CN102231511A - LED drive circuit and short-circuit protection circuit thereof - Google Patents
LED drive circuit and short-circuit protection circuit thereof Download PDFInfo
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- CN102231511A CN102231511A CN2011100895408A CN201110089540A CN102231511A CN 102231511 A CN102231511 A CN 102231511A CN 2011100895408 A CN2011100895408 A CN 2011100895408A CN 201110089540 A CN201110089540 A CN 201110089540A CN 102231511 A CN102231511 A CN 102231511A
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Abstract
The invention is applicable to the field of lighting equipment, particularly relates to an LED drive circuit and a short-circuit protection circuit thereof. The short-circuit protection circuit comprises a first switch element, a second switch element, a voltage-dividing resistor R1, a voltage-dividing resistor R2, a voltage-dividing resistor R3, a voltage-dividing resistor R4, a voltage-dividing resistor R5, a voltage-stabilizing diode ZD1 and an inductor C1. In the embodiment of the invention, when an output load is short-circuit, a high electrical level is applied to the control end of the first switch element instantly to switch on the first switch element; and the PWM control end of the direct-current/direct-current constant current unit is earthed via the first switch element to switch off the output of the direct-current/direct-current constant current unit so as to realize the function of protecting load short-circuit.
Description
Technical field
The invention belongs to the lighting apparatus field, relate in particular to a kind of led drive circuit and short-circuit protection circuit thereof.
Background technology
LED is as new type light source, it has energy-saving and environmental protection, characteristics of high efficiency, technology is ripe and be applied to every field, LED is widely used as lighting source, various led drive circuits have also appearred thereupon, led drive circuit generally includes the DC-DC constant current unit that links to each other successively and drives output unit, and DC-DC constant current unit connects DC power supply, drives output unit and connects the LED positive pole.
In the process of work, the load that led drive circuit drives may produce anomaly, such as short circuit phenomenon, if this thing happens, will cause the inner many components and parts in DC-DC constant current unit to damage, severe patient also can cause security incidents such as fire, blast.
Summary of the invention
The object of the present invention is to provide a kind of short-circuit protection circuit of led drive circuit, be intended to solve present led drive circuit and the problem that can be damaged occurring under the situation of load short circuits.
The present invention is achieved in that a kind of short-circuit protection circuit of led drive circuit, connects DC-DC constant current unit and LED negative pole respectively, and described short-circuit protection circuit comprises:
First switch element, second switch element, divider resistance R1, divider resistance R2, divider resistance R3, divider resistance R4, divider resistance R5, voltage stabilizing didoe ZD1 and inductance C1;
The control end of described second switch element connects the power output end of power end and described DC-DC constant current unit by divider resistance R1, the second end ground connection of described second switch element, described divider resistance R2 is connected between the control end and ground of described second switch element, described voltage stabilizing didoe ZD1 is connected between the control end and ground of described second switch element, the first termination LED negative pole of described second switch element, described divider resistance R3 and divider resistance R4 are serially connected between first end and ground of described second switch element, the control termination divider resistance R3 of described first switch element and the public connecting end of divider resistance R4, described inductance C1 is connected between the control end and ground of first switch element, the second end ground connection of described first switch element, first end of described first switch element connect the PWM control end of described DC-DC constant current unit by divider resistance R5.
Another purpose of the present invention is to provide a kind of led drive circuit, comprises DC-DC constant current unit, drives output unit and LED, and described led drive circuit also comprises short-circuit protection circuit, and described short-circuit protection circuit comprises:
First switch element, second switch element, divider resistance R1, divider resistance R2, divider resistance R3, divider resistance R4, divider resistance R5, voltage stabilizing didoe ZD1 and inductance C1;
The control end of described second switch element connects the power output end of power end and described DC-DC constant current unit by divider resistance R1, the second end ground connection of described second switch element, described divider resistance R2 is connected between the control end and ground of described second switch element, described voltage stabilizing didoe ZD1 is connected between the control end and ground of described second switch element, the first termination LED negative pole of described second switch element, described divider resistance R3 and divider resistance R4 are serially connected between first end and ground of described second switch element, the control termination divider resistance R3 of described first switch element and the public connecting end of divider resistance R4, described inductance C1 is connected between the control end and ground of first switch element, the second end ground connection of described first switch element, first end of described first switch element connect the PWM control end of described DC-DC constant current unit by divider resistance R5.
In the present invention; when the output loading short circuit; control end moment of first switch element adds high level; cause the first switch element conducting; the PWM control end of DC-DC constant current unit is by the first switch element ground connection; cause the output of DC-DC constant current unit to be turn-offed, thereby realize the function of load short circuits protection.
Description of drawings
Fig. 1 is the circuit diagram of the led drive circuit that provides of the embodiment of the invention.
Embodiment
In order to make purpose of the present invention, technical scheme and advantage clearer,, the present invention is further elaborated below in conjunction with drawings and Examples.Should be appreciated that specific embodiment described herein only in order to explanation the present invention, and be not used in qualification the present invention.
A kind of short-circuit protection circuit of led drive circuit connects DC-DC constant current unit and LED negative pole respectively, and described short-circuit protection circuit comprises:
First switch element, second switch element, divider resistance R1, divider resistance R2, divider resistance R3, divider resistance R4, divider resistance R5, voltage stabilizing didoe ZD1 and inductance C1;
The control end of described second switch element connects the power output end of power end and described DC-DC constant current unit by divider resistance R1, the second end ground connection of described second switch element, described divider resistance R2 is connected between the control end and ground of described second switch element, described voltage stabilizing didoe ZD1 is connected between the control end and ground of described second switch element, the first termination LED negative pole of described second switch element, described divider resistance R3 and divider resistance R4 are serially connected between first end and ground of described second switch element, the control termination divider resistance R3 of described first switch element and the public connecting end of divider resistance R4, described inductance C1 is connected between the control end and ground of first switch element, the second end ground connection of described first switch element, first end of described first switch element connect the PWM control end of described DC-DC constant current unit by divider resistance R5.
A kind of led drive circuit comprises DC-DC constant current unit, drives output unit and LED, and described led drive circuit also comprises short-circuit protection circuit, and described short-circuit protection circuit comprises:
First switch element, second switch element, divider resistance R1, divider resistance R2, divider resistance R3, divider resistance R4, divider resistance R5, voltage stabilizing didoe ZD1 and inductance C1;
The control end of described second switch element connects the power output end of power end and described DC-DC constant current unit by divider resistance R1, the second end ground connection of described second switch element, described divider resistance R2 is connected between the control end and ground of described second switch element, described voltage stabilizing didoe ZD1 is connected between the control end and ground of described second switch element, the first termination LED negative pole of described second switch element, described divider resistance R3 and divider resistance R4 are serially connected between first end and ground of described second switch element, the control termination divider resistance R3 of described first switch element and the public connecting end of divider resistance R4, described inductance C1 is connected between the control end and ground of first switch element, the second end ground connection of described first switch element, first end of described first switch element connect the PWM control end of described DC-DC constant current unit by divider resistance R5.
Fig. 1 shows the circuit structure of the led drive circuit that the embodiment of the invention provides, and for convenience of explanation, only shows the part relevant with the embodiment of the invention, and details are as follows.
Led drive circuit generally includes DC-DC constant current unit 100, driving output unit 200 and the LED that links to each other successively; DC-DC constant current unit 100 connects DC power supply; drive output unit 200 and connect the LED positive pole; led drive circuit also comprises short-circuit protection circuit 300, and short-circuit protection circuit 300 comprises:
The control end of second switch element 302 meets the power output end OUT of power end VCC and DC-DC constant current unit 100 by divider resistance R1, the second end ground connection of second switch element 302, divider resistance R2 is connected between the control end and ground of second switch element 302, voltage stabilizing didoe ZD1 is connected between the control end and ground of second switch element 302, the first termination LED negative pole of second switch unit 302, divider resistance R3 and divider resistance R4 are serially connected between first end and ground of second switch element 302, the control termination divider resistance R3 of first switch element 301 and the public connecting end of divider resistance R4, inductance C1 is connected between the control end and ground of the first switch unit 301, the second end ground connection of first switch element 301, first end of the first switch unit 301 meet the PWM control end PWM of DC-DC constant current unit 100 by divider resistance R5.
As one embodiment of the invention, first switch element 301 is triode Q1, the base stage of triode Q1 is the control end of first switch element 301, and the current collection of triode Q1 is first end of the first switch unit 301 very, and the emission of triode Q1 is second end of first switch element 301 very.
As one embodiment of the invention, second switch element 302 is metal-oxide-semiconductor Q2, the grid of metal-oxide-semiconductor Q2 is the control end of second switch element 302, and the drain electrode of metal-oxide-semiconductor Q2 is first end of second switch element 302, and the source electrode of metal-oxide-semiconductor Q2 is second end of second switch unit 302.
The operation principle of short-circuit protection circuit 300 is:
When the output loading short circuit; control end moment of triode Q1 adds high level, causes triode Q1 conducting, and the PWM control end of DC-DC constant current unit is by triode Q1 ground connection; cause the output of DC-DC constant current unit to be turn-offed, thereby realize the function of load short circuits protection.
In embodiments of the present invention; when the output loading short circuit; control end moment of first switch element adds high level; cause the first switch element conducting; the PWM control end of DC-DC constant current unit is by the first switch element ground connection; cause the output of DC-DC constant current unit to be turn-offed, thereby realize the function of load short circuits protection.
The above only is preferred embodiment of the present invention, not in order to restriction the present invention, all any modifications of being done within the spirit and principles in the present invention, is equal to and replaces and improvement etc., all should be included within protection scope of the present invention.
Claims (6)
1. the short-circuit protection circuit of a led drive circuit connects DC-DC constant current unit and LED negative pole respectively, it is characterized in that described short-circuit protection circuit comprises:
First switch element, second switch element, divider resistance R1, divider resistance R2, divider resistance R3, divider resistance R4, divider resistance R5, voltage stabilizing didoe ZD1 and inductance C1;
The control end of described second switch element connects the power output end of power end and described DC-DC constant current unit by divider resistance R1, the second end ground connection of described second switch element, described divider resistance R2 is connected between the control end and ground of described second switch element, described voltage stabilizing didoe ZD1 is connected between the control end and ground of described second switch element, the first termination LED negative pole of described second switch element, described divider resistance R3 and divider resistance R4 are serially connected between first end and ground of described second switch element, the control termination divider resistance R3 of described first switch element and the public connecting end of divider resistance R4, described inductance C1 is connected between the control end and ground of first switch element, the second end ground connection of described first switch element, first end of described first switch element connect the PWM control end of described DC-DC constant current unit by divider resistance R5.
2. short-circuit protection circuit as claimed in claim 1; it is characterized in that; described first switch element is triode Q1; the base stage of described triode Q1 is the control end of first switch element; the current collection of described triode Q1 is first end of first switch element very, and the emission of described triode Q1 is second end of first switch element very.
3. short-circuit protection circuit as claimed in claim 1; it is characterized in that; described second switch element is metal-oxide-semiconductor Q2; the grid of described metal-oxide-semiconductor Q2 is the control end of second switch element; the drain electrode of described metal-oxide-semiconductor Q2 is first end of second switch element, and the source electrode of described metal-oxide-semiconductor Q2 is second end of second switch element.
4. a led drive circuit comprises DC-DC constant current unit, drives output unit and LED, it is characterized in that described led drive circuit also comprises short-circuit protection circuit, and described short-circuit protection circuit comprises:
First switch element, second switch element, divider resistance R1, divider resistance R2, divider resistance R3, divider resistance R4, divider resistance R5, voltage stabilizing didoe ZD1 and inductance C1;
The control end of described second switch element connects the power output end of power end and described DC-DC constant current unit by divider resistance R1, the second end ground connection of described second switch element, described divider resistance R2 is connected between the control end and ground of described second switch element, described voltage stabilizing didoe ZD1 is connected between the control end and ground of described second switch element, the first termination LED negative pole of described second switch element, described divider resistance R3 and divider resistance R4 are serially connected between first end and ground of described second switch element, the control termination divider resistance R3 of described first switch element and the public connecting end of divider resistance R4, described inductance C1 is connected between the control end and ground of first switch element, the second end ground connection of described first switch element, first end of described first switch element connect the PWM control end of described DC-DC constant current unit by divider resistance R5.
5. led drive circuit as claimed in claim 4, it is characterized in that, described first switch element is triode Q1, the base stage of described triode Q1 is the control end of first switch element, the current collection of described triode Q1 is first end of first switch element very, and the emission of described triode Q1 is second end of first switch element very.
6. led drive circuit as claimed in claim 4, it is characterized in that, described second switch element is metal-oxide-semiconductor Q2, the grid of described metal-oxide-semiconductor Q2 is the control end of second switch element, the drain electrode of described metal-oxide-semiconductor Q2 is first end of second switch element, and the source electrode of described metal-oxide-semiconductor Q2 is second end of second switch element.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011100895408A CN102231511A (en) | 2011-04-11 | 2011-04-11 | LED drive circuit and short-circuit protection circuit thereof |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011100895408A CN102231511A (en) | 2011-04-11 | 2011-04-11 | LED drive circuit and short-circuit protection circuit thereof |
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| CN102231511A true CN102231511A (en) | 2011-11-02 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN2011100895408A Pending CN102231511A (en) | 2011-04-11 | 2011-04-11 | LED drive circuit and short-circuit protection circuit thereof |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102855860A (en) * | 2012-09-26 | 2013-01-02 | 深圳Tcl新技术有限公司 | LED (light-emitting diode) drive circuit and liquid crystal display |
| CN103401209A (en) * | 2013-08-02 | 2013-11-20 | 广州视源电子科技股份有限公司 | LED (light emitting diode) backlight short-circuit protection circuit |
| CN104343669A (en) * | 2013-07-25 | 2015-02-11 | 珠海格力电器股份有限公司 | Compressor overload protection system |
| CN105429120A (en) * | 2015-11-19 | 2016-03-23 | 广州中逸光电子科技有限公司 | Surge current suppression circuit |
| CN107370117A (en) * | 2017-07-11 | 2017-11-21 | 深圳金三立视频科技股份有限公司 | A kind of output overcurrent and short-circuit protection circuit and a kind of electronic equipment |
| WO2018126495A1 (en) * | 2017-01-04 | 2018-07-12 | 深圳市华星光电技术有限公司 | Led backlight driving circuit and liquid crystal display |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101959352A (en) * | 2010-10-15 | 2011-01-26 | 上海小糸车灯有限公司 | LED driving circuit with LED short-circuit protection |
| CN202004436U (en) * | 2011-04-11 | 2011-10-05 | 深圳桑达国际电子器件有限公司 | Light emitting diode (LED) driving circuit and short circuit protection circuit thereof |
-
2011
- 2011-04-11 CN CN2011100895408A patent/CN102231511A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101959352A (en) * | 2010-10-15 | 2011-01-26 | 上海小糸车灯有限公司 | LED driving circuit with LED short-circuit protection |
| CN202004436U (en) * | 2011-04-11 | 2011-10-05 | 深圳桑达国际电子器件有限公司 | Light emitting diode (LED) driving circuit and short circuit protection circuit thereof |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102855860A (en) * | 2012-09-26 | 2013-01-02 | 深圳Tcl新技术有限公司 | LED (light-emitting diode) drive circuit and liquid crystal display |
| CN102855860B (en) * | 2012-09-26 | 2015-04-22 | 深圳Tcl新技术有限公司 | LED (light-emitting diode) drive circuit and liquid crystal display |
| CN104343669A (en) * | 2013-07-25 | 2015-02-11 | 珠海格力电器股份有限公司 | Compressor overload protection system |
| CN104343669B (en) * | 2013-07-25 | 2016-12-28 | 珠海格力电器股份有限公司 | A kind of overload of compressor protection system |
| CN103401209A (en) * | 2013-08-02 | 2013-11-20 | 广州视源电子科技股份有限公司 | LED (light emitting diode) backlight short-circuit protection circuit |
| CN103401209B (en) * | 2013-08-02 | 2016-04-27 | 广州视源电子科技股份有限公司 | LED-backlit short-circuit protection circuit |
| CN105429120A (en) * | 2015-11-19 | 2016-03-23 | 广州中逸光电子科技有限公司 | Surge current suppression circuit |
| WO2018126495A1 (en) * | 2017-01-04 | 2018-07-12 | 深圳市华星光电技术有限公司 | Led backlight driving circuit and liquid crystal display |
| CN107370117A (en) * | 2017-07-11 | 2017-11-21 | 深圳金三立视频科技股份有限公司 | A kind of output overcurrent and short-circuit protection circuit and a kind of electronic equipment |
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Application publication date: 20111102 |