CN202121822U - Led constant current drive circuit - Google Patents
Led constant current drive circuit Download PDFInfo
- Publication number
- CN202121822U CN202121822U CN2011201549770U CN201120154977U CN202121822U CN 202121822 U CN202121822 U CN 202121822U CN 2011201549770 U CN2011201549770 U CN 2011201549770U CN 201120154977 U CN201120154977 U CN 201120154977U CN 202121822 U CN202121822 U CN 202121822U
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- drive circuit
- comparator
- led
- current
- timer
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
- Y02B20/40—Control techniques providing energy savings, e.g. smart controller or presence detection
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- Circuit Arrangement For Electric Light Sources In General (AREA)
Abstract
The utility model relates to an LED constant current drive circuit, comprising a comparator used for comparing a reference voltage and a sampling voltage of LED drive current; a timer used for emitting a corresponding PWM signal according to a comparing result of the comparator; and a drive circuit used for carrying out LED drive according to the PWM signal. One input terminal of the comparator is connected with the drive circuit through a sampling circuit; the other input terminal of the comparator inputs the reference voltage; an output terminal of the comparator is connected with the timer; and the timer is connected with the drive circuit. The LED constant current drive circuit is completed based on a programmable device; the structure is simple; the application is flexible; functions are complete; especially the price cost has great advantage; and the defects of complex structure, many components, high cost and low reliability of the LED constant current drive circuit of the prior arts are avoided.
Description
Technical field
The utility model relates to circuit control field, more particularly, relates to a kind of LED constant-current drive circuit based on programming device.
Background technology
The LED illumination has obtained global concern as a kind of brand-new lighting technology, is described as the revolution for the third time on the human illumination history.Compare with traditional relatively halogen low-voltage lighting; Adopt high-brightness LED to have a lot of benefits as room lighting, street lighting, Landscape Lighting, vehicle-mounted illumination; High-brightness LED can provide bigger brightness with littler power consumption, the characteristics that have energy-saving and environmental protection, antidetonation, long service life and connect fast.Particularly along with China's rapid economy development; Energy problem more and more causes people's attention; Energy-saving and emission-reduction have become a great strategic problem of current China, LED illumination with its remarkable energy conservation characteristic at lighting field in occupation of important position more and more.
LED is the driving device of a typical current, and high precisely control LED drive current can determine to comprise many parameters of optical efficiency, power-efficient, heat radiation and product brightness etc.Driving LED mainly is to control its electric current.As shown in Figure 1, after the complete conducting of LED, minimum voltage fluctuation all can cause the variation that electric current is very big, directly influences the parameter indexs such as brightness, heat radiation and useful life of lamp, so the constant current of LED control is extremely important for the use of LED.
Present LED constant-current driving power supply adopts the application-specific integrated circuit (ASIC) scheme to accomplish more; Exist circuit structure complicacy, components and parts are many, cost is high, reliability is low shortcoming; Particularly there is huge inferior position in Costco Wholesale and aspect of performance; And application-specific integrated circuit (ASIC) design function expansibility is poor, is difficult to satisfy the flexile demand of LED power supply.
The utility model content
The technical problem that the utility model will solve is; To the LED constant-current drive circuit complex structure of prior art, the defective that components and parts are many, cost is high and reliability is low; Provide a kind of, particularly on Costco Wholesale, occupy the LED constant-current drive circuit of very big advantage based on programming device completion, simple in structure, applying flexible, multiple functional.
The utility model solves the technical scheme that its technical problem adopted: construct a kind of LED constant-current drive circuit, comprising: the comparator that is used for the sampled voltage of comparison reference voltage and LED drive current; Be used for sending the timer of corresponding pwm signal according to the comparative result of said comparator; And be used for carrying out the drive circuit that LED drives according to said pwm signal; An input of said comparator is connected with said drive circuit through sample circuit, and another input of said comparator is imported said reference voltage, and the output of said comparator is connected with said timer; Said timer is connected with said drive circuit.
In the described LED constant-current drive circuit of the utility model; Based on said comparator output and said timer output interlock function; The positive input of said comparator is imported the sampled voltage of said LED drive current, and the reverse input end of said comparator is imported said reference voltage.
In the described LED constant-current drive circuit of the utility model; Said LED constant-current drive circuit also comprises light-adjusting module; Said light-adjusting module comprises the selected cell that is used for that the register of said reference voltage is set and is used to select the corresponding reference voltage of said register; Said register is connected with said comparator, and said selected cell is connected with said register.
In the described LED constant-current drive circuit of the utility model, said selected cell is the infrared remote control control panel, said infrared remote control control panel and said register wireless connections.
In the described LED constant-current drive circuit of the utility model, said drive circuit comprises and being used for according to the switch element of said pwm signal control LED constant-current drive circuit break-make and the driver element that boosts that is used for LED is carried out constant-current driving.
In the described LED constant-current drive circuit of the utility model; Said switch element comprises FET and FET drive circuit; The input of said FET is connected with power input through power inductance; The output head grounding of said FET, the control end of said FET is connected with said timer through said FET drive circuit.
Implement the LED constant-current drive circuit of the utility model; Has following beneficial effect: based on programming device completion, simple in structure, applying flexible, multiple functional; Particularly on Costco Wholesale, occupy great advantage, avoided the LED constant-current drive circuit complex structure of prior art, the defective that components and parts are many, cost is high and reliability is low.
Description of drawings
To combine accompanying drawing and embodiment that the utility model is described further below, in the accompanying drawing:
Fig. 1 is the electric current of the LED after the complete conducting of the LED of prior art and the graph of a relation of voltage;
Fig. 2 is the structural representation of first preferred embodiment of the LED constant-current drive circuit of the utility model;
Fig. 3 is the structural representation of second preferred embodiment of the LED constant-current drive circuit of the utility model;
Fig. 4 is the structural representation of the 3rd preferred embodiment of the LED constant-current drive circuit of the utility model;
Fig. 5 is the particular circuit configurations figure of preferred embodiment of the LED constant-current drive circuit of the utility model.
Embodiment
For the purpose, technical scheme and the advantage that make the utility model is clearer,, the utility model is further elaborated below in conjunction with accompanying drawing and embodiment.Should be appreciated that specific embodiment described herein only in order to explanation the utility model, and be not used in qualification the utility model.
In the structural representation of first preferred embodiment of the LED of the utility model shown in Figure 2 constant-current drive circuit; Said LED constant-current drive circuit comprises comparator 1, timer 2 and drive circuit 3; Comparator 1 is used for the sampled voltage of comparison reference voltage and LED drive current; Timer 2 is used for sending corresponding pwm signal according to the comparative result of said comparator 1, and drive circuit 3 is used for carrying out LED according to said pwm signal and drives.An input of said comparator 1 is connected with said drive circuit 3 through sample circuit, and another input of said comparator 1 is imported said reference voltage, and the output of said comparator 1 is connected with said timer 2; Said timer 2 is connected with said drive circuit 3.
When the LED constant-current drive circuit of the utility model uses; The user sets reference voltage, the sampled voltage of the LED drive current of sampling then, comparator 1 comparison reference voltage and sampled voltage according to drive current earlier; Like sampled voltage greater than reference voltage; Explain that then the LED drive current is bigger, device 2 when comparator 1 will send corresponding signal feeding makes timer 2 send corresponding pwm signal to reduce the LED drive current of drive circuit 3; Less than reference voltage, explain then that the LED drive current is less like sampled voltage, device 2 when comparator 1 will send corresponding signal feeding makes timer 2 send corresponding pwm signal to increase the LED drive current of drive circuit 3.The LED constant-current drive circuit of the utility model makes the electric current on the LED reach preset steady state value through the duty ratio of the Switching Power Supply control signal of variation control timer 2 outputs of monitoring LED drive current.The LED constant-current drive circuit of the utility model is based on the Programmable Logic Controller of single write-in program; Add simple external component; Can realize the function that high precision constant current drives; Can flexible Application in several watts to tens watts different power ranks, the LED constant-current drive circuit functions expanding of the utility model is easy in addition, can satisfy diversified demand.
Preferred embodiment as the LED constant-current drive circuit of the utility model; Based on said comparator 1 output and said timer 2 output interlock function; The positive input of said comparator 1 is imported the sampled voltage of said LED drive current; The reverse input end of said comparator 1 is imported said reference voltage, and when said comparator 1 sent high level, said timer 2 resetted pwm signal to reduce the duty ratio of said pwm signal; When said comparator 1 sent low level, said timer 2 was restarted to increase the duty ratio of said pwm signal.
Carry out corresponding two kinds of operations because the LED constant-current drive circuit of the utility model is merely able to receive two kinds of signals of comparator 1, thus timer 2 produce reset pwm signal with restart two kinds of actions of timer 2.Simultaneously owing to have only two actions, so the pwm signal duty ratio that timer 2 begins to send is bigger, to give timer 2 sufficient adjustment space.When sampled voltage during less than reference voltage, explain that then the LED drive current is less, at this moment timer 2 resets, and partly restarts to make the duty ratio of pwm signal to increase to increase the LED drive current from the high level of pwm signal; When sampled voltage during greater than reference voltage, explain that then the LED drive current is bigger, at this moment the timer 2 pwm signal (even pwm signal forwards low level to) that resets reduces to reduce the LED drive current duty ratio of pwm signal; Like this through constantly reset pwm signal with restart timer 2 the duty ratio of pwm signal adjusted.Comparator 1 can connect method accordingly according to user's custom use can reach same technique effect.
In the structural representation of second preferred embodiment of the LED of the utility model shown in Figure 3 constant-current drive circuit; Said LED constant-current drive circuit comprises light-adjusting module 4; Light-adjusting module 4 comprises register 41 and selected cell 42, and register 41 is used to be provided with said reference voltage, and selected cell 42 is used for selecting said register 41 corresponding reference voltages; Said register 41 is connected with said comparator 1, and said selected cell 42 is connected with said register 41.Said selected cell 42 is the infrared remote control control panel, said infrared remote control control panel and 41 wireless connections of said register.
The numerical value of reference voltage can be provided with through register 41 flexibly in the light-adjusting module 4 of the utility model; Have 32 ranks in the present embodiment; We select through the reference voltage in 42 pairs of relevant registers 41 of selected cell; Thereby the dimming function that realization light modulation, the utility model realize response is fast, flicker free, all keep the delivery efficiency more than 90% at each gray scale power supply changeover device.As adopt the infrared remote control control panel can the visual easily selection of carrying out reference voltage as 42 users of selected cell.
In the structural representation of the 3rd preferred embodiment of the LED of the utility model shown in Figure 4 constant-current drive circuit; Said drive circuit 3 comprises switch element 31 and the driver element 32 that boosts; Switch element 31 is used for according to said pwm signal control LED constant-current drive circuit break-make, and the driver element 32 that boosts is used for LED is carried out constant-current driving.Said switch element 31 comprises FET and FET drive circuit; The input of said FET is connected with power input through power inductance; The output head grounding of said FET, the control end of said FET is connected with said timer 2 through said FET drive circuit.
As shown in Figure 5, adopt FET to carry out the management of LED constant-current drive circuit break-make, reaction is quick, and when pwm signal was its high level section, FET was connected, and input voltage stores the energy in the inductance; When pwm signal is its low level section; FET breaks off; Energy in the inductance obtains discharging and is used for driving LED, and the control through switch element 31 can well convert pwm signal into to LED constant current control, thereby realizes accurate LED constant-current driving control.
As the preferred embodiment of the LED constant-current drive circuit of the utility model, the output voltage U of the said driver element 32 that boosts
OutWith input voltage U
InBetween relation be:
Wherein D is the duty ratio of said pwm signal.
The LED constant-current drive circuit of the utility model adopts BOOST (boosting) power supply topologies, relation below its output voltage and input voltage exist:
Wherein D is the duty ratio of pwm signal, and the size of D has directly determined output voltage values.The LED constant-current drive circuit of the utility model has utilized the interlock function of timer 2 and comparator 1; Be that timer 2 can reset during for significant level at comparator 1, reduce the value of duty ratio, equate with reference voltage up to the sampled voltage of LED drive current; Because this part of functions is to be accomplished by analog circuit; So the time output summary responses of realizing input voltage fluctuation, particularly change the situation that lamp can not occur glimmering when big, and keep power utilization efficient up to more than 90% in fluctuation.
The above is merely the embodiment of the utility model; Be not thus the restriction the utility model claim; Every equivalent structure transformation that utilizes the utility model specification and accompanying drawing content to be done; Or directly or indirectly be used in other relevant technical fields, all in like manner be included in the scope of patent protection of the utility model.
Claims (6)
1. a LED constant-current drive circuit is characterized in that, comprising:
The comparator (1) that is used for the sampled voltage of comparison reference voltage and LED drive current;
Be used for sending the timer (2) of corresponding pwm signal according to the comparative result of said comparator (1); And
Be used for carrying out the drive circuit (3) that LED drives according to said pwm signal;
An input of said comparator (1) is connected with said drive circuit (3) through sample circuit, and another input of said comparator (1) is imported said reference voltage, and the output of said comparator (1) is connected with said timer (2); Said timer (2) is connected with said drive circuit (3).
2. LED constant-current drive circuit according to claim 1; It is characterized in that; Based on said comparator (1) output and said timer (2) output interlock function; The positive input of said comparator (1) is imported the sampled voltage of said LED drive current, and the reverse input end of said comparator (1) is imported said reference voltage.
3. LED constant-current drive circuit according to claim 1; It is characterized in that; Said LED constant-current drive circuit also comprises light-adjusting module (4); The selected cell (42) that said light-adjusting module (4) comprises the register (41) that is used for being provided with said reference voltage and is used to select the corresponding reference voltage of said register (41), said register (41) is connected with said comparator (1), and said selected cell (42) is connected with said register (41).
4. LED constant-current drive circuit according to claim 3 is characterized in that, said selected cell (42) is the infrared remote control control panel, said infrared remote control control panel and said register (41) wireless connections.
5. LED constant-current drive circuit according to claim 1; It is characterized in that said drive circuit (3) comprises and being used for according to the switch element (31) of said pwm signal control LED constant-current drive circuit break-make and the driver element that boosts (32) that is used for LED is carried out constant-current driving.
6. LED constant-current drive circuit according to claim 5; It is characterized in that; Said switch element (31) comprises FET and FET drive circuit; The input of said FET is connected with power input through power inductance, the output head grounding of said FET, and the control end of said FET is connected with said timer (2) through said FET drive circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011201549770U CN202121822U (en) | 2011-05-16 | 2011-05-16 | Led constant current drive circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011201549770U CN202121822U (en) | 2011-05-16 | 2011-05-16 | Led constant current drive circuit |
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| Publication Number | Publication Date |
|---|---|
| CN202121822U true CN202121822U (en) | 2012-01-18 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011201549770U Expired - Fee Related CN202121822U (en) | 2011-05-16 | 2011-05-16 | Led constant current drive circuit |
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| CN (1) | CN202121822U (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102664524A (en) * | 2012-05-09 | 2012-09-12 | 无锡创想华微科技有限公司 | Constant current DC (Direct Current)-DC converter utilizing digital PWM (Pulse-Width Modulation) control and constant current LED (Light Emitting Diode) drive DC-DC converter |
| CN102737583A (en) * | 2012-07-09 | 2012-10-17 | 深圳市磊芯半导体有限公司 | LED (Light Emitting Diode) driving constant current channel output driver, cascading system and driving method of LED driving constant current channel output driver and cascading system |
| CN103118467A (en) * | 2013-02-18 | 2013-05-22 | 盐城工学院 | High-power LED constant current driving circuit and parameter algorithm thereof |
| CN105212272A (en) * | 2015-09-16 | 2016-01-06 | 西安拓尔微电子有限责任公司 | A kind of constant voltage exports electronic cigarette and electronic cigarette chip |
| CN109496006A (en) * | 2017-09-12 | 2019-03-19 | 上海产业技术研究院 | A kind of LED constant current control system and method accurately dimmed |
| CN111276093A (en) * | 2020-03-19 | 2020-06-12 | 季春 | Low-cost drive circuit of programming device VPP high-voltage circuit |
-
2011
- 2011-05-16 CN CN2011201549770U patent/CN202121822U/en not_active Expired - Fee Related
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102664524A (en) * | 2012-05-09 | 2012-09-12 | 无锡创想华微科技有限公司 | Constant current DC (Direct Current)-DC converter utilizing digital PWM (Pulse-Width Modulation) control and constant current LED (Light Emitting Diode) drive DC-DC converter |
| CN102737583A (en) * | 2012-07-09 | 2012-10-17 | 深圳市磊芯半导体有限公司 | LED (Light Emitting Diode) driving constant current channel output driver, cascading system and driving method of LED driving constant current channel output driver and cascading system |
| CN102737583B (en) * | 2012-07-09 | 2015-06-17 | 深圳市磊芯半导体有限公司 | LED (Light Emitting Diode) driving constant current channel output driver, cascading system and driving method of LED driving constant current channel output driver and cascading system |
| CN103118467A (en) * | 2013-02-18 | 2013-05-22 | 盐城工学院 | High-power LED constant current driving circuit and parameter algorithm thereof |
| CN103118467B (en) * | 2013-02-18 | 2015-10-14 | 盐城工学院 | A kind of high power LED constant-current driving circuit |
| CN105212272A (en) * | 2015-09-16 | 2016-01-06 | 西安拓尔微电子有限责任公司 | A kind of constant voltage exports electronic cigarette and electronic cigarette chip |
| CN109496006A (en) * | 2017-09-12 | 2019-03-19 | 上海产业技术研究院 | A kind of LED constant current control system and method accurately dimmed |
| CN111276093A (en) * | 2020-03-19 | 2020-06-12 | 季春 | Low-cost drive circuit of programming device VPP high-voltage circuit |
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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: 20120118 Termination date: 20130516 |