CN2837883Y - Light source drive circuit - Google Patents
Light source drive circuit Download PDFInfo
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- CN2837883Y CN2837883Y CN 200520132847 CN200520132847U CN2837883Y CN 2837883 Y CN2837883 Y CN 2837883Y CN 200520132847 CN200520132847 CN 200520132847 CN 200520132847 U CN200520132847 U CN 200520132847U CN 2837883 Y CN2837883 Y CN 2837883Y
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- light source
- transformer
- ripple
- square wave
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Abstract
The utility model provides a light source driving circuit which comprises a wave width controlling circuit, a first transformer, a resonant circuit and a second transformer, wherein the wave width controlling circuit utilizes an alternating current power supply to generate a square wave; the primary side of the first transformer inputs the square wave, and the secondary side of the first transformer outputs a variable voltage square wave; the resonant circuit inputs the variable voltage square wave to generate a resonant sine wave; the primary side of the second transformer inputs the resonant sine wave, and the secondary side of the second transformer outputs a variable voltage sine wave so as to drive a light source. Thereby, the utility model has high energy converting efficiency and solves the problem of high cost due to the limitation of safety regulations.
Description
Technical field
The utility model relates to a kind of light source driving circuit, and particularly a kind of have high-energy conversion efficiency and avoid producing expensive light source driving circuit because of the restriction of security legislation.
Background technology
As shown in Figure 1, be the synoptic diagram of conventional lighting sources driving circuit, it can be applicable to LCD (LCD) module backlight.Earlier mains ac power supply 1 (exchanging 50/60 hertz) converted to the direct current output DCOP of low-voltage through AC-DC converter 2, usually between 12 volts to 36 volts, again by direct current output DCOP, through direct current input transverter 3 (DC INPUT Inverter) energy conversion is become high-frequency ac power, usually have 500 volts to 1500 volts the voltage and the frequency of 30 to 100 KHz, comprise light supply apparatus 4 as cold-cathode fluorescence lamp (Cold Cathode Fluorescent Lamp) with driving.
Fig. 2 is the synoptic diagram of switching power supply device (Switch Power Supply), be an instantiation of above-mentioned existing AC-DC converter, comprising: the wide control circuit 8 of rectification circuit, ripple that includes rectifier filer 6 and electric capacity 7 of input mains ac power supply 5 (exchanging 50/60 hertz), transformer T1, secondary commutation filtering circuit 9 and feedback control circuit 10.This switch power supply apparatus converts civil power to existing direct current input transverter required direct current.
Fig. 3 is an instantiation of above-mentioned existing direct current input transverter, comprising: the wide control circuit 11 of the ripple of input DC power DCIP, resonant circuit 12, transformer T2 and feedback control circuit 13.The function of resonant circuit 12 is boosted or is boosted without transformer through transformer T2 as required then for producing an AC power (alternating voltage or alternating current), comprises light supply apparatus 14 as cold-cathode fluorescence lamp with driving.The wide control circuit 11 of ripple provides an energy to make resonant circuit 12 produce alternating voltage or alternating current, this energy can be voltage or current forms, and can be by the signal feedback of feedback control circuit 13, the energy that the wide control circuit 11 of control wave provides, and then the AC power that resonant circuit 12 is produced is controlled and realize the purpose of light modulation.
Above-mentioned conventional lighting sources driving circuit has following defective:
1. gross energy conversion efficiency (Total Efficiency) is low.Because the conventional lighting sources driving circuit is made up of an AC-DC converter and a transverter (Inverter), according to present handy technology, the efficient of AC-DC converter is about about 85% (0.85), the efficient of transverter is about 85% (0.85), therefore, the efficient of conventional lighting sources driving circuit is about 0.85 * 0.85=0.7225 (72.25%).
2. continue the existing direct current input transverter with reference to figure 3, its voltage of importing usually is between 5 volts to 30 volts.If before direct supply DCIP, add a current rectifying and wave filtering circuit (not shown) again, then also can realize in theory and the identical effect of existing direct current input transverter, and efficient is higher than aforesaid available circuit.Yet, according to security legislation (safety) in fact to the requirement of transverter, primary side and the safe spacing between primary side of transformer T2 must be at least the 16-18 millimeter, and must be able to bear the Hi-pot test (Hi-POT Test) of 25 kilovolts, be difficult to realize above-mentioned direct current input transverter so technically, and improved cost.
The utility model content
According to the defective of above-mentioned prior art, the utility model provides a kind of to have high-energy conversion efficiency and avoids producing expensive light source driving circuit because of the restriction of security legislation.
Fundamental purpose of the present utility model is to overcome above-mentioned defective, and for avoiding the existence of this defective, the utility model provides a kind of light source driving circuit, and it comprises: the wide control circuit of a ripple, utilize an AC power to produce a square wave; One first transformer, its primary side is imported this square wave, and its primary side is exported a transformation square wave; One resonant circuit is imported this transformation square wave, to produce a humorous vibratory string ripple; And one second transformer, its this humorous vibratory string ripple of primary side input, and its primary side exports a transformation string ripple, to drive this light source.
Thus, of the present utility model have a following advantage, that is, have high-energy conversion efficiency and avoid producing expensive problem because of the restriction of security legislation.
Description of drawings
Fig. 1 is the synoptic diagram of conventional lighting sources driving circuit;
Fig. 2 is existing switching power supply schematic representation of apparatus;
Fig. 3 is the synoptic diagram of existing direct current input transverter;
Fig. 4 is the synoptic diagram according to the specific embodiment of light source driving circuit of the present utility model;
Fig. 5 is the synoptic diagram according to first preferred embodiment of light source driving circuit of the present utility model;
Fig. 6 A is the synoptic diagram according to second preferred embodiment of light source driving circuit of the present utility model;
Fig. 6 B is the action waveforms synoptic diagram according to second preferred embodiment of the present utility model; And
Fig. 7 is the synoptic diagram according to the 3rd preferred embodiment of light source driving circuit of the present utility model.
Symbol description
1 mains ac power supply, 2 AC-DC converter
3 direct currents input transverter, 4 light supply apparatuses
5 mains ac power supply, 6 rectifier filers
The wide control circuit of 7 electric capacity, 8 ripples
9 secondary commutation filtering circuits, 10 feedback control circuits
13 feedback control circuits, 14 light supply apparatuses
The wide control circuit of 15 light source driving circuit 16 ripples of the present utility model
17 resonant circuits, 18 light supply apparatuses
19 feedback control circuits, 20 Wave-wide regulation controlled electric devices
21,22 cold-cathode fluorescence lamp C0 electric capacity
C1 resonant capacitance C2, C3 electric capacity
C4, C5 all shake capacitor C 6, C7 resonant capacitance
CC commutation capacitor D1, D2 commutation diode
D11 internal body diodes D21 internal body diodes
The output of DCIP direct supply DCOP direct current
I
LThrough the electric current L of resonant inductance L resonant inductance
L1, L2 resonant inductance Q1, Q2 current switch
Q3, Q4 rectifying transistor Q1V
GSSwitching signal
Q2V
GSSwitching signal R1, R2 divider resistance
T1 transformer T2 transformer
The T3 first transformer T4 second transformer
Arbitrary time point between t1a time t1 to t2
Arbitrary time point between t3a time t3 to t4
Toff closing time
The square wave V2 transformation square wave that the wide control circuit of V1 ripple produces
Embodiment
As shown in Figure 4, be synoptic diagram according to the specific embodiment of light source driving circuit 15 of the present utility model.Wherein, light source driving circuit 15 of the present utility model comprises: the wide control circuit 16 of ripple, and it utilizes an AC power to produce a square wave, and this AC power can be the civil power through the current rectifying and wave filtering circuit that comprises rectifier filer and commutation capacitor CC; The first transformer T3, its primary side is imported this square wave, and its primary side is exported a transformation square wave V2; Resonant circuit 17 is imported this transformation square wave V2, to produce a humorous vibratory string ripple; The second transformer T4, this humorous vibratory string ripple of its primary side input, and its primary side exports a transformation string ripple, and with driving light source device 18, wherein, light supply apparatus 18 can be the light source of LCD backlight module; And feedback control circuit 19, utilize this transformation string ripple to produce a feedback signal that feeds back to the wide control circuit 16 of this ripple.
Compare with the conventional lighting sources drive unit, especially, above-mentioned light source driving circuit of the present utility model is simplified merging with aforementioned two groups of wide control circuits of ripple of the prior art and two groups of feedback control circuits (using respectively at switching power supply device and direct current input transverter), only use one group of wide control circuit of ripple and one group of feedback control circuit, simplify or cancel the secondary commutation filtering circuit in the switching power supply device simultaneously, wherein, the high pressure of the first transformer T3 after with general commercial power rectification converts low pressure (definition low pressure is 42 volts of direct currents or exchanges 30 volts in the safety) to, square wave with this low pressure directly converts string wave voltage or electric current to through resonant circuit again, and back output comprises light supply apparatus 18 as cold-cathode fluorescence lamp with driving after the second transformer T4 boosts.Therefore, than the conventional lighting sources driving circuit, light source drive device of the present utility model can reach higher efficient, has reduced manufacturing cost, and can avoid aforesaid safety problem.
Fig. 5 is the synoptic diagram of first preferred embodiment of above-mentioned light source driving circuit of the present utility model, wherein, with parallel way this resonant circuit is set.As shown in Figure 5, and with reference to figure 4, a kind of light source driving circuit of the present utility model comprises: the wide control circuit 16 of ripple, input is through comprising the civil power of current rectifying and wave filtering circuit of rectifier filer and commutation capacitor CC, and the wide control circuit of this ripple comprises Wave-wide regulation controlled electric device 20 (pulse width modulator), two current switch Q1 and Q2 and capacitor C 0; The first transformer T3, the square wave that its primary side input is produced by the wide control circuit 16 of ripple, and its primary side output transformation square wave V2 are to meet the regulation of safety to low pressure; Resonant circuit 17 is imported this transformation square wave V2 through commutation diode D1, D2, and comprises resonant inductance L1 and L2, resonant capacitance C1 and pass through rectifying transistor Q3 and the Q4 that divider resistance R1 and R2 produce signal controlling respectively, to produce a humorous vibratory string ripple; The second transformer T4, its this humorous vibratory string ripple of primary side input, and its primary side is exported a transformation string ripple, with driving light source device 18, wherein, light supply apparatus 18 is for can be used for the light source of LCD backlight module, and comprises the cold-cathode fluorescence lamp 21,22 of connecting with capacitor C 2, C3 respectively; And a feedback control circuit 19, utilize this transformation string ripple to produce a feedback signal that feeds back to the wide control circuit 16 of this ripple.
Fig. 6 A is the synoptic diagram of second preferred embodiment of above-mentioned light source driving circuit of the present utility model, wherein, with simple parallel way this resonant circuit is set.As shown in Figure 6A, and with reference to figure 4, a kind of light source driving circuit of the present utility model comprises: the wide control circuit 16 of ripple, input is through comprising the civil power of current rectifying and wave filtering circuit of rectifier filer and commutation capacitor CC, and the wide control circuit of this ripple comprises Wave-wide regulation controlled electric device 20, two current switch Q1 and Q2, capacitor C 0; The first transformer T3, the square wave V1 that its primary side input is produced by the wide control circuit 16 of ripple, and its primary side output transformation square wave V2 are to meet the regulation of safety to low pressure; Resonant circuit 17, and have resonant inductance L, resonant capacitance C4, C5, to produce a humorous vibratory string ripple; The second transformer T4, its this humorous vibratory string ripple of primary side input, and its primary side is exported a transformation string ripple, with driving light source device 18, wherein, light supply apparatus 18 is for can be used for the light source of LCD backlight module, and comprises the cold-cathode fluorescence lamp 21,22 of connecting with capacitor C 2, C3 respectively; And a feedback control circuit 19, utilize this transformation string ripple to produce a feedback signal that feeds back to the wide control circuit 16 of this ripple.
Below, be example with second preferred embodiment shown in Fig. 6 A, the manner of execution of light source driving circuit of the present utility model is described.
Fig. 6 B is the synoptic diagram of the action waveforms of above-mentioned second preferred embodiment.Shown in Fig. 6 B, and with reference to figure 6A, the civil power of the current rectifying and wave filtering circuit of input through comprising rectifier filer and commutation capacitor CC, the switch motion that the wide control circuit 16 of ripple replaces by current switch Q1, Q2, export a square wave V1 primary side of the first transformer T3 to, produce the lower transformation square wave V2 of voltage through the first transformer T3, to meet safety low-voltage standard, produce alternating current through resonant circuit 17 again and boost, with driving light source device 18 through the second transformer T4.
Continue with reference to figure 6B and 6A, to t1, control the switching signal Q2V of current switch Q2 between its grid (gate) and source electrode (source) through the wide control circuit 16 of ripple at time t0
GSBe noble potential, make current switch Q2 conducting, input current through the drain electrode (drain) of the first transformer T3, capacitor C 0, current switch Q2 to source electrode, so that earth terminal.At this moment, respond to a voltage V1 (not shown) in the first transformer T3 primary side, after the first transformer T3 transformation, respond to identical but the voltage V2 that its noble potential is lower than voltage V1 of a polarity in primary side, voltage V2 is put on resonant circuit 17, produce the string ripple through resonant inductance L and resonant capacitance C5 resonance, its frequency is 1/2 π * (capacitance of the inductance value of resonant inductance L * resonant capacitance C5)
1/2, wherein the time between t0 to t1 must be less than or equal to the semiperiod of this string ripple.In the closing time of time t1 to t2 toff,, make the switching signal Q2V of current switch Q2 between its grid and source electrode through wide control circuit 16 controls of ripple
GSTherefore be electronegative potential, make not conducting of current switch Q2, blocked originally draining through the first transformer T3, capacitor C 0, current switch Q2 to the electric current of source electrode.At this moment, resonant inductance L produces a back electromotive force.Want to make the primary current direction to remain unchanged, and make the voltage V2 reversal of poles of responding in the first transformer T3 primary side, also make the polarity of voltage counter-rotating of first transformer T3 primary side induction, electric current is then by the first transformer T3 primary side, through the flow through diode D11 of current switch Q1 inside of capacitor C 0, return the first transformer T3 primary side, the arbitrary time point t1a of while between time t1 to t2, by wide control circuit 16 controls of ripple, the grid of current switch Q1 and the switching signal Q1V between source electrode will be outputed to
GSBe converted to noble potential, make current switch Q1 conducting.In time t2 to t3, this moment resonant inductance L electric current I
LBecause of concerning phase place, resonance enters negative half period, current switch Q1 this moment conducting, so current polarity counter-rotating.By the first transformer T3 primary side the draining of current switch Q1 of flowing through to source electrode, get back to the first transformer T3 primary side through capacitor C 4 again, its action is similar to time t0 to t1.In the closing time of time t3 to t4 toff,, output to the grid of current switch Q1 and the switching signal Q1V between source electrode by wide control circuit 16 controls of ripple
GSBe electronegative potential, make not conducting of current switch Q1, therefore blocking the draining of the first transformer T3 primary side, current switch Q1 of originally flowing through arrives the electric current of electric C4 again to source electrode.At this moment, resonant inductance L produces a back electromotive force, want to make the primary current direction to remain unchanged, and make the voltage V2 reversal of poles of responding in the first transformer T3 primary side, also make the voltage V1 reversal of poles of first transformer T3 primary side induction, electric current then by the first transformer T3 primary side through capacitor C 3 just (+) hold to earth terminal, get back to the first transformer T3 primary side through current switch Q2 internal body diodes D21 and capacitor C 4 again.Arbitrary time point t3a between time t3 to t4 by wide control circuit 16 controls of ripple, makes the grid of current switch Q2 and the switching signal Q2V between source electrode simultaneously
GSBe converted to noble potential, make current switch Q2 conducting, so go round and begin again, form resonance, and boost with driving light source device 18 through the second transformer T4.
In the above-mentioned light source driving circuit of the present utility model, preferably, also comprise feedback control circuit 19, feed back to the feedback signal of the wide control circuit 16 of ripple with generation, make the wide control circuit 16 of ripple suitably control the operating frequency of light source driving circuit, output to the variation of the electric current of light supply apparatus 18 with control, and then realize the brightness that meets demand that control light supply apparatus 18 produces, and above-mentioned light modulation action can be continuous mode or BURST pattern.
Fig. 7 is the synoptic diagram of the 3rd preferred embodiment of light source driving circuit of the present utility model.Wherein, this resonant circuit is with the series system setting.As shown in Figure 7, and with reference to figure 4, a kind of light source driving circuit of the present utility model can comprise: the wide control circuit 16 of ripple, the civil power of the current rectifying and wave filtering circuit of input through comprising rectifier filer and commutation capacitor CC, and the wide control circuit of this ripple comprises Wave-wide regulation controlled electric device 20, two current switch Q1 and Q2, capacitor C 0; The first transformer T3, the square wave V1 that its primary side input is produced by the wide control circuit 16 of ripple, and its primary side output transformation square wave V2 are to meet the regulation of safety to low pressure; Resonant circuit 17 utilizes the stray inductance (not shown) of resonant capacitance C6, C7 and the second transformer T4 to produce humorous vibratory string ripple; The second transformer T4, this humorous vibratory string ripple of its primary side input, and its primary side exports a transformation string ripple, with driving light source device 18.Wherein, light supply apparatus 18 is for can be used for the light source of LCD backlight module, and comprises the cold-cathode fluorescence lamp 21,22 of connecting with capacitor C 2, C3 respectively; And a feedback control circuit 19, utilize this transformation string ripple to produce a feedback signal that feeds back to the wide control circuit 16 of this ripple.
As mentioned above, the utility model meets patent three important documents fully: the usability on novelty, progressive and the industry.
The above is a preferred embodiment of the present utility model only, is not limited to the utility model, and for a person skilled in the art, the utility model can have various changes and variation.All within spirit of the present utility model and principle, any modification of being done, be equal to replacement, improvement etc., all should be included within the protection domain of the present utility model.
Claims (7)
1. light source driving circuit is characterized in that comprising:
The wide control circuit of one ripple utilizes an AC power to produce a square wave;
One first transformer, its primary side is imported described square wave, and its primary side is exported a transformation square wave;
One resonant circuit is imported described transformation square wave, to produce a humorous vibratory string ripple; And
One second transformer, its primary side are imported described humorous vibratory string ripple, and its primary side exports a transformation string ripple, to drive described light source.
2. light source driving circuit according to claim 1, wherein, described AC power utilizes civil power to produce through a rectifier filer.
3. light source driving circuit according to claim 1, wherein, the wide control circuit of described ripple can have semibridge system, full-bridge type, push-pull type or monocrystal etc. and open up the servant, with two current switches of Wave-wide regulation controlled electric device control, to produce described square wave.
4. light source driving circuit according to claim 1, wherein, described transformation square wave has the low pressure that meets the safety definition.
5. light source driving circuit according to claim 1, wherein, described resonant circuit be antiresonant circuit, series resonant circuit or E type (Class E) but etc. the resonant circuit of driving light source.
6. light source driving circuit according to claim 1, wherein, described light source comprises at least one cold-cathode fluorescence lamp.
7. according to each described light source driving circuit in the claim 1 to 6, it is characterized in that also comprising a feedback control circuit, utilize described transformation string ripple to produce a feedback signal that feeds back to the wide control circuit of described ripple.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200520132847 CN2837883Y (en) | 2005-11-14 | 2005-11-14 | Light source drive circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200520132847 CN2837883Y (en) | 2005-11-14 | 2005-11-14 | Light source drive circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN2837883Y true CN2837883Y (en) | 2006-11-15 |
Family
ID=37392371
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200520132847 Expired - Fee Related CN2837883Y (en) | 2005-11-14 | 2005-11-14 | Light source drive circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN2837883Y (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101060740B (en) * | 2006-04-21 | 2011-03-23 | 鸿富锦精密工业（深圳）有限公司 | Discharge lamp drive device |
| CN101363998B (en) * | 2007-08-07 | 2012-07-18 | 奇美电子股份有限公司 | Backlight module and light modulation method thereof |
-
2005
- 2005-11-14 CN CN 200520132847 patent/CN2837883Y/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101060740B (en) * | 2006-04-21 | 2011-03-23 | 鸿富锦精密工业（深圳）有限公司 | Discharge lamp drive device |
| CN101363998B (en) * | 2007-08-07 | 2012-07-18 | 奇美电子股份有限公司 | Backlight module and light modulation method thereof |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |