide with scope, small range adjusts overvoltage, and protected effect is good.
2. the present invention improves overvoltage protection precision, solve client pressure point is crossed due to the regulation of output voltage can not be with
With the pain spot for adjusting.
Description of the drawings：
Accompanying drawing 1 is the circuit connection diagram of this product.
Accompanying drawing 2 is the circuit diagram of three end adjustable shunt reference source U8 in accompanying drawing 1.
Accompanying drawing 3 is the circuit diagram of three end adjustable shunt reference source U9 in accompanying drawing 1.
Accompanying drawing 4 is the circuit diagram of three end adjustable shunt reference source U2 in accompanying drawing 1.
There is annexation between same-sign in circuit diagram.
Specific embodiment：
Embodiment 1：
A kind of overvoltage crowbar of the Switching Power Supply that output voltage can be adjusted, its composition include ON-OFF control circuit with
Overvoltage crowbar, the ON-OFF control circuit includes control IC and associated secondary side feedback loop, described overvoltage guarantor
Protection circuit includes that three end adjustable shunt reference source U8, three described end adjustable shunt reference source U8 connect three end adjustable shunt benchmark
Source U2 and three end adjustable shunt reference source U9, three described end adjustable shunt reference source U8, model TL431, three described ends can
Adjust shunt reference source U8 that there is R levels, K levels and A levels, adjustable resistance R1001 in parallel between described R levels and described A levels is described
R levels and described K levels between parallel resistance R1002, obtain inclined on resistance R1006 connection 12V output voltages or secondary VCC
Voltage is put, described K levels are connected between the divider resistance of conventional overvoltage protection by described resistance R1008, described K
Level is connected in the reference of conventional principal voltage loop by described resistance R1007.
Described overvoltage crowbar is the conventional pair for being constituted with three end adjustable shunt reference sources and divider resistance
Side overvoltage crowbar and design.
Described overvoltage crowbar changes the electric current of the divider resistance of conventional voltage loop so as to realize output voltage
Adjustable purpose is the conventional secondary voltage loop circuit for being constituted with three end adjustable shunt reference sources and divider resistance.
Three end adjustable shunt reference source adopts TL431 chips, photoelectrical coupler to adopt LTV817.
Embodiment 2：
The overvoltage crowbar of the Switching Power Supply that the output voltage described in embodiment 1 can be adjusted, described adjustable resistance
High accuracy potentiometer or precision resister or the described adjustable resistance resistance more than described adjustable resistance in parallel are can also be,
Obtain bias voltage on described secondary VCC to be 12V voltages or be directly connected on output voltage Vo.
Embodiment 3：
The overvoltage crowbar of the Switching Power Supply that the output voltage described in embodiment 1 or 2 can be adjusted, described overvoltage guarantor
Protection circuit also includes photoelectrical coupler U7A, and 1 pin of described photoelectrical coupler U7A is the positive pole of luminous tube, 2 pin are negative
Pole, 3 pin are emitter stage, 4 pin are colelctor electrode；1 pin of described photoelectrical coupler U7A connects 12V+, described light by resistance R29
2 pin of electric coupler U7A connect the K pin of three end adjustable shunt reference source U9 (i.e. TL431), 3 pin of described photoelectrical coupler U7A
3 pin of control IC (model NCP1250) U1 are connect, 3 pin of described U1 are connected to former limit ground, described photoelectricity by resistance R25 again
4 pin of coupler U7A are connected to former limit VCC by resistance R26.
Embodiment 4：
The overvoltage crowbar of the Switching Power Supply that the output voltage described in embodiment 1 or 2 can be adjusted, described overvoltage guarantor
Protection circuit also includes three end adjustable shunt reference source U9, and the A poles of three described end adjustable shunt reference source U9 are directly connected to secondary
Ground, the divider resistance R1005 networks in parallel between described 12V+ and OVP_REF, lower divider resistance be R1003 and
R1004 is in parallel, and the intermediate point OVP_REF of divider resistance R1004 is connected to the R poles of three described end adjustable shunt reference source U9, institute
The K poles of the three end adjustable shunt reference source U9 for stating are connected on 2 pin of photoelectrical coupler U7A.
Embodiment 5：
The guard method of the overvoltage crowbar of the Switching Power Supply that a kind of output voltage can be adjusted, in adjustment output voltage
When, only adjustment adjustable resistance R1001 is adjusted to required magnitude of voltage output voltage, crosses pressure point simultaneously in adjustment；
Design calculation process is as follows：
The K pin voltage (units of U8：V)：
If simultaneously R1004 is R1003：
If simultaneously R19 is R18：
Output voltage is (unit：V)：
The over-voltage protection point of output voltage is (unit：V)：
In above-mentioned design calculating formula, it is 2.5V directly to take three end adjustable shunt reference voltages；
When R16, R18, R19, R1005, R1003, R1004, R1006, R1007, R1008 and R1002 are definite value, change
During the resistance of R1001, output voltage and output voltage over-voltage protection point also can change into change with R1001, reach output
Voltage is adjustable, and output voltage over-voltage protection point is adjustable therewith；Three end adjustable shunt reference source U2 connection R18, R18 parallel connection R19,
R19 connects R16；
R16=18Kohm, R18=NC, R19=4.6Kohm, R1005=22Kohm, R1003=4.7Kohm, R1004=
NC, R1006=4.7Kohm, R1007=4.7Kohm, R1008=4.7Kohm, R1002=4.7Kohm.
Embodiment 6：
The guard method of the overvoltage crowbar of the Switching Power Supply that the output voltage described in embodiment 5 can be adjusted, its electricity
One TL431 of route, an adjustable resistance and four resistance are constituted.With TL431 as core, between R the and A levels of TL431 and one
Individual adjustable resistance, between K levels and R levels and a resistance, K levels again by a resistance be connected to 12V export or secondary VCC on
Bias voltage is obtained, in addition K levels are connected between the divider resistance of traditional overvoltage protection again by a resistance, and K levels are led to again
Cross a resistance to be connected in the reference of traditional principal voltage loop, the circuit is built upon traditional secondary side feedback loop and biography
On the basis of the overvoltage crowbar of system.
Traditional secondary side feedback loop, including the indirect resistor voltage divider network that output is just negative with output, partial pressure
The intermediate point of resistor network is connected on the R poles of three end adjustable shunt reference sources, usually, in order to improve the precision of output voltage, point
The lower divider resistance of piezoresistance network is generally two resistor coupled in parallel, the A of three end adjustable shunt reference sources, in parallel between K poles
Feedback compensation network in parallel with an electric capacity again after individual resistance and capacitances in series, the K poles connection of three end adjustable shunt reference sources
In 2 pin of photoelectrical coupler, 1 pin of photoelectrical coupler is connected on the network before outputting inductance by a resistance and obtains work
Make electric current, 3 pin of photoelectrical coupler are connected on the ground of primary-side-control chip, and the pin of pin 4 of photoelectrical coupler is connected on the FB of control chip
Pin.
Traditional overvoltage crowbar includes divider resistance and three end adjustable shunt reference sources all the way, wherein partial pressure electricity
Resistance is connected between the positive pole of 12V voltage output ends and negative pole, and the intermediate point of divider resistance is connected on three end adjustable shunt reference sources
R poles, the K poles of three end adjustable shunt reference sources are connected on 2 pin of photoelectrical coupler, and 1 pin of photoelectrical coupler passes through again an electricity
Resistance is connected in 12V outputs.
Embodiment 7：
The overvoltage crowbar of the Switching Power Supply that the output voltage described in above-described embodiment can be adjusted, it is crossed pressure point and follows
Output voltage is adjustable together, easily realizes that pressure point met design requirement precision, when Switching Power Supply is adjusted within the limits prescribed,
Cross pressure point and also follow in the range of output voltage specifies (such as 110%～130% output voltage), its circuit is by one
TL431, an adjustable resistance and four resistance are constituted.With TL431 as core, between R the and A levels of TL431 and an adjustable electric
Resistance, between K levels and R levels and a resistance, K levels are connected to acquirement on 12V output voltages or secondary VCC by a resistance again
Bias voltage, in addition K levels be connected between the divider resistance of overvoltage protection by a resistance again, K levels again pass through a resistance
It is connected in the reference of major loop.Embodiment improves overvoltage protection precision, solves client due to the regulation of output voltage
And crossing pressure point can not follow the pain spot of regulation, when Switching Power Supply product failure or for some reason after overvoltage, Switching Power Supply
Can be with locked, can have the hiccups can also be clamped on a certain level output voltage.
Claims (3)
1. a kind of overvoltage crowbar of the Switching Power Supply that output voltage can be adjusted, its composition includes ON-OFF control circuit and mistake
Voltage protection circuit, the ON-OFF control circuit includes control IC and associated secondary side feedback loop, it is characterized in that：Described
Overvoltage crowbar includes three end adjustable shunt reference source U8, three described end adjustable point of three ends of adjustable shunt reference source U8 connections
Stream a reference source U2 and three end adjustable shunt reference source U9；Three described end adjustable shunt reference source U8 have R poles, K poles and A poles,
Parallel resistance between adjustable resistance R1001 in parallel between described R poles and described A poles, described R poles and described K poles
R1002, resistance R1006 connect the bias voltage obtained on 12V output voltages or secondary VCC, and described K poles pass through resistance
R1008 is connected between the divider resistance of conventional overvoltage protection, and described K poles are connected to conventional master by resistance R1007
In the reference of voltage loop；Described overvoltage crowbar also includes three end adjustable shunt reference source U9 and photoelectrical coupler U7A,
1 pin of described photoelectrical coupler U7A is the positive pole of luminous tube, 2 pin be negative pole, 3 pin be emitter stage, 4 pin be colelctor electrode；It is described
1 pin of photoelectrical coupler U7A 12V+ is connect by resistance R29,2 pin of described photoelectrical coupler U7A connect three end adjustable shunts
The K poles of a reference source U9,3 pin of described photoelectrical coupler U7A connect 3 pin of control ICU1, and 3 pin of described control ICU1 lead to again
Cross resistance R25 and be connected to former limit ground, 4 pin of described photoelectrical coupler U7A are connected to former limit VCC, three described ends by resistance R26
The K poles of adjustable shunt reference source U9 are connected on 2 pin of photoelectrical coupler U7A, and the A of three described end adjustable shunt reference source U9 is extremely straight
Secondary ground is connected to, the divider resistance R1005 in parallel between described 12V+ and OVP_REF, lower divider resistance is
R1003 and R1004 is in parallel, and one end in parallel connects the R poles and OVP_REF ends of three end adjustable shunt reference source U9, the other end
Connect the A poles of three end adjustable shunt reference source U9.
2. the overvoltage crowbar of the Switching Power Supply that output voltage according to claim 1 can be adjusted, is characterized in that：Institute
The overvoltage crowbar stated also includes three end adjustable shunt reference source U2 and photoelectrical coupler U6A, described photoelectrical coupler U6A
1 pin be the positive pole of luminous tube, 2 pin be negative pole, 1 pin of photoelectrical coupler U6A connects 12V+, described photoelectricity by resistance R14
2 pin of coupler U6A connect the K poles of three end adjustable shunt reference source U2, and the A poles of three described end adjustable shunt reference source U2 connect pair
Bian Di, the divider resistance R16 in parallel between described 12V+ and LOOP_REF, lower divider resistance be R18 and R19 simultaneously
Connection, one end in parallel connects the R poles and LOOP_REF ends of three end adjustable shunt reference source U2, adjustable point of three ends of other end connection
The A poles of stream a reference source U9.
3. the guard method of the overvoltage crowbar of the Switching Power Supply that output voltage according to claim 2 can be adjusted,
It is characterized in that：When output voltage is adjusted, only adjustment adjustable resistance R1001, output voltage required electricity is adjusted to
Pressure value, crosses pressure point simultaneously in adjustment；
Design calculation process is as follows：
K pole tension (the units of three end adjustable shunt reference source U8：V)：
If simultaneously R1004 is R1003：
If simultaneously R19 is R18：
Output voltage is (unit：V)：
The over-voltage protection point of output voltage is (unit：V)：
During above-mentioned design is calculated, it is 2.5V directly to take three end adjustable shunt reference voltages；
When resistance R16, R18, R19, R1005, R1003, R1004, R1006, R1007, R1008 and R1002 are definite value, change
During the resistance of R1001, output voltage and output voltage over-voltage protection point also can change into change with R1001, reach output
Voltage is adjustable, and output voltage over-voltage protection point is adjustable therewith；
Wherein R16=18Kohm, R18=NC, R19=4.6Kohm, R1005=22Kohm, R1003=4.7Kohm, R1004=
NC, R1006=4.7Kohm, R1007=4.7Kohm, R1008=4.7Kohm, R1002=4.7Kohm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410018881.XA CN103715660B (en) | 2014-01-16 | 2014-01-16 | Overvoltage protection circuit and method for switching power supply with output voltages adjustable |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410018881.XA CN103715660B (en) | 2014-01-16 | 2014-01-16 | Overvoltage protection circuit and method for switching power supply with output voltages adjustable |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103715660A CN103715660A (en) | 2014-04-09 |
| CN103715660B true CN103715660B (en) | 2017-05-03 |
Family
ID=50408398
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410018881.XA Expired - Fee Related CN103715660B (en) | 2014-01-16 | 2014-01-16 | Overvoltage protection circuit and method for switching power supply with output voltages adjustable |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103715660B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104300779B (en) * | 2014-10-21 | 2017-07-21 | 陕西华经微电子股份有限公司 | Output voltage meets the DC/DC converters of y=kx+b relations with regulation voltage |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0151856B1 (en) * | 1984-01-19 | 1990-09-05 | Sharp Kabushiki Kaisha | Power on-off control circuit |
| CN1808835A (en) * | 2006-01-26 | 2006-07-26 | 李文光 | Lithium ion emergency vehicle startup power supply |
| CN201171186Y (en) * | 2008-03-12 | 2008-12-24 | 陈恩临 | Switch power supply type electric screwdriver power supply |
| CN102820645A (en) * | 2012-06-08 | 2012-12-12 | 深圳市共进电子股份有限公司 | High-precision overvoltage protection circuit and switch power circuit with multiplexed output |
-
2014
- 2014-01-16 CN CN201410018881.XA patent/CN103715660B/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0151856B1 (en) * | 1984-01-19 | 1990-09-05 | Sharp Kabushiki Kaisha | Power on-off control circuit |
| CN1808835A (en) * | 2006-01-26 | 2006-07-26 | 李文光 | Lithium ion emergency vehicle startup power supply |
| CN201171186Y (en) * | 2008-03-12 | 2008-12-24 | 陈恩临 | Switch power supply type electric screwdriver power supply |
| CN102820645A (en) * | 2012-06-08 | 2012-12-12 | 深圳市共进电子股份有限公司 | High-precision overvoltage protection circuit and switch power circuit with multiplexed output |
Also Published As
| Publication number | Publication date |
|---|---|
| CN103715660A (en) | 2014-04-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US20150171754A1 (en) | Primary side current regulation on llc converters for led driving | |
| CN105226916A (en) | The current sample method of isolated power converters and sampling apparatus | |
| WO2016049988A1 (en) | Smart matching step-down circuit and travel-use power conversion device | |
| CN103199714B (en) | Power source device of electrophoresis system | |
| CN103715660B (en) | Overvoltage protection circuit and method for switching power supply with output voltages adjustable | |
| CN203896204U (en) | Direct-current voltage-stabilizing power supply having over-current adjusting and output stabilizing functions | |
| CN203788173U (en) | Simple and high-efficiency DC voltage-stabilizing power supply used for laboratory | |
| CN105990819A (en) | DC voltage detection and protection circuit of low-voltage frequency converter | |
| CN204013208U (en) | A high integration active power factor correcting module unit | |
| CN206585802U (en) | Low-voltage dimming power source | |
| CN208797831U (en) | Resist the power circuit and its electric energy meter of strong magnetic disturbance | |
| CN106793346A (en) | Low-voltage dimming power source | |
| CN206490599U (en) | A kind of printer power supply adapter switching power circuit | |
| CN106707148A (en) | Switch characteristic tester | |
| CN201898443U (en) | Alternating-current/direct-current power supply | |
| CN206628979U (en) | A kind of vehicle-mounted DC/DC power conversion units of high power | |
| CN204669214U (en) | A kind of novel LLC current foldback circuit | |
| CN104049559A (en) | Load control circuit and device | |
| CN209105035U (en) | DC-DC step-down isolation circuit | |
| CN208924116U (en) | A kind of low voltage output circuit and photovoltaic module grade product | |
| CN204103799U (en) | A kind of power circuit of gas ionization pipe | |
| CN103391016B (en) | MOSFET synchronous rectification circuit directly connected in parallel with output capacitor and synchronous rectification method | |
| CN208623949U (en) | A kind of LED light source of the double light sources of twin voltage | |
| CN207200283U (en) | A kind of distribution network voltage based on low pressure trend string reinforcing method falls compensation circuit | |
| CN207518485U (en) | A kind of power supply power cell and power supply |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20170503 |