CN201528453U - LED constant current source capable of half-power controlling - Google Patents
LED constant current source capable of half-power controlling Download PDFInfo
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- CN201528453U CN201528453U CN2009202482766U CN200920248276U CN201528453U CN 201528453 U CN201528453 U CN 201528453U CN 2009202482766 U CN2009202482766 U CN 2009202482766U CN 200920248276 U CN200920248276 U CN 200920248276U CN 201528453 U CN201528453 U CN 201528453U
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Abstract
The utility model relates to an LED constant current source capable of half-power controlling, which fundamentally resolves problems of short service life, incapability of realizing half-power light adjusting control, excessively high cost of peripheral circuits and relatively large power consumption of a constant current source of existing LED lighting. A power circuit provides stable 12v voltage to a DC/DC converting power circuit and a half-power circuit, the DC/DC converting power circuit comprises a DC/DC converting power supply chip U1, PWM signals providing constant frequency to a booster circuit, and a feedback circuit providing current feedback and voltage feedback to the DC/DC converting power circuit, the DC/DC converting power circuit adjusts duty ratio of the output signals PWM according to feedback values, automatic adjusting feedback process leads voltage and current at an adjusted end to remain unchanged, and the half-power circuit affects reference voltage by the on-offs of an optical coupler U2. An LED light source adopting the LED constant current source capable of half-power controlling has the advantages of long service life, low cost, and capability of realizing half-power light adjusting control, energy conservation, wide application range and the like.
Description
Technical field
But the utility model relates to the LED illumination constant-current source of the half-power control of a kind of high efficiency, high input voltage, belongs to the stabilized current power supply technical field.Be applicable to prolong the LED lighting source the low-cost occasion that realizes that the half-power brightness adjustment control requires.
Background technology
At actual needs with in using; though a lot of load power consumptions are little; but the source current, the voltage that require to be provided must keep relative stability within the specific limits; requiring simultaneously has the certain protection effect to the subelement in the load; constant current or stabilized voltage power supply are normally adopted in the power supply that solves this class load; and in power circuit, also need to add to the circuit overcurrent protection of some element under abnormal conditions in the load, this just makes that this class power supply is that element is many, circuit is complicated, the power consumption ratio is big mostly.At present, the application of LED more and more widely, it is also just more and more universal to be used for daily indoor and LED light fixture outdoor lighting, but can't realize low-cost half-power control.Though the illumination of present LED stability better, luminosity changes little, and the life-span of throwing light on is short, and its peripheral peripheral circuit cost is too high.In addition, its power that consumes on peripheral circuit is big with respect to the power consumed ratio of LED own, usually be loss power account for whole power 20%～30%, the advantage of the energy-conservation province consumption of LED is not brought into play fully.So existing LED constant-current source circuit is still waiting to improve.
The utility model content
But the purpose of this utility model provides the LED constant-current source of the half-power control of a kind of high efficiency, high input voltage, fundamentally solve existing LED illumination life-span weak point, can't realize low-cost half-power control, problems such as constant-current source circuit periphery peripheral circuit cost is too high, loss power is bigger, to led light source have long-life, low cost, can realize the half-power brightness adjustment control, energy-conservation, advantage such as the scope of application is wide.
The technical solution of the utility model is: but the LED constant-current source of this half-power control comprises power circuit, DC/DC converting power source circuit, booster circuit, feedback circuit and half-power circuit, its technical essential is: described power circuit provides stable 12v voltage to DC/DC converting power source circuit and half-power circuit, described DC/DC converting power source circuit comprises DC/DC converting power source chip U, the pwm signal of a fixed frequency is provided for described booster circuit, described feedback circuit provides feedback for described DC/DC converting power source circuit, be respectively current feedback and Voltage Feedback, described DC/DC converting power source circuit is adjusted the duty ratio of output signal PWM according to the situation of value of feedback, automatically adjust feedback procedure and make the adjustment terminal voltage, electric current remains unchanged, described half-power circuit influences reference voltage by the break-make of optocoupler U2, thereby the change load current, the size of described load current is by the size decision of the 15 pin institute connecting resistance of DC/DC converting power source chip U1.
1 pin of the DC/DC converting power source chip U1 of described DC/DC converting power source circuit connects sampled voltage, and 2 pin connect the 5v reference voltage, and 16 pin connect sample rate current, and 15 pin connect current reference.1 pin output pwm signal, and by two triodes raising driving forces, 10 pin are unsettled, 2 pin, 13 pin, 14 pin connect together, and 11 pin, 12 pin, 8 pin connect 12v voltage.
Current sample sampling resistor R24 crossfire high-power by, low resistance is realized at load end in the described feedback circuit.
Described half-power circuit control realizes by the break-make of optocoupler U2, changes the size of divider resistance value, to change the size of load current.
Input voltage 48v reduces to 12v by voltage stabilizing didoe in the described power circuit, is circuit supply.
Described booster circuit charges storage capacitor by the break-make of metal-oxide-semiconductor repeatedly, to improve load voltage, wherein comprises Schottky diode.
Advantage of the present utility model and positive technique effect are: the utility model is by high-frequency impulse bandwidth modulation signals PWM control DC/DC inverter tube MOS, and direct current is added in the load; Output feeds back to control circuit by certain circuit, and control PWM duty ratio is to reach the purpose of stable output; Break-make by the control optocoupler realizes half-power; The efficient height, wide input voltage range.To sum up, the utility model utilizes adjustable DC output DC/DC converting power source to be electric, by the high and low convenient variation that realizes full half-power of the level of half-power control end.By the electromagnetic induction booster tension, realize high efficiency, high-performance, wide input voltage.The two-way feedback circuit is realized constant voltage, constant current control, to led light source have long-life, low cost, can realize the half-power brightness adjustment control, energy-conservation, advantage such as the scope of application is wide.Problems such as it is short fundamentally to have solved the existing LED illumination life-span, can't realize low-cost half-power control, and constant-current source circuit periphery peripheral circuit cost is too high, loss power is bigger.
Description of drawings
The utility model is described in further detail below in conjunction with accompanying drawing.
Fig. 1 is circuit theory diagrams of the present utility model.
Embodiment
According to Fig. 1 concrete structure of the present utility model is described in detail.But the LED constant-current source that is somebody's turn to do half-power control comprises power circuit, DC/DC converting power source circuit, booster circuit, feedback circuit and half-power circuit.Power circuit provides stable 12v voltage to DC/DC converting power source circuit and half-power circuit, and DC/DC converting power source circuit comprises DC/DC converting power source chip U1 (present embodiment adopts TL494), and the pwm signal of a fixed frequency is provided for booster circuit.Metal-oxide-semiconductor of output control by adjustable DC output DC/DC converting power source circuit, for load circuit provides power supply, the output of the one termination adjustable DC output DC/DC converting power source circuit of load circuit, the return terminal of another termination adjustable DC output DC/DC converting power source circuit of load circuit, i.e. ground terminal.Feedback circuit is respectively a current feedback for DC/DC converting power source circuit provides feedback, a Voltage Feedback.DC/DC converting power source circuit is according to the duty ratio of the situation adjustment output signal PWM of value of feedback, and it adjusts feedback procedure automatically remains unchanged adjustment terminal voltage, electric current.The half-power circuit influences reference voltage by the break-make of optocoupler U2, thereby changes load current, and the size of load current is by the size decision of the 15 pin institute connecting resistance of DC/DC converting power source chip U1.1 pin of the DC/DC converting power source chip U1 of DC/DC converting power source circuit connects sampled voltage, and 2 pin connect the 5v reference voltage, and 16 pin connect sample rate current, and 15 pin connect current reference.1 pin output pwm signal, and by two triodes raising driving forces, 10 pin are unsettled, 2 pin, 13 pin, 14 pin connect together, and 11 pin, 12 pin, 8 pin connect 12v voltage.
As shown in Figure 1, specified input voltage is 48v in the power circuit, after voltage stabilizing is handled through voltage stabilizing didoe (present embodiment adopts LN4742), stable 12v voltage is provided for DC/DC converting power source chip and other control circuits.Booster circuit is by the break-make of metal-oxide-semiconductor Q4, storage capacitor is charged repeatedly, directly be added in load end behind input voltage process energy storage inductor L1 and the Schottky diode Q5 (present embodiment adopts SR2080), DC/DC converting power source chip U1 exports the pwm signal of an EDM Generator of Adjustable Duty Ratio simultaneously, and the break-make of control Q4 can improve the voltage with the steady load two ends.One road feedback circuit is that sampling resistor R24 high-power by, low resistance is connected on the load current of sampling in the load in the feedback circuit, feeds back to DC/DC converting power source chip U1; Another road feedback circuit is by R6, R12, C9, the R11 load voltage of sampling, and also feeds back to DC/DC converting power source chip U1, and the duty ratio of the pwm signal of U1 output is regulated in effect simultaneously, with electric current, the voltage of steady load.Optocoupler U2 (present embodiment adopt PC817), resistance R 2 and variable resistor R9, resistance R 10 parallel connections are added in 15 ends of DC/DC converting power source chip U1 then with after resistance R 13 dividing potential drops, and reference voltage is provided.Power circuit control changes the size of divider resistance value by the break-make of optocoupler U2, thereby changes the size of load current.
Below the various piece circuit is described in detail.
Power circuit mainly is made up of resettable fuse F1, filter capacitor C1, diode D1, current-limiting resistance R25, divider resistance R26, voltage stabilizing didoe D4.When circuit short circuit or electric current occur when excessive, the F1 automatic disconnection is with protective circuit; D1 works as power positive cathode and connects the inverse time protective circuit; The stable output of D4 12v voltage.
DC/DC converting power source circuit mainly is made up of DC/DC converting power source chip U1 and peripheral components, triode Q2, Q3 etc.The U1 input voltage is 12v, and pwm signal of U1.9 end output amplifies by Q2, Q3, is connected on the grid of metal-oxide-semiconductor Q4.There are two groups of independently computing amplifying units U1 inside, and U1.1, U1.2 and U1.16, U1.15 are respectively the inputs of two groups of amplifiers, and the output acting in conjunction of amplifier influences the duty ratio of PWM output signal.R14 and C6 form vibration in conjunction with the U1 internal circuit and produce circuit, and its frequency of oscillation is f=1.1/R14*C6.U1 inside provides 5v reference voltage, is exported by U1.14.
Booster circuit is made up of metal-oxide-semiconductor Q4, energy storage inductor L1, Schottky diode Q5, storage capacitor C3, filter capacitor C4.When the Q4 grid connects high level, the Q4 conducting, VCC forms the loop by L1 and Q4, and electric current only flows to Q4; When the Q4 grid connect low level, Q4 disconnected, and L1 produces inverse electromotive force by electromagnetic induction, charge to C3 with the VCC Q5 that is superimposed, and powering load; As Q4 once more during conducting, stored electric energy among the C3, continue powering load, simultaneously Q5 resistance reverse direction current flow; When Q4 disconnects once more, C3 is recharged once more, and its both end voltage is that load voltage is more and more higher, to satisfy the load needs.The duty specific energy of pwm signal is controlled the time scale of Q4 break-make, thereby influences the voltage and current of load.
Feedback circuit comprises the two-way feedback.One route R6, R12, C9, R11 form, and gather the positive input U1.1 that load voltage offers the inner amplifier of U1 unit, and reverse input end U1.2 connects the 5v reference voltage, the duty ratio of the variable effect PWM of sampled voltage, thereby the variation of inhibition load voltage.Another road feedback circuit is made up of R24, R19, and R24 connects with load and gathers load current, offers U1.16, and U1.15 connects a reference voltage, is obtained by R13, R16, R5, R17, U2, R9, R10 dividing potential drop.This road feedback is equally by regulating the variation that duty recently suppresses load current.U1.15 holds to such an extent that reference voltage has determined the size of load current.
The half-power circuit mainly is made up of triode Q1, optocoupler U2, variable resistor R9.When K holds when unsettled, the Q1 base stage is a high level, the Q1 conducting, and the U2 conducting, the voltage of U1.15 end is by obtaining by R7 and U2 dividing potential drop, and partial pressure value is low, so load current is little, is the half-power state; When K end ground connection, U2 disconnects, and electric current flows through R9 and R10, the partial pressure value height, and load current is big, is full power state.
In the foregoing circuit, except that having illustrated, all elements there is not specific (special) requirements.Related element can adopt other similar products among the embodiment.
Claims (6)
1. but the LED constant-current source of half-power control, comprise power circuit, DC/DC converting power source circuit, booster circuit, feedback circuit and half-power circuit, it is characterized in that: described power circuit provides stable 12v voltage to DC/DC converting power source circuit and half-power circuit, described DC/DC converting power source circuit comprises DC/DC converting power source chip U1, the pwm signal of a fixed frequency is provided for described booster circuit, described feedback circuit provides feedback for described DC/DC converting power source circuit, be respectively current feedback and Voltage Feedback, described DC/DC converting power source circuit is adjusted the duty ratio of output signal PWM according to the situation of value of feedback, automatically adjust feedback procedure and make the adjustment terminal voltage, electric current remains unchanged, described half-power circuit influences reference voltage by the break-make of optocoupler U2, thereby the change load current, the size of described load current is by the size decision of the 15 pin institute connecting resistance of DC/DC converting power source chip U1.
2. but the LED constant-current source of half-power control according to claim 1, it is characterized in that: 1 pin of the DC/DC converting power source chip U1 of described DC/DC converting power source circuit connects sampled voltage, 2 pin connect the 5v reference voltage, and 16 pin connect sample rate current, and 15 pin connect current reference.1 pin output pwm signal, and by two triodes raising driving forces, 10 pin are unsettled, 2 pin, 13 pin, 14 pin connect together, and 11 pin, 12 pin, 8 pin connect 12v voltage.
3. but the LED constant-current source of half-power control according to claim 1, it is characterized in that: current sample sampling resistor R24 crossfire high-power by, low resistance is realized at load end in the described feedback circuit.
4. but the LED constant-current source of half-power control according to claim 1 is characterized in that: described half-power circuit control realizes by the break-make of optocoupler U2, changes the size of divider resistance value, to change the size of load current.
5. but the LED constant-current source of half-power control according to claim 1, it is characterized in that: input voltage 48v reduces to 12v by voltage stabilizing didoe in the described power circuit, is circuit supply.
6. but the LED constant-current source of half-power control according to claim 1, it is characterized in that: described booster circuit charges storage capacitor by the break-make of metal-oxide-semiconductor repeatedly, to improve load voltage, wherein comprises Schottky diode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009202482766U CN201528453U (en) | 2009-11-20 | 2009-11-20 | LED constant current source capable of half-power controlling |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009202482766U CN201528453U (en) | 2009-11-20 | 2009-11-20 | LED constant current source capable of half-power controlling |
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| CN201528453U true CN201528453U (en) | 2010-07-14 |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101925230A (en) * | 2010-07-29 | 2010-12-22 | 福建捷联电子有限公司 | LED (Light Emitting Diode) drive power source with high efficiency, low power consumption and low cost |
| CN102685966A (en) * | 2011-03-10 | 2012-09-19 | 海洋王照明科技股份有限公司 | Constant current circuit and lamp |
| CN104219819A (en) * | 2013-05-30 | 2014-12-17 | 深圳市海洋王照明工程有限公司 | Dimming circuit and lamp thereof |
| CN106092164A (en) * | 2016-08-29 | 2016-11-09 | 刘洲 | A kind of device of virtual display composition of air |
| WO2020077553A1 (en) * | 2018-10-17 | 2020-04-23 | Texas Instruments Incorporated | A voltage regulator with an adaptive off-time generator |
-
2009
- 2009-11-20 CN CN2009202482766U patent/CN201528453U/en not_active Expired - Fee Related
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101925230A (en) * | 2010-07-29 | 2010-12-22 | 福建捷联电子有限公司 | LED (Light Emitting Diode) drive power source with high efficiency, low power consumption and low cost |
| CN101925230B (en) * | 2010-07-29 | 2012-12-26 | 福建捷联电子有限公司 | LED (Light Emitting Diode) drive power source with high efficiency, low power consumption and low cost |
| CN102685966A (en) * | 2011-03-10 | 2012-09-19 | 海洋王照明科技股份有限公司 | Constant current circuit and lamp |
| CN102685966B (en) * | 2011-03-10 | 2015-10-28 | 海洋王照明科技股份有限公司 | A kind of constant-current circuit and light fixture |
| CN104219819A (en) * | 2013-05-30 | 2014-12-17 | 深圳市海洋王照明工程有限公司 | Dimming circuit and lamp thereof |
| CN104219819B (en) * | 2013-05-30 | 2016-12-28 | 深圳市海洋王照明工程有限公司 | Light adjusting circuit and light fixture thereof |
| CN106092164A (en) * | 2016-08-29 | 2016-11-09 | 刘洲 | A kind of device of virtual display composition of air |
| WO2020077553A1 (en) * | 2018-10-17 | 2020-04-23 | Texas Instruments Incorporated | A voltage regulator with an adaptive off-time generator |
| US10826392B2 (en) | 2018-10-17 | 2020-11-03 | Texas Instruments Incorporated | Voltage regulator with an adaptive off-time generator |
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Legal Events
| Date | Code | Title | Description |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20100714 Termination date: 20131120 |