CN105071339A - Over-current protection circuit - Google Patents
Over-current protection circuit Download PDFInfo
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- CN105071339A CN105071339A CN201510432770.8A CN201510432770A CN105071339A CN 105071339 A CN105071339 A CN 105071339A CN 201510432770 A CN201510432770 A CN 201510432770A CN 105071339 A CN105071339 A CN 105071339A
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- field effect
- effect transistor
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Abstract
The invention relates to a circuit, and specifically relates to an over-current protection circuit. The over-current protection circuit comprises an oscillator, field effect transistors and triodes. A power supply pin of the oscillator is connected with a power supply. A source electrode of the field effect transistor Q1 and a source electrode of the field effect transistor Q4 are connected and are together connected with a feedback resistor R10, and the resistor R10 is simultaneously grounded. An input pin +IN of the oscillator is connected with the resistor R10 through a diode D1 and is simultaneously connected with a PWN pin of the oscillator through a diode D2. A cathode of the diode D1 is connected with a pin +IN1. A cathode of the diode Ds is connected with the pin +IN. A REF pin of the oscillator is connected with a voltage dividing resistor R1 and a resistor R2. One end of the resistor R2 is grounded. The common end of the resistor R1 and the resistor R2 is connected with a pin -IN end.
Description
technical field:
The present invention relates to a kind of circuit, be specifically related to a kind of current foldback circuit.
background technology:
The way of output of pulse width modulation, has been used in many consumption kinds very widely, has particularly been applied in portable electronic product.Using battery as in the portable product of energy source, power consumption is one of most important Consideration always, and the advantage that the way of output of pulse-width modulation is maximum is exactly its high power efficiency.In pulse width regulating circuit, the measure of overcurrent protection is not fully up to expectations.
summary of the invention:
The present invention is just to provide current foldback circuit in a kind of pulse width regulating circuit.
Technical scheme provided by the invention is:
Current foldback circuit, include oscillator, field effect transistor and triode, the power pins of oscillator connects power supply, C1 with the C2 pin of oscillator is connected power supply respectively by resistance R4 with resistance R5, E1, E2, GND pin ground connection simultaneously of oscillator, C1 with the C2 pin of oscillator is connected respectively with two-way circuit respectively, the C2 pin of oscillator is connected with the base stage of the grid of field effect transistor Q1 and triode Q6 simultaneously, the C1 pin of oscillator is connected with the base stage of the grid of field effect transistor Q4 and triode Q5 simultaneously, the emitter of triode Q6 is connected with triode Q5 emitter and simultaneously ground connection, the base stage of triode Q6 is connected with triode Q5 base stage and simultaneously ground connection, triode Q5 collector electrode is connected with the grid meeting field effect transistor Q3, the collector electrode of triode Q6 is connected with the grid of field effect transistor Q2, the drain electrode of field effect transistor Q3 exports after being connected with the source electrode of field effect transistor Q4, the drain electrode of field effect transistor Q1 exports after being connected with the grid of field effect transistor Q2, and the drain electrode of field effect transistor Q2 is connected with field effect transistor Q3 drain electrode and is connected power supply simultaneously, the grid of field effect transistor Q2 is connected with the grid of field effect transistor Q3 simultaneously and connects power supply simultaneously, the source electrode of field effect transistor Q1 is connected with the source electrode of field effect transistor Q4 and is connected feedback resistance R10 simultaneously, resistance R10 is ground connection simultaneously, input pin+the IN of described oscillator is connected with resistance R10 by diode D1 and is connected by diode D2 and oscillator PWN pin simultaneously, the negative pole of diode D1 is connected with pin+IN1, the negative pole of diode D2 is connected with pin+IN, the REF pin of oscillator connects divider resistance R1 and resistance R2, resistance R2 one end ground connection, resistance R1 is connected pin-IN and holds with the common port of resistance R2.
Concrete, described oscillator Cr pin is by electric capacity C ground connection, and Rr pin is by resistance R3 ground connection.
Concrete, series resistance R7 and resistance R6 is set between the grid of described field effect transistor Q1 and the base stage of triode Q6.
Concrete, series resistance R14 and resistance R13 is set between the grid of described field effect transistor Q4 and the base stage of triode Q5.
Concrete, the drain electrode of described field effect transistor Q2 connects power supply by resistance R15, and field effect transistor Q3 drain electrode connects power supply by resistance R8.
Structure of the present invention is simple; design concept is ingenious; circuit operates steadily reliably, in circuit running, when the electric current at resistance R10 place increases; the magnitude of voltage of+IN input increases; when the magnitude of voltage of IN input is greater than the reference voltage of-IN end, PWN can control to export and close, and to feed back to+IN by diode D2 thus lock it be high voltage always; circuit is played a protective role, extends the useful life of product.The present invention can be widely used in charger, switch power supply.
Accompanying drawing explanation
Fig. 1 is the structural representation of embodiment.
Embodiment
Be illustrated in figure 1.
Current foldback circuit, include oscillator, field effect transistor and triode, the power pins of oscillator connects power supply, C1 with the C2 pin of oscillator is connected power supply respectively by resistance R4 with resistance R5, E1, E2, GND pin ground connection simultaneously of oscillator, C1 with the C2 pin of oscillator is connected respectively with two-way circuit respectively; The C2 pin of oscillator is connected with the base stage of the grid of field effect transistor Q1 and triode Q6 simultaneously, arranges series resistance R7 and resistance R6 between the grid of described field effect transistor Q1 and the base stage of triode Q6.The C1 pin of oscillator is connected with the base stage of the grid of field effect transistor Q4 and triode Q5 simultaneously, arranges series resistance R14 and resistance R13 between the grid of described field effect transistor Q4 and the base stage of triode Q5.The emitter of triode Q6 is connected with triode Q5 emitter and simultaneously ground connection, the base stage of triode Q6 is connected with triode Q5 base stage and simultaneously ground connection, triode Q5 collector electrode is connected with the grid meeting field effect transistor Q3, the collector electrode of triode Q6 is connected with the grid of field effect transistor Q2, the drain electrode of field effect transistor Q3 exports after being connected with the source electrode of field effect transistor Q4, the drain electrode of field effect transistor Q1 exports after being connected with the grid of field effect transistor Q2, and the drain electrode of field effect transistor Q2 is connected with field effect transistor Q3 drain electrode and is connected power supply simultaneously, the grid of field effect transistor Q2 is connected with the grid of field effect transistor Q3 simultaneously and connects power supply simultaneously.The drain electrode of described field effect transistor Q2 connects power supply by resistance R15, and field effect transistor Q3 drain electrode connects power supply by resistance R8.
The source electrode of field effect transistor Q1 is connected with the source electrode of field effect transistor Q4 and is connected feedback resistance R10 simultaneously, resistance R10 is ground connection simultaneously, input pin+the IN of described oscillator is connected with resistance R10 by diode D1 and is connected by diode D2 and oscillator PWN pin simultaneously, the negative pole of diode D1 is connected with pin+IN1, the negative pole of diode D2 is connected with pin+IN, the REF pin of oscillator connects divider resistance R1 and resistance R2, resistance R2 one end ground connection, resistance R1 is connected pin-IN and holds with the common port of resistance R2.
Described oscillator Cr pin is by electric capacity C ground connection, and Rr pin is by resistance R3 ground connection.
Claims (5)
1. current foldback circuit, include oscillator, field effect transistor and triode, the power pins of oscillator connects power supply, C1 with the C2 pin of oscillator is connected power supply respectively by resistance R4 with resistance R5, E1, E2, GND pin ground connection simultaneously of oscillator, C1 with the C2 pin of oscillator is connected respectively with two-way circuit respectively, the C2 pin of oscillator is connected with the base stage of the grid of field effect transistor Q1 and triode Q6 simultaneously, the C1 pin of oscillator is connected with the base stage of the grid of field effect transistor Q4 and triode Q5 simultaneously, the emitter of triode Q6 is connected with triode Q5 emitter and simultaneously ground connection, the base stage of triode Q6 is connected with triode Q5 base stage and simultaneously ground connection, triode Q5 collector electrode is connected with the grid meeting field effect transistor Q3, the collector electrode of triode Q6 is connected with the grid of field effect transistor Q2, the drain electrode of field effect transistor Q3 exports after being connected with the source electrode of field effect transistor Q4, the drain electrode of field effect transistor Q1 exports after being connected with the grid of field effect transistor Q2, and the drain electrode of field effect transistor Q2 is connected with field effect transistor Q3 drain electrode and is connected power supply simultaneously, the grid of field effect transistor Q2 is connected with the grid of field effect transistor Q3 simultaneously and connects power supply simultaneously, it is characterized in that, the source electrode of field effect transistor Q1 is connected with the source electrode of field effect transistor Q4 and is connected feedback resistance R10 simultaneously, resistance R10 is ground connection simultaneously, input pin+the IN of described oscillator is connected with resistance R10 by diode D1 and is connected by diode D2 and oscillator PWN pin simultaneously, the negative pole of diode D1 is connected with pin+IN1, the negative pole of diode D2 is connected with pin+IN, the REF pin of oscillator connects divider resistance R1 and resistance R2, resistance R2 one end ground connection, resistance R1 is connected pin-IN and holds with the common port of resistance R2.
2. current foldback circuit according to claim 1, is characterized in that, described oscillator Cr pin is by electric capacity C ground connection, and Rr pin is by resistance R3 ground connection.
3. current foldback circuit according to claim 1, is characterized in that, arrange series resistance R7 and resistance R6 between the grid of described field effect transistor Q1 and the base stage of triode Q6.
4. current foldback circuit according to claim 1, is characterized in that, arrange series resistance R14 and resistance R13 between the grid of described field effect transistor Q4 and the base stage of triode Q5.
5. current foldback circuit according to claim 1, is characterized in that, the drain electrode of described field effect transistor Q2 connects power supply by resistance R15, and field effect transistor Q3 drain electrode connects power supply by resistance R8.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510432770.8A CN105071339A (en) | 2015-07-22 | 2015-07-22 | Over-current protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510432770.8A CN105071339A (en) | 2015-07-22 | 2015-07-22 | Over-current protection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN105071339A true CN105071339A (en) | 2015-11-18 |
Family
ID=54500652
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510432770.8A Pending CN105071339A (en) | 2015-07-22 | 2015-07-22 | Over-current protection circuit |
Country Status (1)
| Country | Link |
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| CN (1) | CN105071339A (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11215689A (en) * | 1998-01-28 | 1999-08-06 | Canon Inc | Overcurrent protective device |
| CN101593961A (en) * | 2009-07-07 | 2009-12-02 | 中国科学技术大学 | DC power supply short-circuit protection circuit based on contactless current sample |
| CN202405764U (en) * | 2011-12-27 | 2012-08-29 | 青岛海霸能源集团有限公司 | Over-current protective system for parallel battery packs |
| CN104124948A (en) * | 2014-07-03 | 2014-10-29 | 濮阳市立圆汽车电器有限公司 | Pulse width modulating circuit |
| CN205070388U (en) * | 2015-07-22 | 2016-03-02 | 濮阳市立圆汽车电器有限公司 | Overcurrent protection circuit |
-
2015
- 2015-07-22 CN CN201510432770.8A patent/CN105071339A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11215689A (en) * | 1998-01-28 | 1999-08-06 | Canon Inc | Overcurrent protective device |
| CN101593961A (en) * | 2009-07-07 | 2009-12-02 | 中国科学技术大学 | DC power supply short-circuit protection circuit based on contactless current sample |
| CN202405764U (en) * | 2011-12-27 | 2012-08-29 | 青岛海霸能源集团有限公司 | Over-current protective system for parallel battery packs |
| CN104124948A (en) * | 2014-07-03 | 2014-10-29 | 濮阳市立圆汽车电器有限公司 | Pulse width modulating circuit |
| CN205070388U (en) * | 2015-07-22 | 2016-03-02 | 濮阳市立圆汽车电器有限公司 | Overcurrent protection circuit |
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Application publication date: 20151118 |
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| RJ01 | Rejection of invention patent application after publication |