CN105720551A - Output overcurrent protection circuit of power supply - Google Patents
Output overcurrent protection circuit of power supply Download PDFInfo
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- CN105720551A CN105720551A CN201610259528.XA CN201610259528A CN105720551A CN 105720551 A CN105720551 A CN 105720551A CN 201610259528 A CN201610259528 A CN 201610259528A CN 105720551 A CN105720551 A CN 105720551A
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- resistance
- diode
- audion
- power supply
- output
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/08—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current
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Abstract
The invention discloses an output overcurrent protection circuit of a power supply. The output overcurrent protection circuit comprises a resistor R1, a diode D1, a capacitor C1, a triode Q1 and a diode D2, wherein a negative electrode of the diode D1 is connected with a power supply VCC, a resistor R2, an emitter of the triode Q1, a capacitor c2, an emitter of the triode Q2, a capacitor C3 and an emitter of the triode Q3 respectively, a positive electrode of the diode D1 is connected to the ground capacitor C1 and the resistor R1 separately, the other end of the resistor R1 is connected with the other end of the resistor R2 and a base of the triode Q1 separately, and a collector of the triode Q1 is connected with the other end of the capacitor C2, a base of the triode Q2 and the resistor R5 separately. When the circuit encounters an overcurrent situation, overcurrent protection of a system is triggered, and the output is further sharply reduced or cut off; and different from the traditional scheme, the system output can be in a cut-off state all the time after protection, no output voltage is generated by the system even a short-circuit component is removed, and the output is generated only when the system is powered on again (restarted) after powered off.
Description
Technical field
The present invention relates to a kind of current foldback circuit, the specifically protection circuit of a kind of power supply output overcurrent.
Background technology
It is known that power supply plays in electronic product does indispensable effect, the effect of power supply is exactly by the common current of input, through voltage stabilizing, filtering, transformation, then pure, stable, continuous print electric current flows to other hardware and uses.If it is the brain of human body that CPU is compared to, then power supply is the same with regard to anthropoid heart, per second the beating of heart per minute, supports blood to other organs.If brain is good again, it does not have healthy heart, then human body is also unsound.
But, the pathogenic bacteria of human peripheral is too many, if human body does not have immunity and the resistance of self, will be invaded by extraneous pathogenic bacteria equally, affect the health of human body.In like manner; if the protection system that power supply neither one is good; so, when powering load, due to abnormal conditions; make the voltage that power supply exports; time electric current raises, will having a strong impact on the service behaviour of external device (load), the sound that such as loudspeaker are released can be abnormal ear-piercing; graphic interface flickers etc., even serious words can burn out load.
Therefore, the output of power supply is accomplished by a good protection system.Traditional overcurrent protection the method is, when output short-circuit causes loop current to increase rapidly, output is turned off by Protection control system, but once after abnormal removal, loop normal operation immediately again, export big electric current or big voltage.There is a kind of extreme situation, be when occurring in that short-circuit conditions system output protection, then add again after the very short abnormal removal of time internal short-circuit, such that output cuts in and out in a short period of time, and then damage device (load) below.
Summary of the invention
It is an object of the invention to provide the protection circuit of a kind of power supply output overcurrent, with the problem solving to propose in above-mentioned background technology.
For achieving the above object, the present invention provides following technical scheme:
A kind of protection circuit of power supply output overcurrent, including resistance R1, diode D1, electric capacity C1, audion Q1 and diode D2, described diode D1 negative pole connects power supply VCC respectively, resistance R2, audion Q1 emitter stage, electric capacity C2, audion Q2 emitter stage, electric capacity C3 and audion Q3 emitter stage, diode D1 positive pole connects ground capacity C1 and resistance R1 respectively, the resistance R1 other end connects the resistance R2 other end and audion Q1 base stage respectively, audion Q1 colelctor electrode connects the electric capacity C2 other end respectively, audion Q2 base stage and resistance R5, the resistance R5 other end connects earth resistance R6 respectively, diode D2 positive pole and audion Q3 colelctor electrode, audion Q3 base stage connects earth resistance R3 respectively, the electric capacity C3 other end and audion Q2 colelctor electrode, described diode D2 negative pole connects resistance R4 respectively, diode D3 negative pole and output end vo, the resistance R4 other end connects diode D3 positive pole ground connection.
As the present invention further scheme: described power supply VCC voltage is 12V.
Compared with prior art; the invention has the beneficial effects as follows: the present invention was after stream occurred in circuit; the overcurrent protection of triggering system; and then output strongly reduced or turns off output; with traditional scheme the difference is that; after protection, system output will be constantly in off state, even if removing short-circuit component, system there will not be output voltage.Unless powered on after whole system power down, (restarting) just has output again.
Accompanying drawing explanation
Fig. 1 is the circuit diagram of the protection circuit of power supply output overcurrent.
Detailed description of the invention
Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is clearly and completely described, it is clear that described embodiment is only a part of embodiment of the present invention, rather than whole embodiments.Based on the embodiment in the present invention, the every other embodiment that those of ordinary skill in the art obtain under not making creative work premise, broadly fall into the scope of protection of the invention.
Refer to Fig. 1, in the embodiment of the present invention, a kind of protection circuit of power supply output overcurrent, including resistance R1, diode D1, electric capacity C1, audion Q1 and diode D2, described diode D1 negative pole connects power supply VCC respectively, resistance R2, audion Q1 emitter stage, electric capacity C2, audion Q2 emitter stage, electric capacity C3 and audion Q3 emitter stage, diode D1 positive pole connects ground capacity C1 and resistance R1 respectively, the resistance R1 other end connects the resistance R2 other end and audion Q1 base stage respectively, audion Q1 colelctor electrode connects the electric capacity C2 other end respectively, audion Q2 base stage and resistance R5, the resistance R5 other end connects earth resistance R6 respectively, diode D2 positive pole and audion Q3 colelctor electrode, audion Q3 base stage connects earth resistance R3 respectively, the electric capacity C3 other end and audion Q2 colelctor electrode, described diode D2 negative pole connects resistance R4 respectively, diode D3 negative pole and output end vo, the resistance R4 other end connects diode D3 positive pole ground connection；Described power supply VCC voltage is 12V.
The operation principle of the present invention is: refer to Fig. 1, and in normal circuit operation situation of the present invention, Q1 and Q2 is closed mode, and Q3 base stage is low level, and Q3 turns on, and VCC exports load through Q3, D2；When, after load short circuits, the base stage of Q2 is pulled down to low level state through R4, R5, and then makes Q2 turn on, the base stage of the C of Q2 extremely high level and Q3 is high, it is suppressed that the conducting of Q3, turns off output, even if removing the load of short circuit, Q2 still turns on, and makes to be output as 0.
It is obvious to a person skilled in the art that the invention is not restricted to the details of above-mentioned one exemplary embodiment, and when without departing substantially from the spirit of the present invention or basic feature, it is possible to realize the present invention in other specific forms.Therefore, no matter from which point, embodiment all should be regarded as exemplary, and be nonrestrictive, the scope of the invention rather than described above limits, it is intended that all changes in the implication of the equivalency dropping on claim and scope included in the present invention.Any accompanying drawing labelling in claim should be considered as the claim that restriction is involved.
In addition, it is to be understood that, although this specification is been described by according to embodiment, but not each embodiment only comprises an independent technical scheme, this narrating mode of description is only for clarity sake, description should be made as a whole by those skilled in the art, and the technical scheme in each embodiment through appropriately combined, can also form other embodiments that it will be appreciated by those skilled in the art that.
Claims (2)
1. the protection circuit of a power supply output overcurrent, including resistance R1, diode D1, electric capacity C1, audion Q1 and diode D2, it is characterized in that, described diode D1 negative pole connects power supply VCC respectively, resistance R2, audion Q1 emitter stage, electric capacity C2, audion Q2 emitter stage, electric capacity C3 and audion Q3 emitter stage, diode D1 positive pole connects ground capacity C1 and resistance R1 respectively, the resistance R1 other end connects the resistance R2 other end and audion Q1 base stage respectively, audion Q1 colelctor electrode connects the electric capacity C2 other end respectively, audion Q2 base stage and resistance R5, the resistance R5 other end connects earth resistance R6 respectively, diode D2 positive pole and audion Q3 colelctor electrode, audion Q3 base stage connects earth resistance R3 respectively, the electric capacity C3 other end and audion Q2 colelctor electrode, described diode D2 negative pole connects resistance R4 respectively, diode D3 negative pole and output end vo, the resistance R4 other end connects diode D3 positive pole ground connection.
2. the protection circuit of power supply output overcurrent according to claim 1, it is characterised in that described power supply VCC voltage is 12V.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610259528.XA CN105720551A (en) | 2016-04-25 | 2016-04-25 | Output overcurrent protection circuit of power supply |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610259528.XA CN105720551A (en) | 2016-04-25 | 2016-04-25 | Output overcurrent protection circuit of power supply |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN105720551A true CN105720551A (en) | 2016-06-29 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610259528.XA Pending CN105720551A (en) | 2016-04-25 | 2016-04-25 | Output overcurrent protection circuit of power supply |
Country Status (1)
| Country | Link |
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| CN (1) | CN105720551A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107069650A (en) * | 2016-11-07 | 2017-08-18 | 天津津航计算技术研究所 | A kind of amperometric sensor current foldback circuit |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6404608B1 (en) * | 1990-10-12 | 2002-06-11 | Tyco Electronics Uk Ltd. | Overcurrent protection device |
| CN101582580A (en) * | 2009-06-09 | 2009-11-18 | 广州金升阳科技有限公司 | Input/output over-voltage protection circuit |
| CN202712818U (en) * | 2012-07-11 | 2013-01-30 | 深圳市高标电子科技有限公司 | Hall sensor short-circuit protection circuit, motor controller and electric car |
| CN203056540U (en) * | 2013-01-28 | 2013-07-10 | 苏州市泛友实业有限公司 | Auxiliary output protective circuit for Set Top Box circuit board |
-
2016
- 2016-04-25 CN CN201610259528.XA patent/CN105720551A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6404608B1 (en) * | 1990-10-12 | 2002-06-11 | Tyco Electronics Uk Ltd. | Overcurrent protection device |
| CN101582580A (en) * | 2009-06-09 | 2009-11-18 | 广州金升阳科技有限公司 | Input/output over-voltage protection circuit |
| CN202712818U (en) * | 2012-07-11 | 2013-01-30 | 深圳市高标电子科技有限公司 | Hall sensor short-circuit protection circuit, motor controller and electric car |
| CN203056540U (en) * | 2013-01-28 | 2013-07-10 | 苏州市泛友实业有限公司 | Auxiliary output protective circuit for Set Top Box circuit board |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107069650A (en) * | 2016-11-07 | 2017-08-18 | 天津津航计算技术研究所 | A kind of amperometric sensor current foldback circuit |
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Application publication date: 20160629 |
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| RJ01 | Rejection of invention patent application after publication |