CN112467967A - Overvoltage protection structure of switching power supply - Google Patents
Overvoltage protection structure of switching power supply Download PDFInfo
- Publication number
- CN112467967A CN112467967A CN202011322180.7A CN202011322180A CN112467967A CN 112467967 A CN112467967 A CN 112467967A CN 202011322180 A CN202011322180 A CN 202011322180A CN 112467967 A CN112467967 A CN 112467967A
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- Prior art keywords
- resistor
- overvoltage protection
- power supply
- circuit
- switching power
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- 238000001514 detection method Methods 0.000 claims abstract description 12
- 238000004804 winding Methods 0.000 claims abstract description 10
- 238000010521 absorption reaction Methods 0.000 claims abstract description 6
- 238000009499 grossing Methods 0.000 claims abstract description 6
- 239000003990 capacitor Substances 0.000 claims description 12
- 230000003287 optical effect Effects 0.000 claims description 6
- 230000001960 triggered effect Effects 0.000 abstract description 4
- 230000009471 action Effects 0.000 abstract description 3
- 230000010355 oscillation Effects 0.000 abstract description 3
- 230000006872 improvement Effects 0.000 abstract description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000004075 alteration Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
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Classifications
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/32—Means for protecting converters other than automatic disconnection
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
- H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
- H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
- H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
- H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/33569—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements
- H02M3/33576—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements having at least one active switching element at the secondary side of an isolation transformer
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Dc-Dc Converters (AREA)
Abstract
The invention relates to a design improvement of a switching power supply, in particular to an overvoltage protection structure of the switching power supply, which comprises an input filter circuit, an input rectification smoothing circuit, a DCR absorption circuit, an output rectification circuit, an output filter circuit and an output control part, and also comprises an overvoltage protection circuit I and an overvoltage protection circuit II; the output voltage signal can be detected by a detection part of the first overvoltage protection circuit, the high and low potentials of the (OVP/ZCD) No. 1 pin of the IC201 are changed by a control part, and the IC201 is internally triggered to stop the oscillation of the switching power supply so as to realize the overvoltage protection action of the switching power supply; furthermore, by using the turn ratio of the output end winding of the transformer T201 and the winding of the IC power supply end through the second overvoltage protection circuit, when the output voltage is abnormally increased, the winding voltage of the IC power supply portion is also increased, and when the No. 1 pin of the IC201 detects an abnormally high voltage, the IC201 is internally triggered.
Description
Technical Field
The invention relates to design improvement of a switching power supply, in particular to an overvoltage protection structure of the switching power supply.
Background
A switching power supply, which is a high-frequency power conversion device and a power supply. The function is to convert a level voltage into a voltage or current required by the user terminal through different types of architectures. The input of the switching power supply is mostly an ac power supply (e.g., commercial power) or a dc power supply, and the output is mostly equipment requiring a dc power supply, such as a personal computer, and the switching power supply performs voltage and current conversion between the two.
One of the factors for evaluating the quality of the switching power supply is the overvoltage protection function of the switching power supply, and once the output voltage of the switching power supply suddenly rises, the external load is easily damaged, so how to realize the effective overvoltage protection of the switching power supply is a technical problem to be solved.
Disclosure of Invention
In view of the problems mentioned in the background art, it is an object of the present invention to provide an overvoltage protection structure of a switching power supply, which can stably provide an overvoltage protection function according to the needs of the switching power supply.
The technical purpose of the invention is realized by the following technical scheme: an overvoltage protection structure of a switching power supply is characterized in that: the input filter circuit passes through the input rectification smoothing circuit and then respectively passes through the DCR absorption circuit, the transformer, the output rectification circuit and then the output filter circuit, and is connected with the output control part;
the overvoltage protection circuit comprises a detection part and a control part;
the detection part comprises a voltage-regulator tube ZD521, a resistor R522 and an input part of an optical coupler PC202, the voltage-regulator tube ZD521 and the resistor R522 are connected in series and then are connected in parallel with an output part of the switching power supply, and the input part of the optical coupler PC202 is connected in parallel with the resistor R522;
the control part comprises an output part of an optocoupler PC202, a capacitor C211 and a triode TR202, the output part of the optocoupler PC202 is connected with the capacitor C211 in parallel, the output part of the optocoupler PC202 is also connected with the base electrode of the triode TR202 through a resistor R233, the emitter electrode of the triode TR202 is connected with the No. 6 pin of the IC201 chip, and the collector electrode of the triode TR202 is connected with the No. 1 pin of the IC201 chip through a resistor R234;
the overvoltage protection circuit comprises a transformer T201, a resistor R202 and a resistor R203, wherein the resistor R201, the resistor R202 and the resistor R203 are sequentially connected in series and then connected in parallel with a winding of an IC power supply part of the transformer T201, and an IC201 chip is connected in parallel with the resistor R201 and the resistor R202 through a No. 6 pin and a No. 1 pin and R205 through D201 and R202.
Preferably, the overvoltage protection circuit detection unit further includes a diode ZD522 and a resistor R521, and the diode ZD522 and the resistor R521 are further connected in series with the resistor R522 in this order.
Preferably, the emitter of the transistor TR202 and the base of the transistor TR202 are connected in series with a capacitor C210.
Preferably, the emitter of the transistor TR202 and the base of the transistor TR202 are further connected in series with a resistor R232.
Preferably, the capacitor C210 is connected in parallel with the resistor R232.
In summary, the invention mainly has the following beneficial effects: the overvoltage protection structure of the switching power supply can detect an output voltage signal through the detection part of the first overvoltage protection circuit, change the high and low potential of the No. 1 pin (OVP/ZCD) of the IC201 through the control part, trigger the IC201 internally, stop the oscillation of the switching power supply, and realize the overvoltage protection action of the switching power supply; in addition, through the second overvoltage protection circuit, by utilizing the turn ratio of the output end winding of the transformer T201 and the winding of the IC power supply end, when the output voltage is abnormally increased, the winding voltage of the IC power supply part is also increased, and when the (OVP/ZCD) No. 1 pin of the IC201 detects abnormally high voltage, the IC201 is internally triggered to stop the oscillation of the switching power supply, so that the overvoltage protection action of the switching power supply is realized. Therefore, the two detection circuits perform overvoltage detection and overvoltage protection functions on the switching power supply.
Drawings
Fig. 1 is a circuit schematic diagram of an overvoltage protection arrangement of a switching power supply of the present invention;
FIG. 2 is a circuit schematic of a first overvoltage protection circuit of the present invention;
fig. 3 is a circuit diagram of a second overvoltage protection circuit of the invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
An overvoltage protection structure of a switching power supply comprises an input filter circuit, an input rectifying and smoothing circuit, a DCR absorption circuit, an output rectifying circuit, an output filter circuit and an output control part, wherein the input filter circuit passes through the input rectifying and smoothing circuit and then respectively passes through the DCR absorption circuit, the transformer transforms voltage, the output rectifying circuit and the output filter circuit and then is connected with the output control part, and the overvoltage protection structure further comprises an overvoltage protection circuit I and an overvoltage protection circuit II;
the overvoltage protection circuit comprises a detection part and a control part;
the detection part comprises a voltage-regulator tube ZD521, a resistor R522 and an input part of an optical coupler PC202, the voltage-regulator tube ZD521 and the resistor R522 are connected in series and then are connected in parallel with an output part of the switching power supply, and the input part of the optical coupler PC202 is connected in parallel with the resistor R522;
the control part comprises an output part of an optocoupler PC202, a capacitor C211 and a triode TR202, the output part of the optocoupler PC202 is connected with the capacitor C211 in parallel, the output part of the optocoupler PC202 is also connected with the base electrode of the triode TR202 through a resistor R233, the emitter electrode of the triode TR202 is connected with the No. 6 pin of the IC201 chip, and the collector electrode of the triode TR202 is connected with the No. 1 pin of the IC201 chip through a resistor R234;
the overvoltage protection circuit comprises a transformer T201, a resistor R202 and a resistor R203, wherein the resistor R201, the resistor R202 and the resistor R203 are sequentially connected in series and then connected in parallel with a winding of an IC power supply part of the transformer T201, and an IC201 chip is connected in parallel with the resistor R201 and the resistor R202 through a No. 6 pin and a No. 1 pin and R205 through D201 and R202.
The emitter of the transistor TR202 and the base of the transistor TR202 are connected in series with a capacitor C210.
The capacitor C210 is connected in parallel with the resistor R232.
In specific implementation, the voltage obtained by the T201 winding wire is divided by the resistors R201, R202 and R203 and then is respectively connected with the No. 1 pin and the No. 6 pin of the IC201 chip, so that the overvoltage protection function of the overvoltage protection circuit II is realized; and moreover, the on and off functions are realized through the cooperation of the optocoupler PC202 and the triode TR202, so that the high and low potentials of the No. 1 pin of the IC201 chip are changed, the IC201 is triggered internally, and the overvoltage protection is realized.
Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
Claims (5)
1. An overvoltage protection structure of a switching power supply is characterized in that: including input filter circuit, input rectification smoothing circuit, DCR absorption circuit, output rectifier circuit, output filter circuit and output control portion, input filter circuit passes through input rectification smoothing circuit after the rethread and passes through DCR absorption circuit respectively, through the transformer vary voltage after, through output rectifier circuit, rethread output filter circuit back connection output control portion, its characterized in that: the overvoltage protection circuit comprises a first overvoltage protection circuit and a second overvoltage protection circuit;
the overvoltage protection circuit comprises a detection part and a control part;
the detection part comprises a voltage-regulator tube ZD521, a resistor R522 and an input part of an optical coupler PC202, the voltage-regulator tube ZD521 and the resistor R522 are connected in series and then are connected in parallel with an output part of the switching power supply, and the input part of the optical coupler PC202 is connected in parallel with the resistor R522;
the control part comprises an output part of an optocoupler PC202, a capacitor C211 and a triode TR202, the output part of the optocoupler PC202 is connected with the capacitor C211 in parallel, the output part of the optocoupler PC202 is also connected with the base electrode of the triode TR202 through a resistor R233, the emitter electrode of the triode TR202 is connected with the No. 6 pin of the IC201 chip, and the collector electrode of the triode TR202 is connected with the No. 1 pin of the IC201 chip through a resistor R234;
the overvoltage protection circuit comprises a transformer T201, a resistor R202 and a resistor R203, wherein the resistor R201, the resistor R202 and the resistor R203 are sequentially connected in series and then connected in parallel with a winding of an IC power supply part of the transformer T201, and an IC201 chip is connected in parallel with the resistor R201 and the resistor R202 through a No. 6 pin and a No. 1 pin and R205 through D201 and R202.
2. The overvoltage protection structure of a switching power supply according to claim 1, wherein: the overvoltage protection circuit detection part further comprises a diode ZD522 and a resistor R521, and the diode ZD522 and the resistor R521 are further sequentially connected with the resistor R522 in series.
3. The overvoltage protection structure of a switching power supply according to claim 1, wherein: the emitter of the transistor TR202 and the base of the transistor TR202 are connected in series with a capacitor C210.
4. The overvoltage protection structure of a switching power supply according to claim 1, wherein: the emitter of the triode TR202 and the base of the triode TR202 are also connected in series with a resistor R232.
5. The overvoltage protection structure of the switching power supply according to claims 3 and 4, wherein: the capacitor C210 is connected in parallel with the resistor R232.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011322180.7A CN112467967A (en) | 2020-11-23 | 2020-11-23 | Overvoltage protection structure of switching power supply |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011322180.7A CN112467967A (en) | 2020-11-23 | 2020-11-23 | Overvoltage protection structure of switching power supply |
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| Publication Number | Publication Date |
|---|---|
| CN112467967A true CN112467967A (en) | 2021-03-09 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011322180.7A Pending CN112467967A (en) | 2020-11-23 | 2020-11-23 | Overvoltage protection structure of switching power supply |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103474965A (en) * | 2013-08-27 | 2013-12-25 | 崧顺电子（深圳）有限公司 | Low-cost alternating-current input overvoltage protection circuit and switching power supply |
| CN203398768U (en) * | 2013-08-27 | 2014-01-15 | 崧顺电子（深圳）有限公司 | Low-cost AC input overvoltage protection circuit and switching power supply |
| CN103580000A (en) * | 2013-10-21 | 2014-02-12 | 矽力杰半导体技术(杭州)有限公司 | Overvoltage protection method and circuit for switching power supply output and switching power supply provided with the circuit |
| CN205544230U (en) * | 2016-03-08 | 2016-08-31 | 广州视源电子科技股份有限公司 | Ring -opening protection circuit and switching power supply circuit |
| CN110364994A (en) * | 2019-08-12 | 2019-10-22 | 无锡博通微电子技术有限公司 | A kind of switching power circuit and method with the protection of accurate electric voltage exception |
-
2020
- 2020-11-23 CN CN202011322180.7A patent/CN112467967A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103474965A (en) * | 2013-08-27 | 2013-12-25 | 崧顺电子（深圳）有限公司 | Low-cost alternating-current input overvoltage protection circuit and switching power supply |
| CN203398768U (en) * | 2013-08-27 | 2014-01-15 | 崧顺电子（深圳）有限公司 | Low-cost AC input overvoltage protection circuit and switching power supply |
| CN103580000A (en) * | 2013-10-21 | 2014-02-12 | 矽力杰半导体技术(杭州)有限公司 | Overvoltage protection method and circuit for switching power supply output and switching power supply provided with the circuit |
| CN205544230U (en) * | 2016-03-08 | 2016-08-31 | 广州视源电子科技股份有限公司 | Ring -opening protection circuit and switching power supply circuit |
| CN110364994A (en) * | 2019-08-12 | 2019-10-22 | 无锡博通微电子技术有限公司 | A kind of switching power circuit and method with the protection of accurate electric voltage exception |
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Application publication date: 20210309 |