CN101662869B - Pulse constant-current source and direct constant-current source superposed circuit - Google Patents
Pulse constant-current source and direct constant-current source superposed circuit Download PDFInfo
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- CN101662869B CN101662869B CN2009103077907A CN200910307790A CN101662869B CN 101662869 B CN101662869 B CN 101662869B CN 2009103077907 A CN2009103077907 A CN 2009103077907A CN 200910307790 A CN200910307790 A CN 200910307790A CN 101662869 B CN101662869 B CN 101662869B
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Abstract
The invention relates to a pulse constant-current source and direct constant-current source superposed circuit which comprises a heavy current pulse constant-current source forming circuit and a low current pulse constant-current source forming circuit. The heavy current pulse constant-current source forming circuit comprises a heavy current voltage source, a pulse constant-current source control circuit and a pulse constant-current source control switch, and the low current pulse constant-current source forming circuit comprises a low current voltage source, a direct constant-current source control circuit and a direct constant-current source control switch. Negative electrodes of both voltage sources are grounded respectively and independently, a superposed switch is connected between two grounded terminals, and a control terminal of the superposed switch is connected with a control circuit controlled by the superposed switch. An adverse current preventing element is connected between the superposed switch and the negative grounded terminal of the heavy current voltage source and/or between the superposed switch and the negative grounded terminal of the low current voltage source, thus effectively avoiding interference on low direct current due to rising edge and falling edge of the heavy current pulse, and avoiding damage to the low current voltage source for the heavy pulse current is provided with the low current voltage source.
Description
Technical field
The present invention relates to a kind of drive circuit of light-emitting diode, relate in particular to the supercircuit of a kind of heavy current pulse constant-current source and little current DC constant-current source.
Background technology
Light-emitting diode for some special purposes; Like semiconductor laser diode, diode operation is being excited excited state when sending laser, need flow through very big electric current; This electric current can not be continuous direct current, otherwise laser diode is easy to the overpower cause thermal damage.During actual the use, the electric current of driving laser diode is a burst pulse type constant-current source, and duty ratio is very little, general maximum 20%, but electric current is all very big, from 20A to 250A, does not wait.Laser diode has the weak shortcoming that is highly brittle, and can not bear reverse voltage and reverse current exactly, and very low reverse voltage and reverse current will cause damage to it.So the rising and falling edges at heavy current pulse reverse voltage occurs in order to prevent the laser diode two ends, need apply the dc constant current power supply of a little electric current to laser diode, make its two ends have a little forward bias voltage.In addition; The directivity of laser, monochromaticjty, coherence are best in all light; Yet variation that drive current is very little or variation of temperature all can exert an influence to the monochromaticjty that diode sends laser; At this moment need be through drive current being finely tuned the monochromaticjty of regulating laser, little current DC constant-current source just can be used for realizing this function.
When reality is used; Heavy current pulse constant-current source and little current DC constant-current source need output simultaneously, are applied to above the laser diode, with respect to same load; The generation of big electric current needs the voltage source of high voltage, and the generation of little electric current only needs the voltage source of low voltage.Realize the method that big electric current (high voltage) and little electric current (low-voltage) superpose in same load, had following two kinds in the past:
First kind as shown in Figure 1, uses same voltage source Uin1, through the linear current stabilization circuit of two covers, forms heavy current pulse constant-current source and little current DC constant-current source respectively, and said two cover circuit common grounds are realized simple.Voltage source need be exported heavy current pulse, and its voltage will be than higher under identical load; And the voltage that little current DC produces in load is very low, and the most of voltage of voltage source is added on the dc constant current power supply control switch pipe S2, and so little current DC constant-current source forms circuit loss will be very big, and efficient is very low.
Second kind as shown in Figure 2; Use two voltage source Uin1 and Uin2; Come to form respectively heavy current pulse constant-current source and little current DC constant-current source, wherein the voltage of Uin1 is greater than the voltage of Uin2, and the anodal of two voltage sources all links to each other with the positive terminal of load; The negative pole of two voltage sources is connected with the load negative terminals through the series circuit of sampling resistor with the control switch pipe of correspondence respectively, and two voltage sources altogether.Like this when heavy current pulse constant-current source and little current DC constant-current source are exported simultaneously, switch S 4 conductings, Uin1 provides energy by voltage source; When having only little current DC to export, switch S 4 is broken off, and Uin2 provides energy by voltage source.Because the duty ratio of heavy current pulse is very little, this method can be raised the efficiency.But two voltage sources altogether; The block isolating circuit S4 and the D2 that need add more complicated each other; Also possibly occur the situation of heavy current pulse being provided and causing device failure by little current/voltage source; And the rising edge of pulse voltage, trailing edge are equivalent on load RL, produce voltage dithering than very fast; Because two voltage source voltage constants, two current sources are altogether, theoretical according to the kirchhoff voltage close loop, S2, the last voltage of R2 also can produce shake in the little current DC constant-current source formation circuit, cause the little current DC that flows through on it to produce shake.
Summary of the invention
The purpose of this invention is to provide a kind of pulsed constant current supply and dc constant current power supply supercircuit; Effectively to avoid heavy current pulse rising edge, trailing edge, avoid pulse high current to provide and cause the damage in little current/voltage source by little current/voltage source to the interference that little current DC causes.
For reaching the foregoing invention purpose; Technical program of the present invention lies in providing a kind of pulsed constant current supply and dc constant current power supply supercircuit; Comprise that mainly the heavy current pulse constant-current source forms circuit and little current DC constant-current source forms circuit; The heavy current pulse constant-current source forms circuit and mainly is made up of large-current electric potential source, pulse constant current source control circuit and pulsed constant current supply control switch; Little current DC constant-current source forms circuit and mainly is made up of little current/voltage source, dc constant current power supply control circuit and dc constant current power supply control switch; The negative pole in the negative pole of described large-current electric potential source and little current/voltage source is independent grounding respectively, is connected with the stack switch between two earth terminals, and the control end of this switch is connected with stack switch control control circuit; Control conducting or disconnection between two earth terminals, stack switch and pulse constant current source switch synchronization action; Be connected with between the minus earth end in stack switch and little current/voltage source and/or between the minus earth end in stack switch and little current/voltage source and prevent the electric current counterflow element, make electric current by the minus earth end in little current/voltage source minus earth end one-way flow to the large-current electric potential source.
The input signal of stack ON-OFF control circuit is provided by the pulse constant current source control circuit.
Be connected with anti-electric current counterflow element between the positive pole of large-current electric potential source and the positive pole of load.
Described stack switch is an electronic switching tube.
Described anti-electric current counterflow element is a diode, and is at least one.
The negative pole in the negative pole of large-current electric potential source and little current/voltage source difference independent grounding among the present invention; Stack switch and pulsed constant current supply control switch synchronization action; Realize conducting or disconnection between two earth terminals; So the rising edge of pulse voltage, trailing edge just are applied on the stack switch at the voltage dithering that produces in the load, the voltage on the little current DC constant-current circuit just can not produce shake, and the little current DC that guarantees to flow through on it keeps invariable; Be connected with anti-electric current counterflow element between the minus earth end in stack switch and little current/voltage source and/or between the minus earth end in stack switch and little current/voltage source; Make electric current by the minus earth end in little current/voltage source minus earth end one-way flow to the large-current electric potential source; Can prevent that electric current from being flowed to the minus earth end in little current/voltage source by the minus earth end of large-current electric potential source; When load value output is very little or heavy current pulse climb and set up in the process; Can avoid heavy current pulse to provide, thereby can avoid damaging little current/voltage source by little current/voltage source; In addition; The input signal of stack ON-OFF control circuit is provided by the pulse constant current source control circuit; Guarantee the synchronous of stack switch and the action of pulsed constant current supply control switch, can further avoid the voltage dithering on the little current DC constant-current circuit that pulse voltage causes.
Description of drawings
Fig. 1 is the supercircuit that uses a voltage source in the prior art;
Fig. 2 is the supercircuit that uses two voltage sources in the prior art;
Fig. 3 is pulsed constant current supply of the present invention and dc constant current power supply supercircuit;
Fig. 4 is the simplified electrical circuit diagram of heavy current pulse constant-current source of the present invention when exporting separately;
Fig. 5 is the oscillogram of heavy current pulse constant-current source of the present invention each signaling point when exporting separately;
Fig. 6 is the simplification circuit of the little current DC constant-current source of the present invention when exporting separately;
Fig. 7 is pulsed constant current supply of the present invention and the dc constant current power supply fundamental diagram when exporting simultaneously;
Fig. 8 is the oscillogram of pulsed constant current supply of the present invention and dc constant current power supply each signaling point when exporting simultaneously.
Embodiment
As shown in Figure 3, the heavy current pulse constant-current source forms in the circuit 1, and Uin1 is the large-current electric potential source, and its minus earth end is GND1, is connected with diode D1 between its positive pole and the load positive pole, guarantees that electric current is flowed to the positive pole of load by the positive pole of voltage source Uin1; The negative pole of load is connected the negative pole of voltage source Uin1 successively with sampling resistor R1 through electronic impulse constant-current source control switch pipe S1; Pulse constant current source control circuit sampled signal input is connected in the current input terminal of sampling resistor R1; Control signal output ends connects the control end of electronic impulse constant-current source control switch pipe S1; The current IS 1 of pulse constant current source control circuit sample streams over-sampling resistance R 1; And with the given signal of pulse current relatively, output drive signal DRV1 comes driving pulse constant-current source control switch pipe S1.
Little current DC constant-current source forms in the circuit 2, and Uin2 is little current/voltage source, and its minus earth end is GND2, is connected with diode D2 between its positive pole and the load positive pole, guarantees that electric current is flowed to the positive pole of load by the positive pole of voltage source Uin2; The negative pole of load is connected the negative pole of voltage source Uin2 successively with sampling resistor R2 through electronics dc constant current power supply control switch pipe S2; Little current DC constant current source control circuit sampled signal input is connected in the current input terminal of sampling resistor R2; Control signal output ends connects the control end of electronics dc constant current power supply control switch pipe S2; The current IS 2 of little current DC constant current source control circuit sample streams over-sampling resistance R 2; And with the given signal of direct current relatively, output drive signal DRV2 drives dc constant current power supply control switch pipe S2.
The supercircuit 3 of heavy current pulse constant-current source and little current DC constant-current source; The current input terminal of stack switching tube S3 links together through diode D3 and GND2; The current output terminal of S3 directly connects GND1, and the control end of S3 connects stack switch controlled circuit; The direction of diode D3 is to make electric current flow to GND1 from GND2, can prevent that heavy current pulse from being provided by little current/voltage source Uin2; Stack switch controlled circuit provides the drive signal of stack switching tube S3, and the input signal of control circuit is that pulse current is given.
Set forth the principle and the course of work of circuit according to the invention in detail below in conjunction with Fig. 4 to Fig. 8:
1, the heavy current pulse constant-current source is exported separately, and at this moment little current DC constant-current source forms circuit 2 and do not work, and circuit can be reduced to circuit shown in Figure 4, each point waveform such as Fig. 5.The given IG1 of pulse current after its amplitude, duty ratio, frequency setting are good, gets into the pulse constant current source control circuit.In t0～t1 pulse current given high level stage, sampling resistor R1 samples through the pulse current IL on the load RL, obtains IS1.In the pulse constant current source control circuit, given IG1 of electric current and current sample IS1 carry out closed loop relatively, obtain drive signal DRV1; Be used for driving linear constant current tube S1; S1 is an electronic switching tube, through the amplitude of its pulse drive signal of closed-loop control DRV1, makes it be operated in linear constant current state.In the given high level of the pulse current stage; Stack switch controlled circuit output high level drive signal DRV3 drives stack switching tube S3 and makes its saturation conduction, is equivalent to short circuit behind the stack switching tube S3 saturation conduction; Because the existence of diode D3 can prevent that electric current from flowing to GND2 by GND1; Therefore when load value output is very little or heavy current pulse climb and set up in the process, D3 can avoid heavy current pulse to be provided by little current/voltage source Uin2, thereby can avoid damaging little current/voltage source circuit.
In t1～t2 pulse current given low level stage, pulsed constant current supply control switch pipe S1, stack switching tube S3 all close the output of no pulse electric current.
The independent output state of heavy current pulse constant-current source, stack switch controlled circuit is all worked with stack switching tube S3, but does not have electric current to flow through stack switching tube S3.
2, little current DC constant-current source is exported separately; At this moment heavy current pulse constant-current source formation circuit 1 is not worked, and supercircuit 3 is not worked yet, and circuit can be reduced to circuit as shown in Figure 6; The waveform of each signaling point is direct current; The dc constant current power supply control circuit compares given IG2 of little current DC and current sample IS2 closed loop, obtains drive signal DRV2 and drives linear dc constant current power supply control switch pipe S2, makes the electric current I that flows through load
LRemain unchanged.
3, heavy current pulse constant-current source and little current DC constant-current source are exported simultaneously; At this moment heavy current pulse constant-current source formation circuit 1, little current DC constant-current source form circuit 2, supercircuit 3 is all worked; Guarantee that when pulse was exported, little current DC constant-current source also can be stablized output.Circuit working principle such as Fig. 7, the each point waveform is as shown in Figure 8, and the given IG1 of heavy current pulse electric current is the rectangular pulse waveform, and its amplitude, frequency, duty ratio are by external setting-up; The given IG2 of little current DC is a DC level.
In t0～t1 pulse current given high level stage, this moment, little current DC was given constant.Pulse constant current source control circuit output control signal DRV1 driving pulse constant-current source control switch pipe S1 makes the current IS 1 that flows through on it invariable; The open the light input signal of management and control system circuit of stack is also given for pulse current, as long as signal level is greater than zero, control circuit is just exported saturated high level drive signal DRV3, drives the switching tube S3 saturation conduction that superposes.Behind the S3 saturation conduction, two ground of GND2 and GND1 just link together through diode D3.Because Uin1 voltage is higher than Uin2 voltage, after the stack switching tube S3 conducting, diode D2 oppositely ends, and the voltage source that little current DC constant-current source forms circuit is provided by voltage source Uin1.The voltage source that little current DC constant-current source forms circuit becomes high pressure Uin1 by low pressure Uin2, in order to guarantee to flow through the electric current I of dc constant current power supply control switch pipe S2
2Constant, drive signal DRV2 amplitude descends.There is following relation in this stage:
I
2＝0
I
S2＝I
S3
I
L＝I
1＝I
S1+I
S2
Realized the stack of heavy current pulse constant-current source and little current DC constant-current source.
In t1～t2 pulse current given low level stage, drive signal DRV1, DRV3 are low level, and linear constant current tube S1, stack switching tube S3 all close, and no current flows through S1 and S3.Because stack switching tube S3 closes; The ground GND1 of two voltage sources and GND2 break off; The supply voltage source that little current DC constant-current source forms circuit becomes low-voltage Uin2 by high voltage Uin1; So it is the amplitude of dc constant current power supply control switch pipe S2 drive signal DRV2 will be uprised by low, constant with the current IS 2 of the sampling resistor R2 that guarantees to flow through.In this stage, the current IS 1 that flows through sampling resistor R1 is zero, and following relation is arranged between each electric current:
I
1＝I
S2＝I
S3＝0
I
L＝I
2＝I
S2
Claims (5)
1. pulsed constant current supply and dc constant current power supply supercircuit; Comprise that the heavy current pulse constant-current source forms circuit and little current DC constant-current source forms circuit; The heavy current pulse constant-current source forms circuit and comprises large-current electric potential source, pulse constant current source control circuit and pulsed constant current supply control switch; Little current DC constant-current source forms circuit and comprises little current/voltage source, dc constant current power supply control circuit and dc constant current power supply control switch; It is characterized in that: the negative pole in the negative pole of described large-current electric potential source and little current/voltage source is independent grounding respectively; Be connected with the stack switch between two earth terminals; The control end of this switch is connected with the stack ON-OFF control circuit, controls conducting or disconnection between two earth terminals, stack switch and pulsed constant current supply control switch synchronization action; Be connected with between the minus earth end in stack switch and little current/voltage source and/or between the minus earth end of stack switch and large-current electric potential source and prevent the electric current counterflow element, make electric current by the minus earth end in little current/voltage source minus earth end one-way flow to the large-current electric potential source.
2. pulsed constant current supply as claimed in claim 1 and dc constant current power supply supercircuit is characterized in that: the input signal of stack ON-OFF control circuit is provided by the pulse constant current source control circuit.
3. pulsed constant current supply as claimed in claim 2 and dc constant current power supply supercircuit is characterized in that: be connected with anti-electric current counterflow element between the positive pole of said large-current electric potential source and the positive pole of load.
4. like each described pulsed constant current supply of claim 1 to 3 and dc constant current power supply supercircuit, it is characterized in that: described stack switch is an electronic switching tube.
5. pulsed constant current supply as claimed in claim 4 and dc constant current power supply supercircuit is characterized in that: described anti-electric current counterflow element is a diode.
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| CN2009103077907A CN101662869B (en) | 2009-09-25 | 2009-09-25 | Pulse constant-current source and direct constant-current source superposed circuit |
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| CN2009103077907A CN101662869B (en) | 2009-09-25 | 2009-09-25 | Pulse constant-current source and direct constant-current source superposed circuit |
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| CN101662869A CN101662869A (en) | 2010-03-03 |
| CN101662869B true CN101662869B (en) | 2012-11-28 |
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| CN104600855B (en) * | 2014-12-30 | 2017-02-01 | 南京航空航天大学 | Laser driving power supply and method for realizing power signal composite transmission thereof |
| JP7140140B2 (en) * | 2017-11-21 | 2022-09-21 | ソニーグループ株式会社 | Sensor device and sensing method |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1211094A (en) * | 1997-09-09 | 1999-03-17 | 三菱电机株式会社 | Power source controller for laser diode |
| CN1505226A (en) * | 2002-11-29 | 2004-06-16 | 松下电器产业株式会社 | Laser diode driving device |
| CN201174795Y (en) * | 2007-10-30 | 2008-12-31 | 河南大学 | Driving apparatus of laser diode series group |
-
2009
- 2009-09-25 CN CN2009103077907A patent/CN101662869B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1211094A (en) * | 1997-09-09 | 1999-03-17 | 三菱电机株式会社 | Power source controller for laser diode |
| CN1505226A (en) * | 2002-11-29 | 2004-06-16 | 松下电器产业株式会社 | Laser diode driving device |
| CN201174795Y (en) * | 2007-10-30 | 2008-12-31 | 河南大学 | Driving apparatus of laser diode series group |
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| CN101662869A (en) | 2010-03-03 |
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Effective date of registration: 20131129 Address after: No. 1298 Xuchang City, Henan province 461000 XJ Avenue Patentee after: Xuji Electric Co., Ltd. Patentee after: Xuji Electric Power Co., Ltd. Patentee after: State Grid Corporation of China Address before: No. 1298 Xuchang City, Henan province 461000 XJ Avenue Patentee before: Xuji Group Co., Ltd. Patentee before: Xuji Electric Power Co., Ltd. Patentee before: State Grid Corporation of China |