CN101351072B - Control circuit for light source - Google Patents
Control circuit for light source Download PDFInfo
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- CN101351072B CN101351072B CN2007100760917A CN200710076091A CN101351072B CN 101351072 B CN101351072 B CN 101351072B CN 2007100760917 A CN2007100760917 A CN 2007100760917A CN 200710076091 A CN200710076091 A CN 200710076091A CN 101351072 B CN101351072 B CN 101351072B
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Abstract
The invention provides a light source control circuit which comprises a controller, a plurality of light sources and a plurality of current balance circuits; wherein, each light source is correspondingly connected with a current balance circuit; a plurality of current balance circuits sample the illuminating intensity signals of a plurality of light sources and obtain a feedback signal and output the feedback signal to the controller after making balanced adjustment of the sample results; the controller adjusts the illumination of the light source according to the feedback signal.
Description
Technical field
The present invention relates to a kind of control circuit for light source.
Background technology
Liquid crystal indicator is owing to it has in light weight, little power consumption, radiation is low and advantage such as easy to carry is widely used in modernized information equipment, like display, TV, mobile phone and digital product etc.But because liquid crystal molecule self can not be luminous, thereby common liquid crystal indicator need provide the demonstration of area source realization image by a module backlight, and this module backlight is to control its inner light source through a control circuit for light source to carry out work.
Seeing also Fig. 1, is a kind of circuit diagram of prior art control circuit for light source.This control circuit for light source 100 comprises one first feedback circuit 110, one second feedback circuit 120, one the 3rd feedback circuit 130, one the 4th feedback circuit 140 and a controller 150.
This controller 150 comprise one be used for the received current feedback signal induction by current end 151 and be used to receive the luminance input 152 of luminance signal.
This first feedback circuit 110 comprises one first fluorescent tube, 111, one first diodes 112 and one second diode 113.Wherein the high-pressure side 118 of this first fluorescent tube 111 is used to receive high-frequency ac voltage, and its low-pressure end 119 is connected respectively to the positive pole of this first diode 112 and the negative pole of this second diode 113.The plus earth of this second diode 113, the negative pole of this first diode 112 are connected to the induction by current end 151 of this controller 150.
This second feedback circuit 120, the 3rd feedback circuit 130 and the 4th feedback circuit 140 comprise one second fluorescent tube 121, one the 3rd fluorescent tube 131 and one the 4th fluorescent tube 141 respectively.And the circuit structure of this second feedback circuit 120, the 3rd feedback circuit 130 and the 4th feedback circuit 140 is identical with this first feedback circuit 110.The high-pressure side 118 of this first fluorescent tube 111 interconnects through a coupling capacitance 170 with the high-pressure side of this second fluorescent tube 121 (not indicating).The high-pressure side of the 3rd fluorescent tube 131 (not indicating) interconnects through another coupling capacitance 180 with the high-pressure side (not indicating) of the 4th fluorescent tube 141.
When these control circuit for light source 100 work; The high-pressure side of this first feedback circuit 110, this second feedback circuit 120, the 3rd feedback circuit 130 and the 4th feedback circuit 140 receives the high-frequency ac voltage signal respectively, and this first fluorescent tube 111, this second fluorescent tube 121, the 3rd fluorescent tube 131 and the 4th fluorescent tube 141 carry out luminous under the driving of this high-frequency ac voltage signal.With this first feedback circuit 110 is example; It produces a drive current under the effect of this high-frequency ac voltage; And at the negative half-cycle of this high-frequency ac voltage; This drive current is held through this second diode 113 by the low-pressure end 119 output backs of first fluorescent tube 111 with flowing to; And at the positive half period of this high-frequency ac voltage, this drive current produces a feedback current and flows to the induction by current end 151 of controller 150 through this first diode 112 after low-pressure end 119 outputs of this first fluorescent tube 111.In like manner, this moment this second fluorescent tube 121, the 3rd fluorescent tube 131 and the 4th fluorescent tube 141 the also corresponding respectively induction by current end 151 that produces feedback current and flow to controller 150 of drive current.
After the feedback current that this controller 150 receives from this first feedback circuit 110, this second feedback circuit 120, the 3rd feedback circuit 130 and the 4th feedback circuit 140; The luminance signal that this feedback current of comparative analysis and its luminance input 152 are received; And export a control signal according to the comparative analysis result and control the high-frequency ac voltage that this control circuit for light source 100 is loaded into this first fluorescent tube 111, this second fluorescent tube 121, the 3rd fluorescent tube 131 and the 4th fluorescent tube 141, thereby realize the luminosity of this fluorescent tube 111,112,113 and 114 is regulated.
But; Because the feedback current of this first fluorescent tube 111, this second fluorescent tube 121, the 3rd fluorescent tube 131 and 141 outputs of the 4th fluorescent tube all outputs to this controller 150 through this induction by current end 151 simultaneously, promptly 150 pairs of these fluorescent tubes 111,112,113 of this controller and 114 current sample are independently.Therefore; When the feedback current of the output of a fluorescent tube wherein is big; This bigger feedback current can cover other three less feedback current; This moment, this controller 150 was just regulated the driving voltage of this fluorescent tube 111,112,113 and 114 according to this bigger feedback current; And fail according to the comprehensive condition of this fluorescent tube 111,112,113 and 114 feedback currents its driving voltage to be carried out comprehensive adjustment, cause the adjusting of luminosity of 150 pairs of these fluorescent tubes 111,112,113 of this controller in this control circuit for light source 100 and 114 uneven thus, and then shorten the useful life of this fluorescent tube 111,112,113 and 114.
Summary of the invention
Be to solve the fluorescent tube short problem in useful life of prior art control circuit for light source, be necessary to provide a kind of driving voltage of each fluorescent tube of comprehensive adjustment, prolong each fluorescent tube control circuit for light source in useful life.
A kind of control circuit for light source; It comprises a controller, a plurality of light source and a plurality of current balance circuit; Each light source correspondence is connected to a current balance circuit; These a plurality of current balance circuits are sampled to the luminosity signal of these a plurality of light sources, and sampled result is carried out obtaining a feedback signal after the balance adjustment output to this controller, and this controller is regulated the luminous of this light source according to this feedback signal; Each current balance circuit comprises a biasing circuit and a positive-negative-positive bipolar transistor, and this transistorized base stage is connected to this biasing circuit; These a plurality of current balance circuits connect successively; Transistor in the current balance circuit of head end; Its collector electrode is connected with the induction by current end of this controller; Its emitter is connected with transistorized collector electrode in the next stage current balance circuit; Transistor in the terminal current balance circuit, its collector electrode is connected its grounded emitter with transistorized emitter in the upper level current balance circuit; Be in the transistor in the current balance circuit between head end and the end, its collector electrode is connected with transistorized emitter in the upper level current balance circuit, and its emitter is connected with transistorized collector electrode in the next stage current balance circuit.
A kind of control circuit for light source; It comprises a controller, a plurality of light source and a plurality of current balance circuits that are connected successively; The corresponding current balance circuit of each light source; These a plurality of current balance circuits are sampled to the luminosity signal of these a plurality of light sources, and sampled result is carried out obtaining a feedback signal after the balance adjustment output to this controller, and this controller is regulated the luminous of this light source according to this feedback signal; Each current balance circuit comprises a biasing circuit and a npn type bipolar transistor, and this transistorized base stage is connected to this biasing circuit; Transistor in the current balance circuit of head end; Its emitter is connected with the induction by current end of this controller; Its collector electrode is connected with transistorized emitter in the next stage current balance circuit; Transistor in the terminal current balance circuit, its emitter is connected its grounded collector with transistorized collector electrode in the upper level current balance circuit; Be in the transistor in the current balance circuit between head end and the end, its emitter is connected with transistorized collector electrode in the upper level current balance circuit, and its collector electrode is connected with transistorized emitter in the next stage current balance circuit.
Compared to prior art; Control circuit for light source of the present invention carries out balance adjustment through a plurality of current balance circuits of connecting successively to the luminosity signal of each light source, this controller and then the luminous of each light source adjusted according to resulting feedback signal after this balance adjustment.Because this current balance circuit is taked balance adjustment to the luminosity signal of each light source; Thereby this control circuit for light source can be regulated the driving voltage of this light source according to the comprehensive luminous situation of all light sources; It can take into account the brightness that is adjusted to all light sources, thus avoid since wherein the luminance signal of a certain light source greatly cover other luminance signal and then make the adjusting work inaccuracy of this controller.Therefore, the brightness of all light sources is regulated in control circuit for light source overall balance of the present invention, makes whole lamp system luminous more equably, thereby prolongs the useful life of each fluorescent tube.
Description of drawings
Fig. 1 is a kind of circuit diagram of prior art control circuit for light source.
Fig. 2 is the circuit diagram of control circuit for light source first execution mode of the present invention.
Fig. 3 is the circuit diagram of control circuit for light source second execution mode of the present invention.
Embodiment
Seeing also Fig. 2, is the circuit diagram of control circuit for light source first execution mode of the present invention.This control circuit for light source 200 comprises one first feedback circuit 210, one second feedback circuit 220, one the 3rd feedback circuit 230, one the 4th feedback circuit 240, a controller 250 and an open loop protection circuit 260.
This controller 250 is a pulse width modulation integrated circuit (Pulse Width Modulation Integrated Circuit; PWM IC), it comprise one be used for the received current feedback signal induction by current end 251, the luminance input 252 and that is used to receive luminance signal be used to receive the open-circuit-protection control end 253 of fluorescent tube open-circuit-protection control signal.
This open loop protection circuit 260 comprises a first input end 261, one second input 262, one the 3rd input 263, a four-input terminal 264 and an output 265.Wherein, this output 265 is connected to the open-circuit-protection control end 253 of this controller 250.This first input end 261, this second input 262, the 3rd input 263 and this four-input terminal 264 are connected respectively to this first feedback circuit 210, this second feedback circuit 220, the 3rd feedback circuit 230 and the 4th feedback circuit 240; It is respectively applied for samples to each feedback circuit, thereby realizes the operating state of each feedback circuit is detected.
This first feedback circuit 210 comprises one first fluorescent tube 211, one first diode 212, a sampling resistor 216, a divider resistance 217 and one first current balance circuit (indicating).This first current balance circuit comprises one first biasing resistor 213, a first transistor 214 and one second biasing resistor 215.Wherein this first fluorescent tube 211 can be a cold cathode ray tube.This first transistor 214 is bipolar npn transistor npn npns, and it comprises a base stage (not indicating), an emitter (not indicating) and a collector electrode (not indicating).
This first fluorescent tube 211 comprises a high-pressure side 218 and a low-pressure end 219.This high-pressure side 218 is used to receive high-frequency ac voltage, and this low-pressure end 219 is connected to the positive pole of this first diode 212 simultaneously through these divider resistance 217 ground connection.The negative pole of this first diode 212 is connected to the first input end 261 of this open loop protection circuit 260 on the other hand on the one hand through first biasing resistor 213 and second biasing resistor, 215 ground connection of series connection each other, simultaneously through these sampling resistor 216 ground connection.The base stage of this first transistor 214 is connected between this first biasing resistor 213 and second biasing resistor 215, and its collector electrode is connected to the induction by current end 251 of this controller 250, and its emitter is connected to this second feedback circuit 220.In this first feedback circuit 210, this divider resistance 217 is used for this high-frequency ac voltage is carried out dividing potential drop, and makes first feedback circuit 210 form an ac circuit.This first diode 212 is used to carry out halfwave rectifier, makes this open loop protection circuit 260 and this controller 250 all remain on the positive half period of this high-frequency ac voltage respectively to the sampling that voltage and current carried out of this first feedback circuit 210.This first biasing resistor 213 and second biasing resistor 215 constitute a biasing circuit for this first transistor 214 provides a working point accurately, make it be operated in the saturation region.
This second feedback circuit 220 comprises one second fluorescent tube 221, one second diode 222 and one second current balance circuit (indicating); The 3rd feedback circuit 230 comprises one the 3rd fluorescent tube 231, one the 3rd diode 232 and one the 3rd current balance circuit (indicating), and the 4th feedback circuit 240 comprises one the 4th fluorescent tube 241, one the 4th diode 242 and one the 4th current balance circuit (indicating).Wherein, this second current balance circuit, the 3rd current balance circuit and the 4th current balance circuit comprise respectively and a transistor seconds 224, one the 3rd transistor 234 and one the 4th transistor 234.The internal structure of this second feedback circuit 220, the 3rd feedback circuit 230 and the 4th feedback circuit 240 is identical with this first feedback circuit 210.The negative pole of this second diode 222, the 3rd diode 232 and the 4th diode 242 is connected respectively to second input 262, the 3rd input 263 and the four-input terminal 264 of this open loop protection circuit 260.The collector electrode of this transistor seconds 224 is connected to the emitter of this first transistor 214, and its emitter is connected to the collector electrode of the 3rd transistor 234.The emitter of the 3rd transistor 234 is connected to the collector electrode of the 4th transistor 244, the grounded emitter of the 4th transistor 244.And the high-pressure side 218 of this first fluorescent tube 211 interconnects through a coupling capacitance 270 with the high-pressure side of this second fluorescent tube 221 (not indicating).The high-pressure side of the 3rd fluorescent tube 231 (not indicating) interconnects through another coupling capacitance 280 with the high-pressure side (not indicating) of the 4th fluorescent tube 241.
When these control circuit for light source 200 work; The high-pressure side of this first fluorescent tube 211, this second fluorescent tube 221, the 3rd fluorescent tube 231 and the 4th fluorescent tube 241 receives the high-frequency ac voltage signal respectively, and this first fluorescent tube 211, this second fluorescent tube 221, the 3rd fluorescent tube 231 and the 4th fluorescent tube 241 are luminous under the driving of this high-frequency ac voltage signal.
In this first feedback circuit 210, the high-pressure side of this first fluorescent tube 211 receives after this high-frequency ac voltage signal, produces an AC driving electric current I.This AC driving electric current I is held through this divider resistance 217 with flowing to, forms an ac circuit thus.And; Negative half-cycle at this high-frequency ac voltage; This first diode 212 is owing to reverse bias is in cut-off state; Only exist the branch road that by this divider resistance 217 formed in this first feedback circuit 210 this moment, so this AC driving electric current I is just all held through this divider resistance 217 with flowing to.And at the positive half period of this high-frequency ac voltage, this first diode 212 is in conducting state owing to forward bias, and this moment, this AC driving electric current I just was divided into one first branch current I after low-pressure end 219 outputs of this first fluorescent tube 211
1With one second branch current I
2, and this first branch current I
1Hold this second branch current I through this divider resistance 217 with flowing to
2Flow to this first diode 212.
This second branch current I
2After the negative pole output by this first diode 212; Hold through this sampling resistor 216 on the one hand with flowing to; Cause these sampling resistor 216 two ends to produce a pressure drop thus; This moment, this open loop protection circuit 260 was the pressure drop at these sampling resistor 216 two ends through the resulting sampled result of 261 pairs of these first feedback circuits of its first input end, 210 samplings, and promptly this moment, this first input end 261 was in high level.On the other hand, this second branch current I
2Flow to this first biasing resistor 213, because this first transistor 214 is generally operational in the saturation region, therefore at this second branch current I
2Effect under, this first transistor 214 produces a base current I
B1, and then produce a collector current I
C1With an emitter current I
E1, and this collector current I
C1Satisfy I
C1=β I
B1, wherein β is the current amplification factor of this first transistor 214, it is by the internal structure of this first transistor 214, such as impurity concentration, base width etc. decision.This emitter current I
E1Size approximate this collector current I
C1This collector current I
C1And then, output to the induction by current end 251 of this controller 250 as a feedback current.
In like manner; Positive half period at this high-frequency ac voltage; This open loop protection circuit 260 is sampled to this second feedback circuit 220, the 3rd feedback circuit 230 and the 4th feedback circuit 240 respectively through its second input 262, the 3rd input 263 and four-input terminal 264, and sampled result is high level.Thereby this open loop protection circuit 260 is just exported one first control signal through its output 265 to this controller 250 at this moment; This first control signal is a low level; After this controller 250 receives this low level, just control this control circuit for light source 200 operate as normal.
Simultaneously, the 3rd transistor 234 of transistor seconds 224, the three feedback circuits 230 of this second feedback circuit 220 and the 4th transistor 244 of the 4th feedback circuit 240 also produce base current I respectively
B2, I
B3, I
B4, and then produce collector current I respectively
C2, I
C3, I
C4With emitter current I
E2, I
E3, I
E4And this emitter current I
E2, I
E3, I
E4Size respectively with this collector current I
C2, I
C3, I
C4Equate.Because the emitter of this first transistor 214 is connected with the collector electrode of this transistor seconds 224; The emitter of this transistor seconds 224 is connected with the collector electrode of the 3rd transistor 234; The emitter of the 3rd transistor 234 is connected with the collector electrode of the 4th transistor 244, so the collector current I of each transistor 214,224,234 and 244
C1, I
C2, I
C3, I
C4Satisfy I
C1=I
C2=I
C3=I
C4That is to say; Each feedback circuit 210,220,230 and 240 is through this transistor 214,224,234 and 244 this feedback current of balance adjustment in the saturation region, and the feedback current that obtains after the balance adjustment the most at last outputs to the induction by current end 251 of this controller 250 through the collector electrode of this first transistor 214.Therefore; When the inner a certain lamp current of this control circuit for light source 200 is big; Because the current balance type regulating action of this transistor 214,224,234 and 244; This big electric current can't cover other lamp tube current, so the feedback current that received of this controller 250 can reflect the comprehensive luminous situation of all fluorescent tubes 211,221,231 and 241 more accurately.
This controller 250 receives this through after feedback current of balance adjustment, and the luminance signal that this feedback current and its luminance input 252 are received compares analysis, and exports a pulse duration control signal according to the comparative analysis result.This this control circuit for light source 200 of pulse duration control signal control is loaded into the high-frequency ac voltage of this first fluorescent tube 211, this second fluorescent tube 221, the 3rd fluorescent tube 231 and the 4th fluorescent tube 241, thereby realizes the luminosity of each fluorescent tube is regulated.
When in this control circuit for light source 200 during arbitrary fluorescent tube generation open circuit situation; With these first fluorescent tube, 211 open circuits is example; The drive current of this first fluorescent tube 211 of flowing through this moment disappears; There is not pressure drop in these sampling resistor 216 two ends, and this open loop protection circuit 260 is a low level through the result that these first input end 261 samplings obtain.When these open loop protection circuit 260 these first input ends 261 of detection are low level, just arrive this controller 250, and this second control signal is a high level through its output 265 outputs one second control signal.After this controller 250 receives this high level, control this control circuit for light source 200 rapidly and get into guard mode.
Compared to prior art; Control circuit for light source 200 of the present invention is provided with the current balance circuit that comprises this first transistor 214, this transistor seconds 224, the 3rd transistor 234 and the 4th transistor 244 respectively at this first feedback circuit 210, this second feedback circuit 220, the 3rd feedback circuit 230 and the 4th feedback circuit 240; And through this transistor 214,224,234 and 244 each feedback current of balance adjustment, this controller 250 and then luminosity of this fluorescent tube 211,221,231 and 241 is regulated according to the feedback current that obtains after this even regulation of balance.Therefore; Control circuit for light source 200 of the present invention is to regulate according to the comprehensive luminosity of this fluorescent tube 211,221,231 and 241; Thereby it can take into account the driving voltage that is adjusted to this fluorescent tube 211,221,231 and 241, avoids that covering other electric current influences the comprehensive adjustment to this fluorescent tube 211,221,231 and 241 luminosity greatly owing to a certain lamp tube current wherein.Therefore, control circuit for light source 200 of the present invention makes the whole light source system luminous more equably, effectively improves the luminous mass of whole lamp system, and then prolongs the useful life of each fluorescent tube.
Seeing also Fig. 3, is the circuit diagram of control circuit for light source second execution mode of the present invention.This control circuit for light source 300 also comprises a plurality of feedback circuits; With this first feedback circuit 310 is example; This control circuit for light source 300 is with the difference of this control circuit for light source 200: in this first feedback circuit 310; The low-pressure end of this first fluorescent tube 311 is connected to the negative pole of this first diode 312, and the positive pole of this first diode 312 is through these sampling resistor 316 ground connection, simultaneously through this first biasing resistor 313 of connecting each other and second biasing resistor, 315 ground connection.The first transistor 314 of this first power balancing circuit is the positive-negative-positive bipolar transistor; Its base stage is connected between this first biasing resistor 313 and this second biasing resistor 315; Its emitter is connected to the induction by current end 351 of this controller 350, and its collector electrode is connected to the emitter of the transistor seconds 324 of this second current balance circuit.In addition, in this control circuit for light source 300, the structure of other feedback circuit is identical with this first feedback circuit 310.
In this control circuit for light source 300, the current feedback of 350 pairs of each feedback circuits of this controller and the voltage sample of 360 pairs of each feedback circuits of this open loop protection circuit all are that the negative half-cycle at this high-frequency ac voltage carries out.When the input of this open loop protection circuit 360 all is in negative potential; It is to these controller 350 these first control signals of output; When this open loop protection circuit 360 detects its a certain input and is zero potential; It makes this controller 350 these control circuit for light source 300 entering guard modes of control rapidly just to these controller 350 these second control signals of output.
In addition, not to be confined to above execution mode said for control circuit for light source 200 of the present invention and 300.For example, in this control circuit for light source 200 and 300, the number of this feedback circuit is not limited to four, and they can also be a plurality of arbitrarily for other.With this control circuit for light source 200 is example; Its corresponding feedback circuit 210 of the circuit inner structure and this of these any a plurality of feedback circuits is identical; And in the current balance circuit of these any a plurality of feedback circuits; Adjacent two transistorized collector electrodes and emitter interconnect, and the transistorized collector electrode that is positioned at head end is connected to corresponding controller 250, is positioned at terminal transistorized grounded emitter.
Claims (9)
1. control circuit for light source; It comprises a controller and a plurality of light source; It is characterized in that: this control circuit for light source also comprises a plurality of current balance circuits, and each light source correspondence is connected to a current balance circuit, and these a plurality of current balance circuits are sampled to the luminosity signal of these a plurality of light sources; And sampled result is carried out obtaining a feedback signal after the balance adjustment output to this controller; This controller is regulated the luminous of this light source according to this feedback signal, and each current balance circuit comprises a biasing circuit and a positive-negative-positive bipolar transistor, and this transistorized base stage is connected to this biasing circuit; These a plurality of current balance circuits connect successively; Transistor in the current balance circuit of head end; Its collector electrode is connected with the induction by current end of this controller; Its emitter is connected with transistorized collector electrode in the next stage current balance circuit; Transistor in the terminal current balance circuit, its collector electrode is connected its grounded emitter with transistorized emitter in the upper level current balance circuit; Be in the transistor in the current balance circuit between head end and the end, its collector electrode is connected with transistorized emitter in the upper level current balance circuit, and its emitter is connected with transistorized collector electrode in the next stage current balance circuit.
2. control circuit for light source as claimed in claim 1 is characterized in that: this current balance circuit is connected to this light source through a diode, and the positive pole of this diode is connected with this light source, and its negative pole is connected to this bipolar transistor through this biasing circuit.
3. control circuit for light source as claimed in claim 1; It is characterized in that: this biasing circuit comprises one first biasing resistor and one second biasing resistor; And this first biasing resistor is connected between the base stage of this light source and this bipolar transistor, and this second biasing resistor is connected between the base stage and ground end of this bipolar transistor.
4. control circuit for light source as claimed in claim 1; It is characterized in that: this controller comprises an induction by current end and a luminance input; Wherein this induction by current end is used to receive this feedback signal; This luminance input is used to receive luminance signal, and this controller compares analysis with this feedback signal and this luminance signal of its reception, and regulates the luminous of this light source according to the comparative analysis result.
5. control circuit for light source as claimed in claim 1; It is characterized in that: this control circuit for light source also comprises an open loop protection circuit; This open loop protection circuit comprises an input and an output, and its input is connected to this current balance circuit, and its output is connected to this controller.
6. control circuit for light source; It comprises a controller and a plurality of light source; It is characterized in that: this control circuit for light source also comprises a plurality of current balance circuits that connect successively, the corresponding current balance circuit of each light source, and these a plurality of current balance circuits are sampled to the luminosity signal of these a plurality of light sources; And sampled result is carried out obtaining a feedback signal after the balance adjustment output to this controller; This controller is regulated the luminous of this light source according to this feedback signal, and each current balance circuit comprises a biasing circuit and a npn type bipolar transistor, and this transistorized base stage is connected to this biasing circuit; Transistor in the current balance circuit of head end; Its emitter is connected with the induction by current end of this controller; Its collector electrode is connected with transistorized emitter in the next stage current balance circuit; Transistor in the terminal current balance circuit, its emitter is connected its grounded collector with transistorized collector electrode in the upper level current balance circuit; Be in the transistor in the current balance circuit between head end and the end, its emitter is connected with transistorized collector electrode in the upper level current balance circuit, and its collector electrode is connected with transistorized emitter in the next stage current balance circuit.
7. control circuit for light source as claimed in claim 6 is characterized in that: this current balance circuit is connected to this light source through a diode, and the negative pole of this diode is connected with this light source, and its positive pole is connected to this bipolar transistor through this biasing circuit.
8. control circuit for light source as claimed in claim 6; It is characterized in that: this biasing circuit comprises one first biasing resistor and one second biasing resistor; And this first biasing resistor is connected between the base stage of this light source and this bipolar transistor, and this second biasing resistor is connected between the base stage and ground end of this bipolar transistor.
9. control circuit for light source as claimed in claim 6; It is characterized in that: this controller comprises an induction by current end and a luminance input; Wherein this induction by current end is used to receive this feedback signal; This luminance input is used to receive luminance signal, and this controller compares analysis with this feedback signal and this luminance signal of its reception, and regulates the luminous of this light source according to the comparative analysis result.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2007100760917A CN101351072B (en) | 2007-07-20 | 2007-07-20 | Control circuit for light source |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2007100760917A CN101351072B (en) | 2007-07-20 | 2007-07-20 | Control circuit for light source |
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| Publication Number | Publication Date |
|---|---|
| CN101351072A CN101351072A (en) | 2009-01-21 |
| CN101351072B true CN101351072B (en) | 2012-03-14 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2007100760917A Expired - Fee Related CN101351072B (en) | 2007-07-20 | 2007-07-20 | Control circuit for light source |
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| CN111542152A (en) * | 2020-05-22 | 2020-08-14 | 中国科学院半导体研究所 | Ultraviolet light source system with light intensity automatic feedback correction function and application thereof |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1515940A (en) * | 2002-11-20 | 2004-07-28 | ���ǵ�����ʽ���� | Lamp driver anjd back light assemlby and liquid crystal display device containing it |
| CN1617644A (en) * | 2003-11-14 | 2005-05-18 | 立锜科技股份有限公司 | Driving circuit for driving multi group DC light source |
-
2007
- 2007-07-20 CN CN2007100760917A patent/CN101351072B/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1515940A (en) * | 2002-11-20 | 2004-07-28 | ���ǵ�����ʽ���� | Lamp driver anjd back light assemlby and liquid crystal display device containing it |
| CN1617644A (en) * | 2003-11-14 | 2005-05-18 | 立锜科技股份有限公司 | Driving circuit for driving multi group DC light source |
Non-Patent Citations (1)
| Title |
|---|
| JP特开2005-310996A 2005.11.04 |
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| CN101351072A (en) | 2009-01-21 |
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