CN108391347B - Dimming circuit for LED driving - Google Patents
Dimming circuit for LED driving Download PDFInfo
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- CN108391347B CN108391347B CN201810325536.9A CN201810325536A CN108391347B CN 108391347 B CN108391347 B CN 108391347B CN 201810325536 A CN201810325536 A CN 201810325536A CN 108391347 B CN108391347 B CN 108391347B
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- 239000003990 capacitor Substances 0.000 claims description 14
- 230000015556 catabolic process Effects 0.000 claims description 11
- 230000008859 change Effects 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 238000005286 illumination Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
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- 230000004044 response Effects 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
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Abstract
The invention discloses a dimming circuit for LED driving, which comprises a voltage stabilizing unit and a voltage dividing unit, and has the advantages of simple circuit, high dimming performance, extremely low cost and convenient debugging, when no dimming signal is input at the input end of an external dimming signal source, the circuit can provide a constant dimming signal for a dimming driver, when the dimming signal is input at the input end of the dimming signal source, the on-off of the voltage stabilizing tube can be controlled according to the input condition of the dimming signal, and the voltage dividing ratio of the voltage dividing unit is changed, so that the dimming signal with different sizes is provided for the dimming driver.
Description
Technical Field
The invention relates to the technical field of lamp dimming, in particular to a dimming circuit for LED driving.
Background
With the development of LED technology, LED illumination is more and more widely spread in modern society, and LED is taken as a new light source which is attractive in the 21 st century, and gradually takes up important roles in various fields, and has wide prospects in the fields of illumination and display, especially white light LED which is widely researched now is developed into a main green light source which can replace incandescent lamps and fluorescent lamps due to the advantages of small size, shock resistance, high response speed, good directivity, long service life which is tens of thousands of hours, light color approaching to incandescent lamps, low-voltage driving, no pollution of pumps and lead and the like.
The high-performance dimming circuit in the prior art is realized by adopting an integrated circuit, the circuit is originally complex, a plurality of devices are used, the debugging difficulty is high, the production and manufacturing cost is high, the dimming performance of the dimming circuit with a simple circuit is rough, and the dimming reliability is poor.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and designs a dimming circuit for LED driving, which has the advantages of simple circuit principle, good dimming performance and extremely low cost.
In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:
the dimming circuit for LED driving comprises a voltage stabilizing unit and a voltage dividing unit, wherein the output end of the voltage stabilizing unit is connected with the input end of the voltage dividing unit through a current limiting resistor R7; the input end of the voltage dividing unit is sequentially connected with the resistor R4 and the positive end of the diode D2 in series, the negative end of the diode D2 is used as a dimming signal source input end, the output end of the voltage dividing unit is used as a dimming voltage output end, and the voltage dividing unit is directly connected with the reference signal input end of the dimming driver; when the dimming signal is not input to the input end of the dimming signal source, the voltage dividing unit outputs constant dimming voltage according to the constant voltage provided by the voltage stabilizing unit; when the dimming signal is input to the input end of the dimming signal source, the voltage division unit changes the voltage division of the dimming signal according to the size of the dimming signal so as to output dimming voltages with different voltage values.
Preferably, the voltage dividing unit includes a voltage stabilizing tube ZD2, a resistor R8, a resistor R9A, a resistor R9B, a resistor R10, a diode D4, a diode D5 and a capacitor C3, where the voltage stabilizing tube ZD2 is connected in series with the resistor R10 and then connected in parallel with the resistor R8, a node between the resistor R8 and the resistor R10 is respectively connected to the negative terminal of the diode D4, the negative terminal of the diode D5 and the first terminal of the resistor R9A, the positive terminal of the diode D4 is connected in series with the capacitor C3 and then grounded, the positive terminal of the diode D5 and the second terminal of the resistor R9A are both grounded, the resistor R9B is connected in parallel with the diode D4, and a node between the diode D4 and the capacitor C3 is connected to the dimming voltage output terminal.
Preferably, the voltage stabilizing unit comprises a voltage stabilizing tube ZD1 and a resistor R6, the positive electrode of the voltage stabilizing tube ZD1 is grounded, the negative electrode is connected in series with the resistor R6, the other end of the resistor R6 is connected with a direct-current voltage input end, and a node between the voltage stabilizing tube ZD1 and the resistor R6 is connected with the second end of the resistor R7.
Preferably, the reverse breakdown voltage of the voltage regulator ZD1 is greater than the reverse breakdown voltage of the voltage regulator ZD 2.
Preferably, the voltage range of the dimming signal source is 0-10V.
Preferably, the maximum voltage value of the dimming signal source is smaller than the reverse breakdown voltage of the regulator ZD 1.
The invention has the positive beneficial effects that: the dimming circuit for LED driving has the advantages of simple circuit, high dimming performance, extremely low cost and convenient debugging, when no dimming signal is input at the input end of the dimming signal source, constant dimming current is provided for the dimming driver, when the dimming signal is input at the input end of the dimming signal source, the on-off of the voltage stabilizing tube is controlled according to the input condition of the dimming signal, so that the voltage division of the circuit is changed, and different dimming voltages are provided for the dimming driver.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic circuit diagram of a dimming circuit according to the present invention.
Fig. 2 is a circuit diagram of the dimming driving controller.
The specific meanings of the reference numerals in the drawings are: 1 is a voltage division unit, 2 is a voltage stabilizing unit, DIM+ is a dimming signal source input end, and DIM is a dimming voltage output end.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the present invention more apparent, the present invention is described below by means of specific embodiments shown in the accompanying drawings. It should be understood that the description is only illustrative and is not intended to limit the scope of the invention. In addition, in the following description, descriptions of well-known structures and techniques are omitted so as not to unnecessarily obscure the present invention.
The following describes the embodiment of the present invention in detail with reference to fig. 1 and 2.
The dimming circuit for LED driving is used for providing a reference signal for a dimming driver, the dimming driver compares the current brightness signal of an LED light source with the reference signal, and the driver output current is adjusted according to the comparison result to change the brightness of the light source. When the dimming signal source input end DIM+ of the dimming circuit is input with no dimming signal, a constant dimming current is provided for the dimming driver of the dimming circuit, so that the dimming driver outputs full current; when the dimming signal is input from the dim+ input end of the dimming signal source, the on-off of the voltage stabilizing tube is controlled according to the input condition of the dimming signal so as to change the voltage division of the circuit, thereby providing dimming voltages with different magnitudes for the dimming driver and enabling the dimming driver to output corresponding dimming current. Therefore, under the condition of simplifying a circuit, the dimming performance of the invention can be ensured, the dimming reliability is ensured, the dimming depth is improved, the dimming precision of a low end is ensured, and the production cost of enterprises is reduced.
The dimming circuit for LED driving has a dimming signal source input end DIM+ and a dimming voltage output end DIM, wherein the dimming voltage output end DIM is connected with a reference signal input end of a dimming driver.
As shown in fig. 2, the dimming driver is a driving control chip with eight pins, and the names and functions of the pins are shown in the following table:
the dimming voltage output end DIM of the dimming circuit is connected with the dimming signal input end DIM (reference signal input end) of the dimming driver, and the dimming current output end of the dimming driver outputs dimming current to drive the LED to emit light.
Specifically, as shown in fig. 1, the dimming circuit of the present invention comprises a voltage stabilizing unit 2 and a voltage dividing unit 1, wherein the output end of the voltage stabilizing unit is connected with the input end of the voltage dividing unit through a current limiting resistor R7; the input end of the voltage dividing unit is sequentially connected with the resistor R4 and the positive end of the diode D2 in series, the negative end of the diode D2 is used as a dimming signal source input end DIM+, and the output end of the voltage dividing unit is used as a dimming voltage output end DIM and is directly connected with the reference signal input end of the dimming driver.
When the dimming signal is not input to the dim+ input terminal of the dimming signal source, the voltage dividing unit 1 outputs a constant dimming signal according to the constant voltage provided by the voltage stabilizing unit 2; when the dimming signal is input at the dim+ input terminal of the dimming signal source, the voltage dividing unit 1 changes the voltage dividing ratio according to the magnitude of the dimming signal so as to output the dimming voltages with different voltage values. The dimming voltage output by the voltage division unit is transmitted to a dimming driver, and the dimming driver outputs current corresponding to the dimming voltage to drive the LED to emit light. In this embodiment, the larger the current output by the dimming driver, the brighter the LED light source.
The voltage stabilizing unit 2 comprises a voltage stabilizing tube ZD1 and a resistor R6, wherein the positive electrode of the voltage stabilizing tube ZD1 is grounded, the negative electrode is connected with the resistor R6 in series, and the other end of the resistor R6 is connected with the direct-current voltage input end. The node between the voltage stabilizing tube ZD1 and the resistor R6 is connected with the resistor R7.
The voltage division unit 1 comprises a voltage stabilizing tube ZD2, a resistor R8, a resistor R9A, a resistor R9B, a resistor R10, a diode D4, a diode D5 and a capacitor C3. The voltage stabilizing tube ZD2 is connected with the resistor R10 in series and then connected with the resistor R8 in parallel, and a node between the negative end of the voltage stabilizing tube ZD2 and the resistor R8 is connected to the signal input end of the voltage dividing unit. The node between the resistor R8 and the resistor R10 is respectively connected with the negative electrode end of the diode D4, the negative electrode end of the diode D5 and the first end of the resistor R9A, the positive electrode end of the diode D4 is connected with the capacitor C3 in series and then grounded, the positive electrode end of the diode D5 and the second end of the resistor R9A are grounded, the resistor R9B is connected with the diode D4 in parallel, and the node between the diode D4 and the capacitor C3 is connected to the dimming voltage output end.
The voltage range of the dimming signal source is 0-10V, and the maximum voltage value of the dimming signal source is smaller than the reverse breakdown voltage of the voltage stabilizing tube ZD 1. The reverse breakdown voltage of the regulator tube ZD1 is greater than the reverse breakdown voltage of the regulator tube ZD 2.
When the dimming signal is not input to the input end (dim+ port) of the dimming signal source, as shown in fig. 1, the 12V dc voltage input to the input end of the voltage stabilizing unit can make the voltage stabilizing tube ZD1 break down reversely, so that a 12V voltage is provided to the voltage dividing unit and the resistor R7 through the voltage stabilizing tube ZD1, and since the reverse breakdown voltage of the voltage stabilizing tube ZD1 is greater than the reverse breakdown voltage of the voltage stabilizing tube ZD2, the voltage stabilizing tube ZD2 is also turned on, the resistor R7, the resistor R8, the resistor R9A, the resistor R9B and the resistor R10 are divided together, so that the dimming voltage output end (DIM pin) of the dimming circuit can provide a constant voltage signal to the dimming driver, in this embodiment, a 3V voltage is provided to the dimming driver, and the dimming driver converts the voltage signal into a current signal, so that full light, i.e. full current is output.
When the dimming signal source input end (DIM+ port) is provided with the dimming signal input, the voltage stabilizing unit does not work. If the dimming voltage value input by the dim+ pin is greater than 5.1V, the voltage stabilizing tube ZD2 is turned on, a reverse current passes through, ZD2 and R10 together form an equivalent resistor, the equivalent resistor is connected in parallel with R8, and then is divided with R9 (R9A and R9B) after being connected in parallel, the dimming voltage output end (DIM pin) can provide a voltage signal for the dimming driver, and the dimming driver correspondingly outputs a dimming current according to the received voltage signal, so that the brightness of the LED light source is changed. When the dimming voltage value input from the DIM+ pin is smaller than 5.1V, the voltage stabilizing tube ZD2 is not conducted, the branch where the voltage stabilizing tube ZD2 is located is broken, at the moment, the voltage is divided through the R8 and the resistor R9, the DIM pin can provide a voltage signal with another voltage value for the dimming control chip, and the dimming driver correspondingly outputs current with another magnitude according to the received voltage signal, so that the brightness of the LED light source is changed.
Therefore, the LED light source dimming circuit can control the on-off of the voltage stabilizing tube according to the input condition of the dimming signal, so as to provide dimming voltages with different magnitudes for the dimming driver of the voltage stabilizing tube, and change the brightness of the LED light source. Under the conditions of simplifying the circuit and reducing the cost, the dimming performance and the dimming reliability of the circuit can be ensured, so that the debugging of the circuit is simpler.
When the dimming circuit does not work, R9, D4 and C3 form a loop, the capacitor C3 discharges, and a voltage is stably provided for the DIM pin, so that the dimming circuit is not easy to be disturbed. Specifically, when the voltage across the capacitor C3 is greater than the turn-on voltage of the diode D4, D4 is turned on, R9A, D4, C3 form a loop, and the capacitor C3 discharges; when the voltage at two ends of the capacitor C3 is smaller than the conducting voltage of the diode D4, the diode D4 is not conducted, the R9A, R9B, C3 forms a loop, the capacitor C3 discharges, and a voltage is stably provided for the DIM pin, so that the diode is not easy to be disturbed.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention and not for limiting the same; while the invention has been described in detail with reference to the preferred embodiments, those skilled in the art will appreciate that; modifications may be made to the specific embodiments of the present invention or equivalents may be substituted for part of the technical features thereof; without departing from the spirit of the invention, it is intended to cover the scope of the invention as claimed.
Claims (4)
1. The dimming circuit for LED driving is characterized by comprising a voltage stabilizing unit and a voltage dividing unit, wherein the output end of the voltage stabilizing unit is connected with one input end of the voltage dividing unit through a current limiting resistor R7; the other input end of the voltage dividing unit is sequentially connected with the resistor R4 and the positive end of the diode D2 in series, the negative end of the diode D2 is used as a dimming signal source input end, the output end of the voltage dividing unit is used as a dimming voltage output end and is directly connected with the reference signal input end of a dimming driver, and the dimming current output end of the dimming driver outputs dimming current to drive the LED to emit light;
when the dimming signal is not input to the input end of the dimming signal source, the voltage dividing unit outputs constant dimming voltage according to the constant voltage provided by the voltage stabilizing unit; when the dimming signal is input from the input end of the dimming signal source, the voltage division unit changes the voltage division of the dimming signal according to the size of the dimming signal so as to output dimming voltages with different voltage values;
the voltage dividing unit comprises a voltage stabilizing tube ZD2, a resistor R8, a resistor R9A, a resistor R9B, a resistor R10, a diode D4, a diode D5 and a capacitor C3, wherein the voltage stabilizing tube ZD2 is connected with the resistor R10 in series and then connected with the resistor R8 in parallel, a node between the resistor R8 and the resistor R10 is respectively connected with the negative end of the diode D4, the negative end of the diode D5 and the first end of the resistor R9A, the positive end of the diode D4 is connected with the capacitor C3 in series and then grounded, the positive end of the diode D5 and the second end of the resistor R9A are both grounded, the resistor R9B is connected with the diode D4 in parallel, and a node between the diode D4 and the capacitor C3 is connected to the dimming voltage output end;
the voltage stabilizing unit comprises a voltage stabilizing tube ZD1 and a resistor R6, wherein the positive electrode of the voltage stabilizing tube ZD1 is grounded, the negative electrode is connected with the resistor R6 in series, the other end of the resistor R6 is connected with a direct-current voltage input end, and a node between the voltage stabilizing tube ZD1 and the resistor R6 is connected with the second end of the resistor R7.
2. The dimming circuit for LED driving according to claim 1, wherein the reverse breakdown voltage of the regulator tube ZD1 is greater than the reverse breakdown voltage of the regulator tube ZD 2.
3. A dimming circuit for LED driving as claimed in claim 1, wherein the voltage range of the dimming signal source is 0-10V.
4. A dimming circuit for LED driving as claimed in claim 3, wherein the maximum voltage value of the dimming signal source is less than the reverse breakdown voltage of the regulator ZD 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810325536.9A CN108391347B (en) | 2018-04-12 | 2018-04-12 | Dimming circuit for LED driving |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810325536.9A CN108391347B (en) | 2018-04-12 | 2018-04-12 | Dimming circuit for LED driving |
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| CN108391347A CN108391347A (en) | 2018-08-10 |
| CN108391347B true CN108391347B (en) | 2023-12-15 |
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| CN201810325536.9A Active CN108391347B (en) | 2018-04-12 | 2018-04-12 | Dimming circuit for LED driving |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104684155A (en) * | 2013-11-28 | 2015-06-03 | 深圳市海洋王照明工程有限公司 | LED (light emitting diode) driving power supply dimming circuit and lamp |
| CN104902653A (en) * | 2015-06-24 | 2015-09-09 | 赛尔富电子有限公司 | LED constant-voltage dimming power supply and LED lamp dimming system |
| CN204887597U (en) * | 2015-08-06 | 2015-12-16 | 上海阿卡得电子有限公司 | Preventing arcing circuit of LED fluorescent tube |
| CN205017630U (en) * | 2015-06-25 | 2016-02-03 | 英飞特电子（杭州）股份有限公司 | LED drive power supply adjusts luminance and turn -offs control circuit |
| CN105682298A (en) * | 2016-03-29 | 2016-06-15 | 深圳市实益达照明有限公司 | Led driving power supply |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9491815B2 (en) * | 2013-10-02 | 2016-11-08 | Microsemi Corporation | LED luminaire driving circuit and method |
| CN208046974U (en) * | 2018-04-12 | 2018-11-02 | 上海阿卡得电子有限公司 | A kind of light adjusting circuit for LED drivings |
-
2018
- 2018-04-12 CN CN201810325536.9A patent/CN108391347B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104684155A (en) * | 2013-11-28 | 2015-06-03 | 深圳市海洋王照明工程有限公司 | LED (light emitting diode) driving power supply dimming circuit and lamp |
| CN104902653A (en) * | 2015-06-24 | 2015-09-09 | 赛尔富电子有限公司 | LED constant-voltage dimming power supply and LED lamp dimming system |
| CN205017630U (en) * | 2015-06-25 | 2016-02-03 | 英飞特电子（杭州）股份有限公司 | LED drive power supply adjusts luminance and turn -offs control circuit |
| CN204887597U (en) * | 2015-08-06 | 2015-12-16 | 上海阿卡得电子有限公司 | Preventing arcing circuit of LED fluorescent tube |
| CN105682298A (en) * | 2016-03-29 | 2016-06-15 | 深圳市实益达照明有限公司 | Led driving power supply |
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| Publication number | Publication date |
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| CN108391347A (en) | 2018-08-10 |
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