CN204190358U - A kind of LED power protective circuit turning off PWM chip and export - Google Patents
A kind of LED power protective circuit turning off PWM chip and export Download PDFInfo
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- CN204190358U CN204190358U CN201420690590.0U CN201420690590U CN204190358U CN 204190358 U CN204190358 U CN 204190358U CN 201420690590 U CN201420690590 U CN 201420690590U CN 204190358 U CN204190358 U CN 204190358U
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- resistance
- stable pressure
- electric capacity
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- accurate source
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Abstract
The utility model discloses a kind of LED power protective circuit turning off PWM chip and export, it is characterized in that: comprise the first resistance, second resistance, 3rd resistance, 4th resistance, 5th resistance, 6th resistance, 7th resistance, 8th resistance, first electric capacity, second electric capacity, first controllable accurate source of stable pressure, second controllable accurate source of stable pressure, photoelectrical coupler, isolated gate FET and DC power supply, first resistance ~ the 5th resistance, first electric capacity, second electric capacity, first controllable accurate source of stable pressure, second controllable accurate source of stable pressure and photoelectrical coupler form optical coupling isolation circuit, 6th resistance ~ the 8th resistance and isolated gate FET form protection switch circuit.The utility model, by PWM chip voltage output end is pulled low to electronegative potential, turns off the output of PWM chip, reaches the object of protection LED power fast, avoids the restriction by PWM chip self feedback loop speed, be beneficial to the reliability improving protective circuit.
Description
Technical field
The utility model relates to a kind of LED power protective circuit turning off PWM chip and export.
Background technology
LED power when output short-circuit or overcurrent, often exist burn out sampling resistor, damage control chip, damage switching tube, power supply has the hiccups and the problem such as short-circuit dissipation is large, need be provided with short-circuit protection circuit.At present; the closed feedback loop of the pwm chip self in general employing LED power is protected LED power, is subject to the restriction of feedback loop speed, if pwm chip does not have overcurrent short-circuit protection function simultaneously; then need otherwise designed protective circuit, strengthen design cost.
Summary of the invention
For above-mentioned the deficiencies in the prior art part, the utility model provides a kind of LED power protective circuit turning off PWM chip and export.
To achieve these goals, the technical solution adopted in the utility model is:
A kind of LED power protective circuit turning off PWM chip and export described in the utility model, is characterized in that: comprise the first resistance, second resistance, 3rd resistance, 4th resistance, 5th resistance, 6th resistance, 7th resistance, 8th resistance, first electric capacity, second electric capacity, first controllable accurate source of stable pressure, second controllable accurate source of stable pressure, photoelectrical coupler, isolated gate FET and DC power supply, the described first end of the first resistance is connected with the cathode output end of LED power, the second end of described first resistance simultaneously with the first end of the second resistance, the reference pole of the first controllable accurate source of stable pressure connects, the negative pole of described DC power supply simultaneously with the anode of the first controllable accurate source of stable pressure, the anode of the second controllable accurate source of stable pressure, the first end of the first electric capacity connects, the second end of described second resistance simultaneously with the first end of the 3rd resistance, second end of the first electric capacity, the negative electrode of the second controllable accurate source of stable pressure, the reference pole of the second controllable accurate source of stable pressure connects, the positive pole of described DC power supply simultaneously with the second end of the 3rd resistance, the first end of the 4th resistance, the first end of the 5th resistance connects, and the second end of described 4th resistance is connected with the first end of the second electric capacity, with the second end of the second electric capacity while of the second end of described 5th resistance, the positive pole of photoelectrical coupler connects, and the negative electrode of described first controllable accurate source of stable pressure is connected with the negative pole of photoelectrical coupler, with the first end of the 6th resistance while of the emitter of described photoelectrical coupler, the first end of the 7th resistance connects, the collector electrode of described photoelectrical coupler is as boost voltage input, second end of described 6th resistance is connected with the grid of isolated gate FET, the drain electrode of described isolated gate FET is connected with the first end of the 8th resistance, receive the cathode output end of PWM chip after second end of described 7th resistance is connected with the source electrode of isolated gate FET, the second end of described 8th resistance receives the cathode output end of PWM chip.
Compared with prior art, the beneficial effects of the utility model:
A kind of LED power protective circuit turning off PWM chip and export described in the utility model; by PWM chip voltage output end is pulled low to electronegative potential; turn off the output of PWM chip; reach the object of protection LED power fast; avoid the restriction by PWM chip self feedback loop speed, be beneficial to the reliability improving protective circuit.
Accompanying drawing explanation
Fig. 1 is a kind of circuit diagram turning off the LED power protective circuit that PWM chip exports described in the utility model.
Embodiment
Below in conjunction with drawings and the specific embodiments, the utility model is described in further detail.
As shown in Figure 1, a kind of LED power protective circuit turning off PWM chip and export described in the utility model, is characterized in that: comprise the first resistance R1, second resistance R2, 3rd resistance R3, 4th resistance R4, 5th resistance R5, 6th resistance R6, 7th resistance R7, 8th resistance R8, first electric capacity C1, second electric capacity C2, first controllable accurate source of stable pressure UB1, second controllable accurate source of stable pressure UB2, photoelectrical coupler U, isolated gate FET M and DC power supply VCC, the first end of described first resistance R1 is connected with the cathode output end (Vl-) of LED power, second end of described first resistance R1 simultaneously with the first end of the second resistance R2, the reference pole of the first controllable accurate source of stable pressure UB1 connects, the negative pole of described DC power supply VCC simultaneously with the anode of the first controllable accurate source of stable pressure UB1, the anode of the second controllable accurate source of stable pressure UB2, the first end of the first electric capacity C1 connects, second end of described second resistance R2 simultaneously with the first end of the 3rd resistance R3, second end of the first electric capacity C1, the negative electrode of the second controllable accurate source of stable pressure UB2, the reference pole of the second controllable accurate source of stable pressure UB2 connects, the positive pole of described DC power supply VCC simultaneously with second end of the 3rd resistance R3, the first end of the 4th resistance R4, the first end of the 5th resistance R5 connects, and second end of described 4th resistance R4 is connected with the first end of the second electric capacity C2, with second end of the second electric capacity C2 while of second end of described 5th resistance R5, the positive pole of photoelectrical coupler U connects, and the negative electrode of described first controllable accurate source of stable pressure UB1 is connected with the negative pole of photoelectrical coupler U, with the first end of the 6th resistance R6 while of the emitter of described photoelectrical coupler U, the first end of the 7th resistance R7 connects, the collector electrode of described photoelectrical coupler U is as boost voltage input Vr, second end of described 6th resistance R6 is connected with the grid of isolated gate FET M, the drain electrode of described isolated gate FET M is connected with the first end of the 8th resistance R8, receive the cathode output end of PWM chip after second end of described 7th resistance R7 is connected with the source electrode of isolated gate FET M, second end of described 8th resistance R8 receives the cathode output end of PWM chip.
A kind of LED power protective circuit turning off PWM chip and export described in the utility model; first resistance R1, the second resistance R2, the 3rd resistance R3, the 4th resistance R4, the 5th resistance R5, the first electric capacity C1, the second electric capacity C2, the first controllable accurate source of stable pressure UB1, the second controllable accurate source of stable pressure UB2 and photoelectrical coupler U form optical coupling isolation circuit, and the 6th resistance R6, the 7th resistance R7, the 8th resistance R8 and isolated gate FET M form protection switch circuit.When the short circuit of LED output or overcurrent; cathode output end (Vl-) voltage of LED power raises; make the first controllable accurate source of stable pressure UB1 conducting; photoelectrical coupler U conducting; under boost voltage Vr effect, isolated gate FET M conducting, is pulled to electronegative potential by the voltage output end of PWM chip; turn off the output of PWM chip, reach the object protecting LED power fast.This protective circuit, by PWM chip voltage output end is pulled low to electronegative potential, turns off the output of PWM chip, reaches the object of protection LED power fast, avoids the restriction by PWM chip self feedback loop speed, be beneficial to the reliability improving protective circuit.
Claims (1)
1. turn off the LED power protective circuit that PWM chip exports, it is characterized in that: comprise the first resistance, second resistance, 3rd resistance, 4th resistance, 5th resistance, 6th resistance, 7th resistance, 8th resistance, first electric capacity, second electric capacity, first controllable accurate source of stable pressure, second controllable accurate source of stable pressure, photoelectrical coupler, isolated gate FET and DC power supply, the described first end of the first resistance is connected with the cathode output end of LED power, the second end of described first resistance simultaneously with the first end of the second resistance, the reference pole of the first controllable accurate source of stable pressure connects, the negative pole of described DC power supply simultaneously with the anode of the first controllable accurate source of stable pressure, the anode of the second controllable accurate source of stable pressure, the first end of the first electric capacity connects, the second end of described second resistance simultaneously with the first end of the 3rd resistance, second end of the first electric capacity, the negative electrode of the second controllable accurate source of stable pressure, the reference pole of the second controllable accurate source of stable pressure connects, the positive pole of described DC power supply simultaneously with the second end of the 3rd resistance, the first end of the 4th resistance, the first end of the 5th resistance connects, and the second end of described 4th resistance is connected with the first end of the second electric capacity, with the second end of the second electric capacity while of the second end of described 5th resistance, the positive pole of photoelectrical coupler connects, and the negative electrode of described first controllable accurate source of stable pressure is connected with the negative pole of photoelectrical coupler, with the first end of the 6th resistance while of the emitter of described photoelectrical coupler, the first end of the 7th resistance connects, the collector electrode of described photoelectrical coupler is as boost voltage input, second end of described 6th resistance is connected with the grid of isolated gate FET, the drain electrode of described isolated gate FET is connected with the first end of the 8th resistance, receive the cathode output end of PWM chip after second end of described 7th resistance is connected with the source electrode of isolated gate FET, the second end of described 8th resistance receives the cathode output end of PWM chip.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420690590.0U CN204190358U (en) | 2014-11-18 | 2014-11-18 | A kind of LED power protective circuit turning off PWM chip and export |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420690590.0U CN204190358U (en) | 2014-11-18 | 2014-11-18 | A kind of LED power protective circuit turning off PWM chip and export |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN204190358U true CN204190358U (en) | 2015-03-04 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201420690590.0U Expired - Fee Related CN204190358U (en) | 2014-11-18 | 2014-11-18 | A kind of LED power protective circuit turning off PWM chip and export |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN204190358U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108565823A (en) * | 2018-02-07 | 2018-09-21 | 北京航天发射技术研究所 | A kind of low cost isolated form high voltage bus over under-voltage protection circuit |
| CN113009229A (en) * | 2021-03-16 | 2021-06-22 | 东风汽车集团股份有限公司 | Detection circuit and detection method for automobile insulation resistance value |
-
2014
- 2014-11-18 CN CN201420690590.0U patent/CN204190358U/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108565823A (en) * | 2018-02-07 | 2018-09-21 | 北京航天发射技术研究所 | A kind of low cost isolated form high voltage bus over under-voltage protection circuit |
| CN108565823B (en) * | 2018-02-07 | 2020-03-03 | 北京航天发射技术研究所 | Low-cost isolated high-voltage bus overvoltage and undervoltage protection circuit |
| CN113009229A (en) * | 2021-03-16 | 2021-06-22 | 东风汽车集团股份有限公司 | Detection circuit and detection method for automobile insulation resistance value |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20150304 Termination date: 20151118 |
|
| EXPY | Termination of patent right or utility model |