CN206894949U - A kind of inexpensive current constant control lighting circuit - Google Patents
A kind of inexpensive current constant control lighting circuit Download PDFInfo
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- CN206894949U CN206894949U CN201720567567.6U CN201720567567U CN206894949U CN 206894949 U CN206894949 U CN 206894949U CN 201720567567 U CN201720567567 U CN 201720567567U CN 206894949 U CN206894949 U CN 206894949U
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Abstract
It the utility model is related to a kind of inexpensive current constant control lighting circuit, including adjusting control circuit, comparison circuit, mirror-image constant flow source, LED and the current-limiting resistance being sequentially connected electrically；Comparison circuit includes transistor Q3, resistance R5 and R6, and resistance R5 one end connects the output end of adjusting control circuit, and the other end connects resistance R6 and transistor Q3 colelctor electrode, the grounded emitter of resistance the R6 other end and transistor Q3 respectively；Mirror-image constant flow source includes transistor Q4 and resistance R7, transistor Q4 colelctor electrode is connected with LED negative electrode, transistor Q4 emitter stage connection resistance R7, resistance R7 other ends ground connection, transistor Q4 base stage is connected with transistor Q3 colelctor electrode, LED anode connection current-limiting resistance；Electric capacity C1 is connected between transistor Q4 base stage and transistor Q3 base stage.The utility model has that low cost, tunable optical, Electro Magnetic Compatibility be good, the advantage of constant current output flicker free.
Description
Technical field
Vehicle electronics technical field is the utility model is related to, specifically a kind of inexpensive current constant control lighting circuit.
Background technology
With the continuous development of automobile industry, vehicle electronics technology is maked rapid progress, on the premise of high quality requirement is met,
Also pursue the benefit of low cost.Back lighting for vehicle electronics, following five kinds of technical schemes are mainly used in the prior art
Realize, its advantage and disadvantage is had nothing in common with each other：
Scheme one：Using current-limiting resistance（Such as Fig. 1）.The advantages of program is that cost is relatively low.Shortcoming is that have fluctuation in power supply
When, when such as prescribing fire, back lighting can flash, and not possess dimming function.
Scheme two：Using the enabled illumination of NPN triode（Such as Fig. 2）.Advantage is that cost is low, it is possible to achieve light modulation；Shortcoming is
When power supply has fluctuation, when such as prescribing fire, back lighting can flash.
Scheme three：Using the enabled illumination of PNP triode（Such as Fig. 3）.Advantage is that cost is low, it is possible to achieve light modulation；For
For Layout, it is easier to connect up than scheme two, it is easier to reach a good electromagnetic compatibility characteristic；Shortcoming is that have ripple in power supply
When dynamic, when such as prescribing fire, back lighting can flash；And use a triode than scheme more than two, cost is slightly expensive.
Scheme four：Using constant pressure source IC circuits, constant pressure output is realized to drive lighting circuit（Such as Fig. 4）.Advantage is to pass through
Booster circuit, a constant voltage is increased to, then drives lighting circuit again, even if power supply has fluctuation, booster voltage is basic
It is constant, illumination output is not influenceed finally；Shortcoming is cost height, in order to improve power work efficiency, it is necessary to many LED strips connection,
When there are indivedual LED to damage, whole branch road is just caused not work, then illumination, which is gone out, just goes out a piece of, has a strong impact on electric equipment products
Work.
Scheme five：Using constant-current source IC circuits, pass through the existing constant current output of OUT terminal cause for gossip（Such as Fig. 5）.Advantage is to pass through constant current
Circuit is provided with a constant current, then drives lighting circuit again, even if power supply has fluctuation, constant output current, and not shadow
Ring illumination output；Shortcoming is cost height, input voltage is required, not only cost is higher, and Electro Magnetic Compatibility is also poor, and right
Layout requirement is higher.
There is certain weak point in above-mentioned prior art, in order to cover the shortage, inventor is studied this,
An effective solution is proposed, this case is given birth to therefrom.
Utility model content
The purpose of this utility model be to provide a kind of constant current output, have dimming function, electromagnetic compatibility effect be good, cost compared with
Low lighting circuit.
To achieve these goals, technical scheme is used by the utility model：
A kind of inexpensive current constant control lighting circuit, including adjusting control circuit, comparison circuit, the mirror being sequentially connected electrically
As constant-current source, LED and current-limiting resistance；The comparison circuit includes transistor Q3, resistance R5 and R6, the connection light modulation of resistance R5 one end
The output end of control circuit, the other end connect resistance R6 and transistor Q3 colelctor electrode, resistance the R6 other end and crystalline substance respectively
Body pipe Q3 grounded emitter；The mirror-image constant flow source includes transistor Q4 and resistance R7, transistor Q4 colelctor electrode and LED's
Negative electrode is connected, transistor Q4 emitter stage connection resistance R7, resistance R7 other ends ground connection, transistor Q4 base stage and transistor Q3
Colelctor electrode be connected, LED anode connection current-limiting resistance；Electricity is connected between transistor Q4 base stage and transistor Q3 base stage
Hold C1.
The transistor arrived used in the comparison circuit and mirror-image constant flow source uses NPN transistor.
The illumination output circuit being made up of mirror-image constant flow source, LED and current-limiting resistance is one group.
The illumination output circuit being made up of mirror-image constant flow source, LED and current-limiting resistance is direct with comparison circuit to be multigroup
Connected first group is image reference constant-current source, and other every group formed in parallel with first group illuminates output branch circuit, and
Base stage phase of the transistor base of mirror-image constant flow source with transistor in first group of image reference constant-current source in each branch circuit
Even.
The adjusting control circuit includes NPN transistor Q1, PNP transistor Q2, resistance R1 to R4, resistance R1 and resistance R2
Series connection, resistance R1 other end connection power supply and transistor Q1 emitter stage, resistance R2 other end connection transistor Q2 collection
Electrode, resistance R3 one end connection illumination driving Enable Pin, other end connection transistor Q2 base stage, resistance R4 one end connection crystal
Pipe Q2 base stage, other end ground connection, transistor Q2 grounded emitter, transistor Q1 colelctor electrode are connected with resistance R5.
Vehicle-mounted lighting circuit provided by the utility model forms mirror-image constant flow source knot compared with prior art, using transistor
Structure realizes constant current output, and cost is far below the constant-current driven chip cost used in the prior art；The same of dimming function can be realized
When there is preferable Electro Magnetic Compatibility；Requirement to input supply voltage is relatively low, and back lighting flicker free phenomenon；The photograph of formation
Bright output branch road can freely increase and decrease, and autgmentability is strong.
The utility model is further elaborated below by way of the drawings and specific embodiments.
Brief description of the drawings：
Fig. 1 is the circuit diagram of prior art one；
The circuit diagram of Fig. 2 prior arts two；
The circuit diagram of Fig. 3 prior arts three；
The circuit diagram of Fig. 4 prior arts four；
The circuit diagram of Fig. 5 prior arts five；
Fig. 6 is circuit diagram of the present utility model.
Embodiment：
As shown in fig. 6, vehicle-mounted lighting circuit provided by the utility model, can be divided into what is be sequentially connected electrically by functional unit
Adjusting control circuit, comparison circuit, mirror-image constant flow source, illuminating device LED and current-limiting resistance.Wherein, mirror-image constant flow source, LED and
Current-limiting resistance forms illumination output circuit, and the illumination output circuit can only set one group, can also be set regarding real needs more
Group is parallel with one another to form illumination output branch circuit with this, and the present embodiment is subject to exemplified by forming multigroup illumination output branch circuit
It is described in detail.The specific annexation of above-mentioned lighting circuit and used component combination Fig. 6 are described as follows：
Adjusting control circuit is mainly made up of NPN transistor Q1, PNP transistor Q2, resistance R1 to R4, wherein resistance R1 and
Resistance R2 connects, resistance R1 other end connection power supply and transistor Q1 emitter stage, resistance R2 other end connection transistor
Q2 colelctor electrode, resistance R3 one end connection illumination driving Enable Pin, other end connection transistor Q2 base stage, resistance R4 one end connects
Transistor Q2 base stage is connect, the other end is grounded, transistor Q2 grounded emitter, in transistor Q1 colelctor electrode and comparison circuit
Resistance R5 be connected.
Comparison circuit is mainly made up of resistance R5, R6 and NPN transistor Q3, and the resistance R5 other end connects resistance R6 respectively
With transistor Q3 colelctor electrode, the grounded emitter of resistance the R6 other end and transistor Q3.
First group of mirror-image constant flow source being joined directly together with comparison circuit is referred to as image reference constant-current source, multigroup branch thereafter
Referred to as mirror-image constant flow source, the difference being distinguish between with this in its connection.But either image reference constant-current source is still used as and divided
The mirror-image constant flow source of branch, it is formed by a NPN transistor and a resistance, the emitter stage of the transistor and one end of resistance
Connection, the other end ground connection of resistance.And the colelctor electrode connection LED of transistor negative electrode, LED anode connection current-limiting resistance.
Each group of illumination output circuit connects in the manner described above, and difference is：As in first group of image reference constant-current source
Transistor Q4 its base stage be connected with the colelctor electrode of transistor Q3 in comparison circuit, and transistor Q3 base stage is with transistor Q4's
Emitter stage is connected, and is connected with electric capacity C1 between transistor Q4 base stage and transistor Q3 base stage；Exported as illumination
Each group of mirror-image constant flow source of branch circuit, the base of the base stage of the transistor Q5 to Qn in its mirror-image constant flow source with transistor Q4
Extremely it is connected.
Lighting circuit with said structure, its operation principle are described as follows：When " illumination driving Enable Pin " the high electricity of input
Usually, transistor Q2 is turned on, and transistor Q1 base stage is dragged down so that transistor Q1 is turned on, and " power supply " voltage passes through Q1
Output voltage, resistance R5 is flowed through, to network node " reference voltage "（Voltage between R5 and Q3 colelctor electrodes is reference voltage）.
In the case of being not provided with electric capacity C1, when lighting circuit just starts, transistor Q3 base stages are dragged down by resistance R7, and transistor Q3 is cut
Only, " reference voltage " is not pulled low as high level.The voltage of " reference voltage " is given to transistor Q4 base stages, transistor Q4,
Q5 ... Qn is turned on, and LED is lighted.Voltage Feedback is converted to crystal after wherein flowing through resistance R7 by transistor Q4 electric current
Pipe Q3.When the electric current on transistor Q4 branch roads exceedes the threshold values of setting（Threshold values by transistor Q3 blanking voltage and resistance R7
Resistance determines）When, when feeding back to transistor Q3 voltage and being more than cutoff, transistor Q3 conductings, after " reference voltage " is dragged down,
Transistor Q4, Q5 ... Qn end.Because transistor Q4 ends, transistor Q3 base stages are dragged down by resistance R7, transistor Q3 cut-offs.
" reference voltage " obtains high level again.So repeatedly.By the above-mentioned course of work, in the case of no electric capacity C1,
The slight scintillation for the moment that is powered occurs in LED, and an electric capacity C1 is put between transistor Q3 base stage and colelctor electrode, can
To improve in the glittering phenomenon of moment that is powered so that constant current output control is more stable.
Structure in the utility model and without using constant pressure IC or constant current IC, therefore can effectively reduce development cost；
It is good to Electro Magnetic Compatibility without these circuits external conducted emission and radiation-emitting；Remain dimming portion simultaneously.This practicality
Constant current structure in new, to constant current source structure, on the basis of image reference constant-current source, makes other branch roads have identical using mirror
Electric current, it ensure that the stability of each branch road output.Therefore, the utility model is realized more safe and reliable with relatively low cost
Purpose.
Above example only to illustrate the technical solution of the utility model and unrestricted, those of ordinary skill in the art couple
Other modifications or equivalent substitution that the technical solution of the utility model is made, without departing from technical solutions of the utility model
Spirit and scope, it all should cover in right of the present utility model.
Claims (5)
- A kind of 1. inexpensive current constant control lighting circuit, it is characterised in that：Including adjusting control circuit, the ratio being sequentially connected electrically Compared with circuit, mirror-image constant flow source, LED and current-limiting resistance；The comparison circuit includes transistor Q3, resistance R5 and R6, resistance R5 mono- The output end of end connection adjusting control circuit, the other end connect resistance R6 and transistor Q3 colelctor electrode respectively, and resistance R6's is another One end and transistor Q3 grounded emitter；The mirror-image constant flow source includes transistor Q4 and resistance R7, transistor Q4 collection Electrode is connected with LED negative electrode, transistor Q4 emitter stage connection resistance R7, resistance R7 other ends ground connection, transistor Q4 base Pole is connected with transistor Q3 colelctor electrode, LED anode connection current-limiting resistance；Transistor Q4 base stage and transistor Q3 base stage Between be connected with electric capacity C1.
- A kind of 2. inexpensive current constant control lighting circuit according to claim 1, it is characterised in that：The comparison circuit And the transistor arrived used in mirror-image constant flow source uses NPN transistor.
- A kind of 3. inexpensive current constant control lighting circuit according to claim 1, it is characterised in that：The mirror image constant current Source, LED and current-limiting resistance form illumination output circuit, and the illumination output circuit sets one group.
- A kind of 4. inexpensive current constant control lighting circuit according to claim 1, it is characterised in that：The mirror image constant current Source, LED and current-limiting resistance form illumination output circuit, and illumination output circuit setting is multigroup, is joined directly together with comparison circuit First group is image reference constant-current source, and other every group formed in parallel with first group illuminates output branch circuit, and per component Base stage of the transistor base of mirror-image constant flow source with transistor in first group of image reference constant-current source is connected in branch circuit.
- A kind of 5. inexpensive current constant control lighting circuit according to claim 1, it is characterised in that：The brightness adjustment control Circuit includes NPN transistor Q1, PNP transistor Q2, resistance R1 to R4, resistance R1 and resistance R2 series connection, the resistance R1 other end Connect power supply and transistor Q1 emitter stage, resistance R2 other end connection transistor Q2 colelctor electrode, the connection of resistance R3 one end Illumination driving Enable Pin, other end connection transistor Q2 base stage, resistance R4 one end connection transistor Q2 base stage, another termination Ground, transistor Q2 grounded emitter, transistor Q1 colelctor electrode are connected with resistance R5.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720567567.6U CN206894949U (en) | 2017-05-22 | 2017-05-22 | A kind of inexpensive current constant control lighting circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720567567.6U CN206894949U (en) | 2017-05-22 | 2017-05-22 | A kind of inexpensive current constant control lighting circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN206894949U true CN206894949U (en) | 2018-01-16 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201720567567.6U Expired - Fee Related CN206894949U (en) | 2017-05-22 | 2017-05-22 | A kind of inexpensive current constant control lighting circuit |
Country Status (1)
| Country | Link |
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| CN (1) | CN206894949U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115134963A (en) * | 2022-06-28 | 2022-09-30 | 无锡市益明光电有限公司 | Prevent regulating circuit of LED lamp low temperature scintillation |
-
2017
- 2017-05-22 CN CN201720567567.6U patent/CN206894949U/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115134963A (en) * | 2022-06-28 | 2022-09-30 | 无锡市益明光电有限公司 | Prevent regulating circuit of LED lamp low temperature scintillation |
| CN115134963B (en) * | 2022-06-28 | 2023-04-14 | 无锡市益明光电有限公司 | Prevent regulating circuit of LED lamp low temperature scintillation |
| US11792902B1 (en) | 2022-06-28 | 2023-10-17 | Wuxi Seastar Lighting Co., Ltd. | Regulating circuit capable of preventing low-temperature flickering of LED lamp |
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| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20180116 |
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| CF01 | Termination of patent right due to non-payment of annual fee |