CN207039961U - One kind simulation DC light modulations turn pwm circuit - Google Patents
One kind simulation DC light modulations turn pwm circuit Download PDFInfo
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- CN207039961U CN207039961U CN201720919661.3U CN201720919661U CN207039961U CN 207039961 U CN207039961 U CN 207039961U CN 201720919661 U CN201720919661 U CN 201720919661U CN 207039961 U CN207039961 U CN 207039961U
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Abstract
The utility model discloses one kind simulation DC light modulations to turn pwm circuit, including comparator U1, operational amplifier U3 and constant-current source, the electrode input end of the comparator U1 is electrically connected by circuit with power supply V2 positive pole, comparator U1 side is additionally provided with electric capacity C1, resistance R1 and resistance R3, the negative input of the operational amplifier U3 is electrically connected by circuit with comparator U1 negative input, operational amplifier U3 side is additionally provided with resistance R4, resistance R5 and resistance R6, and the constant-current source includes triode Q1, resistance R9, resistance R8 and resistance R7.Comparator U1 input receives the signal Vtri signals from sawtooth waveforms and compared with DC_IN, so comparator U1 can be made to export different PWMDuty, then the light modulation pin/COMP/CTRL or equivalent inputted by optocoupler to control IC has the pin that control IC drives output function；With the change of DC_IN signal levels, sawtooth waveforms is cut so as to obtain the output of different PWM duty cycles.
Description
Technical field
LED drive power technical field is the utility model is related to, especially a kind of simulation DC light modulations turn pwm circuit.
Background technology
Light modulation for LED, what industry commonly recommended is PWM light modulation, its be compared to simulation light modulation advantage simply enumerate it is several
Bar is as follows；One will not produce any chromatogram skew, because LED is always worked between full amplitude voltage and 0.Two can have it is high
Light modulation accuracy.Because impulse waveform can control very high precision completely.Three can be combined with digital control technology
To be controlled.Even if four dim in very large range, scintillation will not also occur.Because the work of constant-current source will not be changed
Condition (step-up ratio or step-down ratio).And these are exactly the shortcomings that DC simulations dim, chromatogram is drifted about, and precision is not high, it is difficult in numeral
Control circuit interface, ditty photophase be not easily high by noise jamming, light modulation precision.
Utility model content
The purpose of this utility model is that providing a kind of simulation DC light modulations turns pwm circuit, and cost is low, and material is versatile,
Flexible setting for parameters, design flexibility is high, to solve the problems, such as in above-mentioned background technology.
To achieve the above object, the utility model provides following technical scheme：
One kind simulation DC light modulations turn pwm circuit, including comparator U1, operational amplifier U3 and constant-current source, the comparator
U1 electrode input end is electrically connected by circuit with power supply V2 positive pole, and comparator U1 side is additionally provided with electric capacity C1, resistance
R1 and resistance R3, the electric capacity C1 are connected electrically in by branch circuit on the circuit that comparator U1 connected, and the resistance R1 leads to
The side that parallel circuit is connected in parallel on electric capacity C1 is crossed, the resistance R3 is electrically connected by branch circuit with comparator U1 output end,
The negative input of the operational amplifier U3 is electrically connected by circuit with comparator U1 negative input, operational amplifier U3
Side be additionally provided with resistance R4, resistance R5 and resistance R6, the resistance R4 are connected in parallel on operational amplifier U3 by parallel circuit
Electrode input end where circuit on, the resistance R5 is connected on operational amplifier U3 electrode input end by branch circuit
On the circuit at place, the resistance R6 is connected electrically on the circuit where operational amplifier U3 electrode input end, the constant current
Source includes triode Q1, resistance R9, resistance R8 and resistance R7, the collector of the triode Q1 and passes through circuit and operational amplifier U3
Electrode input end electrical connection, triode Q1 emitter-base bandgap grading goes out to hold and electrically connected by circuit and operational amplifier U3's, the resistance
R9 is connected electrically on the circuit where triode Q1 emitter-base bandgap grading end, and the resistance R8 is connected electrically in triode Q1 by branch circuit
Emitter-base bandgap grading end where circuit on, the resistance R7 is connected on the circuit where resistance R8.
As further program of the utility model：It is also electric on the circuit that the electrode input end of the comparator U1 is connected
It is connected with resistance R2.
As further program of the utility model：The comparator U1 and operational amplifier U3 model is
LT1017。
As further program of the utility model：The model 2N3906 of the triode Q1.
As further program of the utility model：The triode Q1 is also electric on circuit send out big device U3 and be connected with calculating
It is connected with electric capacity C2.
As further program of the utility model：On circuit where the resistance R7 and resistance R8 also by circuit with
Triode Q1 base stage electrical connection.
Compared with prior art, the beneficial effects of the utility model are as follows：
This simulation DC light modulations turn pwm circuit, and comparator U1 input receives the signal Vtri signals from sawtooth waveforms simultaneously
Compare with DC_IN, so comparator U1 can be made to export different PWM Duty, then inputted by optocoupler to control IC light modulation
Pin/COMP/CTRL or equivalent has the pin of control IC driving output functions；With the change of DC_IN signal levels, sawtooth waveforms is cut
So as to obtain the output of different PWM duty cycles.
Brief description of the drawings
Fig. 1 is circuit theory diagrams of the present utility model.
In figure：1 constant-current source, comparator U1, operational amplifier U3, power supply V2, resistance R2, electric capacity C1, resistance R1 and resistance
R3, resistance R4, resistance R5, resistance R6, triode Q1, resistance R9, resistance R8, resistance R7, electric capacity C2.
Embodiment
Below in conjunction with the accompanying drawing in the utility model embodiment, the technical scheme in the embodiment of the utility model is carried out
Clearly and completely describing, it is clear that described embodiment is only the utility model part of the embodiment, rather than whole
Embodiment.Based on the embodiment in the utility model, those of ordinary skill in the art are not under the premise of creative work is made
The every other embodiment obtained, belong to the scope of the utility model protection.
Referring to Fig. 1, in the utility model embodiment, one kind simulation DC light modulations turn pwm circuit, including comparator U1, fortune
Calculate amplifier U3 and constant-current source 1, and comparator U1 and operational amplifier U3 model is LT1017, comparator U1 positive pole
Input is electrically connected by circuit with power supply V2 positive pole, and is also electrically connected on the circuit that is connected of comparator U1 electrode input end
Resistance R2 is connected to, comparator U1 side is additionally provided with electric capacity C1, resistance R1 and resistance R3, and electric capacity C1 is electrically connected by branch circuit
It is connected on the circuit that comparator U1 is connected, resistance R1 is connected in parallel on electric capacity C1 side by parallel circuit, and resistance R3 is by dividing
Branch circuit electrically connects with comparator U1 output end, and operational amplifier U3 negative input is negative by circuit and comparator U1's
Pole input electrical connection, operational amplifier U3 side are additionally provided with resistance R4, resistance R5 and resistance R6, and resistance R4 passes through simultaneously
Join circuit in parallel on the circuit where operational amplifier U3 electrode input end, resistance R5 is connected on computing by branch circuit
On circuit where amplifier U3 electrode input end, resistance R6 is connected electrically in where operational amplifier U3 electrode input end
Circuit on, constant-current source 1 includes triode Q1, resistance R9, resistance R8 and resistance R7, and triode Q1 model 2N3906,
Triode Q1 collector is electrically connected by circuit with operational amplifier U3 electrode input end, and triode Q1 sends out device U3 big with calculating
Electric capacity C2 is also electrically connected with the circuit connected, electric capacity C2 is charged by triode Q1, triode Q1 emitter-base bandgap grading passes through electricity
Road and operational amplifier the U3 end that goes out are electrically connected, and resistance R9 is connected electrically on the circuit where triode Q1 emitter-base bandgap grading end, is passed through
Resistance R9 size can change the output current size of constant-current source, and resistance R8 is connected electrically in triode Q1's by branch circuit
On circuit where emitter-base bandgap grading end, resistance R7 is connected on the circuit where resistance R8, on the circuit where resistance R7 and resistance R8
Also electrically connected by circuit with triode Q1 base stage.
This simulation DC light modulations turn pwm circuit, and when power supply V2 starts, electric capacity C2 is 0V and operational amplifier U3 positive pole
Input is 10V, so triode Q1 electric current original starts to charge to electric capacity C2；When electric capacity C2 current potential is charged to 10V, computing
Amplifier U3 outputs switch to low, and now the current potential on electric capacity C2 will pass through diode D1 (Schottky) to 0.3V.Now, computing is put
The current potential of big device U3 electrode input end is because output is 0V, so the near 0.3V of the pin, therefore the current potential on electric capacity C2 only can
0.3V is discharged to, and then operational amplifier U3 outputs is switched to high (15V) output again, so triode Q1 will continue
C2 is charged, so repeatedly.
This simulation DC light modulations turn pwm circuit, and comparator U1 input receives the signal Vtri signals from sawtooth waveforms simultaneously
Compare with DC_IN, so comparator U1 can be made to export different PWM Duty, then inputted by optocoupler to control IC light modulation
Pin/COMP/CTRL or equivalent has the pin of control IC driving output functions；With the change of DC_IN signal levels, sawtooth waveforms is cut
So as to obtain the output of different PWM duty cycles.
In summary：Simulation DC light modulations turn pwm circuit, and a DC- is formed by general amplifier and resistance capacitance
PWM converter.Cost is low, and material is versatile, flexible setting for parameters, and design flexibility is high.Amplitude, frequency, dutycycle can be with
It is any to set.
It is obvious to a person skilled in the art that the utility model is not limited to the details of above-mentioned one exemplary embodiment, and
And in the case of without departing substantially from spirit or essential attributes of the present utility model, it can realize that this practicality is new in other specific forms
Type.Therefore, no matter from the point of view of which point, embodiment all should be regarded as exemplary, and is nonrestrictive, this practicality is new
The scope of type limits by appended claims rather than described above, it is intended that the equivalency fallen in claim is contained
All changes in justice and scope are included in the utility model.Any reference in claim should not be considered as limitation
Involved claim.
Moreover, it will be appreciated that although the present specification is described in terms of embodiments, not each embodiment is only wrapped
Containing an independent technical scheme, this narrating mode of specification is only that those skilled in the art should for clarity
Using specification as an entirety, the technical solutions in the various embodiments may also be suitably combined, forms those skilled in the art
It is appreciated that other embodiment.
Claims (6)
1. one kind simulation DC light modulations turn pwm circuit, including comparator U1, operational amplifier U3 and constant-current source (1), its feature exist
In：The electrode input end of the comparator U1 is electrically connected by circuit with power supply V2 positive pole, and comparator U1 side is also set up
There are electric capacity C1, resistance R1 and resistance R3, the electric capacity C1 to be connected electrically in by branch circuit on the circuit that comparator U1 connected,
The resistance R1 is connected in parallel on electric capacity C1 side by parallel circuit, and the resistance R3 is defeated by branch circuit and comparator U1's
Going out end electrical connection, the negative input of the operational amplifier U3 is electrically connected by circuit with comparator U1 negative input,
Operational amplifier U3 side is additionally provided with resistance R4, resistance R5 and resistance R6, and the resistance R4 is connected in parallel on by parallel circuit
On circuit where operational amplifier U3 electrode input end, the resistance R5 is connected on operational amplifier U3 by branch circuit
Electrode input end where circuit on, the resistance R6 is connected electrically in the circuit where operational amplifier U3 electrode input end
On, the constant-current source (1) includes triode Q1, resistance R9, resistance R8 and resistance R7, the collector of the triode Q1 and passes through circuit
Electrically connected with operational amplifier U3 electrode input end, triode Q1 emitter-base bandgap grading goes out end electricity by circuit and operational amplifier U3's
Connection, the resistance R9 are connected electrically on the circuit where triode Q1 emitter-base bandgap grading end, and the resistance R8 passes through branch circuit electricity
It is connected on the circuit where triode Q1 emitter-base bandgap grading end, the resistance R7 is connected on the circuit where resistance R8.
2. a kind of simulation DC light modulations according to claim 1 turn pwm circuit, it is characterised in that：The comparator U1 is just
Resistance R2 is also electrically connected with the circuit that pole input is connected.
3. a kind of simulation DC light modulations according to claim 1 turn pwm circuit, it is characterised in that：The comparator U1 and fortune
The model for calculating amplifier U3 is LT1017.
4. a kind of simulation DC light modulations according to claim 1 turn pwm circuit, it is characterised in that：The type of the triode Q1
Number it is 2N3906.
5. a kind of simulation DC light modulations according to claim 1 turn pwm circuit, it is characterised in that：The triode Q1 is with calculating
Electric capacity C2 is also electrically connected with the circuit sent out device U3 big and connected.
6. a kind of simulation DC light modulations according to claim 1 turn pwm circuit, it is characterised in that：Resistance R7 and resistance R8 institutes
Circuit on also electrically connected by circuit with triode Q1 base stage.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720919661.3U CN207039961U (en) | 2017-07-26 | 2017-07-26 | One kind simulation DC light modulations turn pwm circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720919661.3U CN207039961U (en) | 2017-07-26 | 2017-07-26 | One kind simulation DC light modulations turn pwm circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN207039961U true CN207039961U (en) | 2018-02-23 |
Family
ID=61462686
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201720919661.3U Active CN207039961U (en) | 2017-07-26 | 2017-07-26 | One kind simulation DC light modulations turn pwm circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN207039961U (en) |
-
2017
- 2017-07-26 CN CN201720919661.3U patent/CN207039961U/en active Active
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