CN102647077A - RCD (Resistance Capacitor Diode) absorption circuit, dimmable LED (Light-Emitting Diode) power supply system and dimming method - Google Patents
RCD (Resistance Capacitor Diode) absorption circuit, dimmable LED (Light-Emitting Diode) power supply system and dimming method Download PDFInfo
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- CN102647077A CN102647077A CN2011100409645A CN201110040964A CN102647077A CN 102647077 A CN102647077 A CN 102647077A CN 2011100409645 A CN2011100409645 A CN 2011100409645A CN 201110040964 A CN201110040964 A CN 201110040964A CN 102647077 A CN102647077 A CN 102647077A
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Abstract
The invention relates to a RCD (Resistance Capacitor Diode) absorption circuit, a dimmable LED (Light-Emitting Diode) power supply system using the circuit and a dimming method. The RCD absorption circuit comprises a first resistor, a capacitor and a diode, wherein the first resistor is connected with the capacitor in parallel and then is connected with the diode in series; one end of the first resistor connected with the capacitor in parallel is connected with the cathode of the diode, and the other end of the first resistor forms a first terminal of the RCD absorption circuit; and the anode of the diode forms a second terminal of the RCD absorption circuit. The RCD absorption circuit is characterized in that the RCD absorption circuit also comprises a RCD absorption circuit power regulating component connected with the first resistor and the capacitor in parallel. The RCD absorption circuit has the beneficial effects that a dimmer of the absorption circuit is used to change the power transmitted to the output end in starting, so that the output current of multiple groups of LED lighting driving power supplies can achieve a consistent effect, and LEDs can simultaneously and consistently emit light.
Description
Technical field
The present invention relates to Dimmable light-emitting diode (LED) illumination driving power source system and light-dimming method.Specifically, relate to a plurality of LED illumination driving power source systems that use same triode ac switch (TRIAC) dimmer to carry out light modulation.
Background technology
Along with the development of technology, the light efficiency of LED improves constantly, and more and more users is used the LED illumination.A plurality of LED illumination driving powers use the technology of same dimmer to use more and more at large.Common dimmer comprises the TRIAC dimmer.
Fig. 1 is the fundamental diagram that utilizes the TRIAC dimmer that a plurality of LED illumination driving power source systems are carried out light modulation.LED illumination driving power comprises inverse-excitation type switch power-supply.Wherein, a plurality of LED illumination driving powers are connected in parallel to each other, and are connected with power supply with TRIAC dimmer series connection back.Wherein the TRIAC dimmer is used to regulate the angle of flow of AC-input voltage, thereby makes the LED illumination driving power of its connection have dimming function.LED illumination driving power is AC-DC LED illumination driving power, and the TRIAC dimmer is connected the hot side (L) of input, and LED illumination driving power is connected between TRIAC dimmer and the zero line (N).The problems of the prior art are that each LED that organizes the driving of LED illumination driving power starts inconsistent.
Now with regard to the course of work of LED illumination driving power and start inconsistent reason and describe.Along with the change at TRIAC dimmer conduction angle, main line voltage also changes thereupon.When main line voltage changes from small to large; When in case main line voltage is elevated to the operating voltage of main control integrated circuit (IC) of LED illumination driving power; LED illumination driving power is started working; The output voltage of respectively organizing LED illumination driving power this moment does not reach the starting resistor of led light source, and LED is not luminous.When increasing gradually along with the angle of flow of regulating TRIAC; Input main line voltage also raises gradually, and when output voltage reaches the starting resistor of led light source, LED begins luminous; LED illumination this moment driving power still is operated in open loop situations, and the output current feedback control circuit is inoperative.When continuing to increase the angle of flow increase main line voltage of TRIAC dimmer; Output current reaches the full-load current of LED gradually, and LED illumination driving power is operated in the closed loop state, and control circuit works; Can change output current through control circuit; The brightness of LED lamp reaches maximum, this moment no matter the angle of flow of TRIAC what increases for another example, the brightness of LED can not change.But; When a plurality of LED illumination driving powers as shown in Figure 1 use same TRIAC dimmer; When LED illumination driving power was operated in open loop situations, because the component parameters in the LED illumination driving power is inconsistent, the circuit loss that causes was inconsistent; Thereby cause actual transmission power inconsistent, output current is inconsistent.In view of directly perceived; The LED that this inconsistent LED illumination driving power that causes having drives is earlier bright, and is bright behind the LED that the LED illumination driving power that has drives, and the startup of promptly respectively organizing the LED that LED illumination driving power drives is inconsistent; In addition, the brightness of LED is also inconsistent.
Fig. 2 is the circuit diagram that absorbs circuit in the prior art in the LED illumination driving power.Wherein this absorption circuit is resistance, electric capacity, diode (RCD) absorption circuit.It is parallelly connected with C1 that this RCD absorbs the resistance R 1 of circuit, and then connect with diode D1, connects the other end of the transformer T1 (not shown) that is connected with the output of LED illumination driving circuit after the end of transformer T1 and the above-mentioned element parallel connection with switching tube Q1.This RCD absorbs circuit and is connected with the full bridge rectifier (not shown).The function that RCD absorbs circuit is, in the time of reverse exciting switching voltage regulator work, when switching tube Q1 breaks off; Because there is leakage inductance in transformer; The leakage inductance of transformer can produce peak voltage, and RCD absorbs circuit can absorb this due to voltage spikes, thereby protection switch pipe Q1 is not broken down by high-voltage; Because if switching tube Q1 is breakdown, whole LED illumination driving power can't operate as normal.Underloading or the startup stage, it is main loss source that this RCD absorbs circuit.Because this absorption circuit does not have the effect of adjusting power output, the therefore existing LED that respectively organizes the driving of LED illumination driving power can't reach and start unanimity, the effect that brightness is consistent in the prior art.
Summary of the invention
To the problems referred to above; A kind of LED illumination driving power source system and light-dimming method that absorbs circuit that comprise here described; Its overcome a plurality of LED illumination driving powers start inconsistent and cause LED not luminous simultaneously with the inconsistent problem of luminosity; Make to use many groups LED illumination driving power of same dimmer can consistent output current, make LED simultaneously and as one man luminous.
For this reason; The invention discloses a kind of RCD and absorb circuit; Comprise first resistance, electric capacity and diode, wherein connect with diode after first resistance and the electric capacity parallel connection that first resistance links to each other with the negative pole of diode with an end of electric capacity parallel connection; The other end constitutes first terminals that RCD absorbs circuit, and the positive pole of diode constitutes second terminals that RCD absorbs circuit; Said RCD absorbs circuit and comprises that also the RCD parallelly connected with said first resistance and said electric capacity absorbs circuit power and regulate parts.
The invention also discloses a kind of Dimmable LED power-supply system, it is controlled by dimmer, and this system comprises: at least one LED illumination driving power circuit; Wherein each said LED illumination driving power circuit comprises: the AC-to DC converter, and it cooperates with dimmer; Transformer is used for the effect of energy storage and voltage of transformation; Output is used for the effect of rectifying and wave-filtering, supplies power so that illumination to be provided to LED; And PWM controller and switching tube, be used for output is controlled; Wherein said LED illumination driving power circuit has been used RCD of the present invention and has been absorbed circuit, and wherein first terminals link to each other with the two ends of transformer importation respectively with second terminals and first terminals link to each other with the output of AC-to DC converter.
The invention still further relates to a kind of light-dimming method that utilizes dimmer that LED illumination driving power is carried out; Be included in the disclosed RCD absorption of the present invention circuit is set in the LED illumination driving power; As reference power supply, according to this reference power supply dimmer is adjusted to certain angle of flow, with a LED illumination driving power when output current is full-load current about 1%; Fixing this angle of flow; Utilize this angle of flow that LED illumination driving power to be measured is tested, regulate RCD and absorb the power adjusting section in the circuit, make through the output current of LED illumination diode consistent.
Beneficial effect of the present invention is; Used the LED illumination driving power circuit of this absorption circuit can change the power that is transferred to output when starting; Reach and make that many group LED illumination driving power output currents can consistent effect, make that LED can be simultaneously and as one man luminous.
Description of drawings
Accompanying drawing is only started from illustrated purpose, yet, through with reference to the following detailed that combines appended accompanying drawing to carry out, can understand the present invention itself better, wherein:
Fig. 1 is the fundamental diagram that utilizes the TRIAC dimmer that a plurality of LED illumination driving power source systems are carried out light modulation.
Fig. 2 is the circuit diagram that absorbs circuit in the prior art in the LED illumination driving power.
Fig. 3 is the circuit diagram that absorbs circuit according to the RCD of first embodiment of the invention.
Fig. 4 is the circuit diagram that absorbs circuit according to the RCD of second embodiment of the invention.
Fig. 5 is the TRIAC dimmer and an example LED illumination driving power circuit figure according to second embodiment of the invention.
Embodiment
Can not accomplish under the on all four situation in the parameter of element; The present invention comes control transmission power from regulating circuit loss aspect; Change because inconsistent, the inconsistent defective of brightness of the inconsistent startup that brings of circuit loss starts consistent, the consistent technique effect of brightness thereby reach.In inverse-excitation type switch power-supply, the element that loss is bigger is that switch MOS pipe, transformer, secondary commutation diode, RCD absorb circuit.Therefore, the present invention mainly absorbs circuit from changing RCD, makes it to have the function of regulating power and start with.
Fig. 3 is the circuit diagram that absorbs circuit according to the RCD of first embodiment of the invention.Wherein, The variable resistance VR1 that this RCD absorbs circuit and resistance R 1, capacitor C 1 are parallelly connected; And then connect with diode D1; Promptly variable resistance VR1, resistor R 1 and the capacitor C 1 of parallel connection are connected to the negative pole of diode D1; Connect with switching tube Q1 after the end of transformer T1 and the parallel connection of above-mentioned quaternary part, promptly between the positive pole of the end of the transformer T1 variable resistance VR1, resistor R 1 and the capacitor C 1 that are connected parallel connection and diode D1, the other end of transformer T1 and the LED output of the driving power circuit (not shown) that is connected that throws light on.This RCD absorbs circuit and is connected with the full bridge rectifier (not shown).In the preferred execution mode of first embodiment of the invention, with variable resistance VR1 and the protective resistor R2 and the resistance R 1 of series connection, capacitor C 1 parallel connection.The function that RCD absorbs circuit is in order to absorb the due to voltage spikes on the switching tube Q1, and Q1 is not broken down by high-voltage with the protection switch pipe.The resistance range of variable resistance VR1 tens kilo-ohms of scopes to hundreds of kilo-ohm, is leakage inductance value, resistance R 1, capacitor C 1, the diode D1 component parameters according to transformer T1 generally, and LED illumination driving power error amount is confirmed.The protective resistor R2 that increases in the preferred implementation is in order to prevent the misoperation to variable resistance VR1, even variable resistance VR1 is 0 Europe by misoperation, also can not damage circuit.The value of protective resistor R2 is generally at tens kilo-ohms.And resistance R 1, capacitor C 1 and diode D1 are the existing discrete device commonly used in the circuit that absorbs.Switching tube Q1 is any device that can realize switching function, such as, field effect (MOS) pipe, triode.With depletion type N raceway groove isolated gate FET is example; The drain electrode of FET Q1 is connected to the positive pole of diode; The source electrode of FET Q1 is connected with the full bridge rectifier (not shown), and the grid of FET Q1 is connected to pulse-width modulation (PWM) control circuit (not shown) and is connected.The PWM controller is controlled through the output of feedback network illumination driving power circuit.
In the system of a plurality of LED illumination driving powers,, when a certain power initiation, during output current overgauge power supply, just reduce the resistance of variable resistance VR1 with LED illumination driving power reference power supply as a reference.Otherwise then increase the resistance of variable resistance VR1.The effect of variable resistance VR1 is to change the absorbed power that absorbs circuit, thereby changes the power that is transferred to output when starting.According to formula: P
In=P
Decrease+ P
o, wherein, P
InBe input power, P
DecreaseBe loss power, P
oBe power output.Usually input power is constant relatively, can reduce P through the size of regulating VR1
DecreaseThereby loss power guarantees that the difference between input power and the power output is less.The described RCD of this execution mode absorbs circuit and is particularly useful for following occasion: power output is less, and for example power output is less than the power supply of 15W; Or transformer T1 leakage inductance is little, and for example leakage inductance is less than the power supply of 15 μ H.
Fig. 4 is the circuit diagram that absorbs circuit according to the RCD of second embodiment of the invention.Transient state diode TVS of parallel connection again beyond the variable resistance VR1, resistance R 1, capacitor C 1 of parallel connection in execution mode as shown in Figure 3 wherein.Wherein the positive pole of transient state diode TVS is connected with the negative pole of diode D1, and the negative pole of transient state diode TVS is connected with resistance R 1, capacitor C 1 with the variable resistance VR1 of parallel connection.In the preferred execution mode of second embodiment of the invention, with variable resistance VR1 and the protective resistor R2 and the resistance R 1 of series connection, capacitor C 1 parallel connection.The overall operation principle and first execution mode of this RCD absorption circuit are similar.The parameter of the transient state diode TVS of extra increase is confirmed according to the size of leakage inductance and clamp voltage; When bearing a high-octane big pulse; Its working impedance is reduced to extremely low conduction value immediately, thereby allows big electric current to pass through, simultaneously voltage clamp at predeterminated level.When zero load and underloading, transient state diode TVS does not work; Diode D1, resistance R 1, protective resistance R2, variable resistance VR1, capacitor C 1 play clamp and change absorbed power; When heavy duty or being fully loaded with, transient state diode TVS plays clamping action, guarantees that due to voltage spikes can not damage switching tube Q1.The absorption circuit of this second execution mode is particularly useful for the big or big occasion of transformer T1 leakage inductance of power output, at this moment, capacitor C 1 can be suitably with the value of low capacity, thereby reduce loss.
Fig. 5 is the TRIAC dimmer and an example LED illumination driving power circuit figure according to second embodiment of the invention.Input is connected with A.C.-D.C. converter through the TRIAC dimmer; A.C.-D.C. converter is the full-bridge type rectification circuit preferably; Input voltage and input current behind over commutation gets into the primary circuit; And be connected with output through transformer secondary output, the end of output is connected with the LED illumination diode of one group of series connection.Wherein output carries out rectifying and wave-filtering to transformer coupled electric current and voltage of coming.RCD absorbs circuit and is connected primary.Wherein the PWM controller is in order to guarantee Switching Power Supply work, so any integrated circuit that can light modulation in this area is all passable, SSL2101 for example, 2102 etc.Pwm control circuit is connected to output through feedback network, and wherein feedback network is a feedback control loop, guarantees the stable of circuit.When just starting, less through the electric current of LED illumination diode, after the startup, through changing the angle of flow of TRIAC dimmer, voltage, the electric current of LED illumination diode can change size thereupon, just can change the brightness of LED.
More than the RCD of the two kinds of execution modes precision that absorbs resistance R 1, protective resistance R2 in the circuit be at least 1%, the precision of variable resistance VR1 is at least 10%, the precision of capacitor C 1 is higher than 10%.The value of resistance R 1 is generally greater than protective resistance R2, and the resistance R 1 of big value can guarantee the work of circuit.During startup; The same angle of flow at the TRIAC dimmer; And under the identical input voltage, improve scope fluctuation between less than 1 milliampere to 6 milliamperes of the output current of LED illumination driving power that RCD absorbs circuit (this scope is according to different output currents and difference, but common characteristic is a scope all very big) existing not containing; Output current when containing LED illumination driving power that above-mentioned improvement RCD absorbs circuit and starting promptly flows through LED among Fig. 5
1, LED
2On electric current, be stable at relatively-stationary value between the above-mentioned scope because the output current fluctuation scope is smaller, maintain output current rating I
o* 1% ± 20%, for example, when output current was 350mA, the outputting current steadily in the time of will starting on the engineering was in the 2.8-4.2mA scope, and the stable of output current guaranteed that the startup of LED is consistent, and brightness is consistent.
In addition, the present invention also provides a kind of method of utilizing this TRIAC dimmer control LED illumination driving power.Under the condition of identical input voltage, at first utilize standard items to regulate the TRIAC dimmer to certain angle of flow, make that output current is 1% of a full-load current, fixing this angle of flow.Then utilize this TRIAC dimmer to the LED driving power that throws light on, regulate VR1, make through the output current of LED illumination diode consistent.
Though illustrated and described specific embodiment here, one skilled in the art should be appreciated that, with described specific embodiment, and do not deviate from scope of the present invention shown in various changes and/or equivalent execution mode can substitute.Any modification or the modification of the specific embodiment that the present invention is intended to contain here and is discussed.For example, the formation cable that can the lead of method for preparing be intertwined for example utilizes UV mark and non-marked lead alternately.Therefore, the present invention is intended to only receive the restriction of claim and equivalent thereof.
Claims (10)
1. a RCD absorbs circuit; Comprise first resistance, electric capacity and diode; Wherein connect with diode after first resistance and the electric capacity parallel connection; First resistance links to each other with the negative pole of diode with an end of electric capacity parallel connection, and the other end constitutes first terminals that RCD absorbs circuit, and the positive pole of diode constitutes second terminals that RCD absorbs circuit; It is characterized in that said RCD absorbs circuit and comprises that also the RCD parallelly connected with said first resistance and said electric capacity absorbs circuit power and regulate parts.
2. RCD according to claim 1 absorbs circuit, it is characterized in that it is variable resistance that said RCD absorbs circuit power adjusting parts.
3. RCD according to claim 1 absorbs circuit, it is characterized in that said RCD absorbs circuit power and regulates second resistor and the variable resistance of parts for series connection.
4. RCD according to claim 2 absorbs circuit, the Standard resistance range that it is characterized in that said variable resistance be tens kilo-ohms to hundreds of kilo-ohm.
5. RCD according to claim 3 absorbs circuit, and it is not 0 Europe by misoperation with the protection variable resistance that the resistance that it is characterized in that second resistor is tens kilo-ohms.
6. absorb circuit according to the described RCD of one of claim 1-5; It is characterized in that this RCD absorbs circuit and comprises that also absorbing circuit power with RCD regulates the parallelly connected transient state diode of parts; The positive pole of said transient state diode is connected with second terminals, and negative pole first terminals of said transient state diode are connected.
7. Dimmable LED power-supply system, it is controlled by dimmer, and this system comprises:
At least one LED illumination driving power circuit; Wherein each said LED illumination driving power circuit comprises:
The AC-to DC converter, it cooperates with dimmer;
Transformer is used for the effect of energy storage and voltage of transformation;
Output is used for the effect of rectifying and wave-filtering, supplies power so that illumination to be provided to LED; And
PWM controller and switching tube are used for output is controlled;
It is characterized in that; Said LED illumination driving power circuit has been used like the described RCD of one of claim 1-6 and has been absorbed circuit, and wherein first terminals link to each other with the two ends of transformer importation respectively with second terminals and first terminals link to each other with the output of AC-to DC converter.
8. Dimmable LED power-supply system according to claim 7 is characterized in that said dimmer is the TRIAC dimmer.
9. Dimmable LED power-supply system according to claim 7 is characterized in that saidly connecting with the TRIAC dimmer after the parallel connection of one or more LED illumination driving power is arranged.
10. one kind is utilized dimmer to the light-dimming method that LED illumination driving power carries out, and comprising:
The RCD that in LED illumination driving power, is provided with like one of claim 1-6 absorbs circuit,
Throw light on driving power as reference power supply with a LED,
According to this reference power supply dimmer is adjusted to certain angle of flow,
When output current is full-load current about 1%, fixing this angle of flow,
Utilize this angle of flow that LED illumination driving power to be measured is tested,
Regulate RCD and absorb the power adjusting section in the circuit, make through the output current of LED consistent.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011100409645A CN102647077A (en) | 2011-02-18 | 2011-02-18 | RCD (Resistance Capacitor Diode) absorption circuit, dimmable LED (Light-Emitting Diode) power supply system and dimming method |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011100409645A CN102647077A (en) | 2011-02-18 | 2011-02-18 | RCD (Resistance Capacitor Diode) absorption circuit, dimmable LED (Light-Emitting Diode) power supply system and dimming method |
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| CN2011100409645A Pending CN102647077A (en) | 2011-02-18 | 2011-02-18 | RCD (Resistance Capacitor Diode) absorption circuit, dimmable LED (Light-Emitting Diode) power supply system and dimming method |
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Cited By (4)
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| CN104242656A (en) * | 2013-06-17 | 2014-12-24 | Abb研究有限公司 | Adaptive rcd snubber and method for switching converter |
| CN106230247A (en) * | 2016-09-28 | 2016-12-14 | 东莞铭普光磁股份有限公司 | A kind of self adaptation absorption system for Switching Power Supply and Switching Power Supply |
| CN106300946A (en) * | 2016-09-20 | 2017-01-04 | 深圳市华星光电技术有限公司 | A kind of absorbing circuit, power supply circuits and liquid crystal display |
| CN110266181A (en) * | 2018-03-12 | 2019-09-20 | 中兴通讯股份有限公司 | A kind of clamp circuit and clamp methods |
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN104242656A (en) * | 2013-06-17 | 2014-12-24 | Abb研究有限公司 | Adaptive rcd snubber and method for switching converter |
| CN106300946A (en) * | 2016-09-20 | 2017-01-04 | 深圳市华星光电技术有限公司 | A kind of absorbing circuit, power supply circuits and liquid crystal display |
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| CN106230247B (en) * | 2016-09-28 | 2019-05-28 | 东莞铭普光磁股份有限公司 | A kind of adaptive absorption system and Switching Power Supply for Switching Power Supply |
| CN110266181A (en) * | 2018-03-12 | 2019-09-20 | 中兴通讯股份有限公司 | A kind of clamp circuit and clamp methods |
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Application publication date: 20120822 |