CN102762011B - LED (Light Emitting Diode) constant-current dimming drive circuit device - Google Patents
LED (Light Emitting Diode) constant-current dimming drive circuit device Download PDFInfo
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- CN102762011B CN102762011B CN201110111816.8A CN201110111816A CN102762011B CN 102762011 B CN102762011 B CN 102762011B CN 201110111816 A CN201110111816 A CN 201110111816A CN 102762011 B CN102762011 B CN 102762011B
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Abstract
The invention provides an LED (Light Emitting Diode) constant-current dimming drive circuit device which comprises a rectifier unit, a filter unit, a constant-current driving unit and a dimming control unit, wherein the output end of the rectifier unit is connected to a first I/O (Input/Output) pin of a singlechip computer IC2 through a divider resistor R2; the first I/O pin of the singlechip computer IC2 is also grounded through a dimming potentiometer W1; a second I/O pin of the singlechip computer IC2 is connected to an enabling end of a control chip IC1 through a current-limiting resistor R3; and when the resistance of the dimming potentiometer W1 is adjusted, the second I/O pin of the singlechip computer IC2 outputs a PWM (Pulse Width Modulation) pulse signal, so that the control chip IC1 is positioned in a disconnection or connection work state. Due to the combination of an integrated control chip with low cost and high efficiency with the singlechip computer, the LED constant-current dimming drive circuit device has the advantages of high efficiency, reliability, low price, simple structure and the like.
Description
Technical field
The invention belongs to lighting technical field, be specifically related to a kind of LED constant current dimming driving circuit device.
Background technology
Along with the development of science and technology, new product, new technology are constantly reformed, and LED is as new type light source, it has energy-saving and environmental protection, efficiently feature, technology is ripe and be applied to every field, and LED is widely used as light source, has also occurred various LED drive circuit thereupon.All adopt DC/DC wave chopping technology to carry out driving LED at present in the place of low-voltage.
Chopper circuit referred to originally in power operation, needs, a part for sine wave " cut away " for certain.(such as when voltage is 50V, with electronic component, 50-0V part is below ended, output voltage is 0.) used in DC/DC switching circuit afterwards, mainly in Switching Power Supply pressure regulation process, the originally power supply of straight line, " is cut " pulse having become a piece a piece by circuit.
DC/DC chopping switch circuit has the advantages such as power consumption is little, efficiency is high, reliable and stable, unit power volume is little, lightweight, but its cost is high, circuit is complicated, fragile, have the shortcomings such as stronger High-frequency Interference, bring inconvenience to user.
Summary of the invention
Problem to be solved by this invention is to provide a kind of with low cost, structure is simple, high efficient and reliable, simply light LED constant current dimming driving circuit device, can ensure the work that LED is reliable and stable under constant current state, and can regulate the brightness of LED by changing constant current value.
For reaching above object, the present invention by the following technical solutions:
A kind of LED constant current dimming driving circuit device, comprises rectification unit, filter unit and constant current driving unit;
Described constant-current dimming driving circuit device, also comprises dimming control unit;
Described constant current driving unit comprises control chip IC1;
Described dimming control unit comprises single-chip microcomputer IC2, light adjusting potentiometer W1, divider resistance R1, divider resistance R2, current-limiting resistance R3 and pull down resistor R4;
The output of described rectification unit is connected to an I/O pin of described single-chip microcomputer IC2 by divider resistance R2, the one I/O pin of described single-chip microcomputer IC2 is also by described light adjusting potentiometer W1 ground connection, the 2nd I/O pin of described single-chip microcomputer IC2 is connected to the Enable Pin of described control chip IC1 by described current-limiting resistance R3, the 2nd I/O pin of described single-chip microcomputer IC2 is also by described pull down resistor R4 ground connection; When regulating the resistance size of described light adjusting potentiometer W1, the 2nd I/O pin of described single-chip microcomputer IC2 exports a pwm pulse signal, makes described control chip IC1 be in the operating state of shutoff or conducting;
The output of described rectification unit is also connected to the power input pin of described single-chip microcomputer IC2 by described divider resistance R1; Meanwhile, the power input pin of described single-chip microcomputer IC2 by described voltage stabilizing didoe ZD1 ground connection, described voltage stabilizing didoe ZD1 by the voltage control of the power input pin of described single-chip microcomputer IC2 in the operating voltage range of described single-chip microcomputer IC2.
Described rectification unit adopts bridge-type rectifier bridge.
Described LED constant current dimming driving circuit device, also comprises: overtemperature protection unit; Described overtemperature protection unit comprises: negative tempperature coefficient thermistor and divider resistance R6;
One end of described negative tempperature coefficient thermistor is connected to the output of described rectification unit; The other end of described negative tempperature coefficient thermistor is connected with the 3rd I/O pin of described single-chip microcomputer IC2, and the other end of described negative tempperature coefficient thermistor is also by described divider resistance R6 ground connection.
Described constant current driving unit also comprises ballast inductance L1, sustained diode 2 and sampling resistor R5;
The power input of described control chip IC1 is connected to the output of described rectification unit; One end of described ballast inductance L1 is connected with the output of described rectification unit and the power input of described control chip IC1 simultaneously; The other end of described ballast inductance L1 and the anode of described sustained diode 2 are connected to the output of described control chip IC1 jointly; The negative electrode of described fly-wheel diode is connected with the anode tap of LED; The cathode terminal of described LED accesses the feedback end of described control chip IC1; Described sampling resistor is connected between the feedback end of described control chip IC1 and ground end.
The invention has the beneficial effects as follows:
Drive circuit provided by the present invention, adopts with low cost and efficient integrating control chip combination with the MCU, and composition constant-current dimming driving circuit device had both been planned as a whole the advantage system of Switching Power Supply, and had again with low cost, advantages of simple structure and simple simultaneously; And under LED light source can be made reliablely and stablely to be operated in constant current state, and brightness is adjustable.
Accompanying drawing illustrates:
Fig. 1 is the building-block of logic of a specific embodiment of a kind of LED constant current dimming driving circuit of the present invention device;
Fig. 2 is the circuit arrangement figure of a specific embodiment of a kind of LED constant current dimming driving circuit of the present invention device.
Embodiment:
In order to make object of the present invention, technical scheme and advantage clearly understand, below in conjunction with drawings and Examples, a kind of LED dimming driving circuit device of the present invention is further elaborated.Should be appreciated that specific embodiment described herein only in order to explain the present invention, be not intended to limit the present invention.
As Fig. 1, in the building-block of logic of a specific embodiment of a kind of LED constant current dimming driving circuit of the present invention device, comprise rectification unit 1, filter unit 2, constant current driving unit 3, dimming control unit 4 and overtemperature protection unit 5;
Further, rectification unit 1 to filter unit 2, constant current driving unit 3, dimming control unit 4, overtemperature protection unit 5 and LED export direct current; Constant current driving unit 3 is connected between rectification unit 1 and LED, and the feedback signal for the current sample according to LED adjusts the electric current of LED, and control LED works under constant current state; Dimming control unit 4 is connected with constant current driving unit 3 with rectification unit 1, for exporting control signal to constant current driving unit 3, and regulates and controls the brightness of LED by constant current driving unit 3.
Fig. 2 shows the circuit arrangement figure of the present invention one specific embodiment, for convenience of description, illustrate only part related to the present embodiment;
With reference to Fig. 2, preferably, in the present embodiment, rectification unit 1 comprises power supply, control switch K1 and bridge-type rectifier bridge stack D1;
Further, rectifier bridge stack D1 is made up of four diodes, includes four nodes:
Node 1, is connected with one end of power supply by control switch K1;
Node 2, as the output of rectification unit 1;
Node 3, is directly connected with the other end of power supply;
Node 4, ground connection.
In the present embodiment, constant current driving control unit 2 comprises control chip IC1, ballast inductance L1, sustained diode 2 and current sampling resistor R5;
Preferably, the control chip IC1 in the present embodiment, employing model is the booster type current constant control chip of BP1601; BP1601 chip comprises eight ports, is respectively: power earth terminal GNDP, power input VIN, overvoltage test side OV, Enable Pin EN, signal ground end GNDA, feedback signal input terminal FB, power take-off SW and free end NC;
One end of ballast inductance L1, simultaneously with the output of rectification unit 1, and the power input VIN of control chip IC1 connects;
The other end of ballast inductance L1, is connected to the power take-off SW of control chip IC1 jointly with the anode of sustained diode 2; The negative electrode of fly-wheel diode is connected with the anode tap of LED; The cathode terminal of described LED accesses the feedback end of described control chip IC1; Described sampling resistor R5 is connected between the feedback end of described control chip IC1 and ground end.
Further, control chip IC1 is by controlling conducting and the turn-off time of power take-off SW, and then control voltage storage and the release at L1 two ends, ballast inductance, the voltage superposition of the voltage that ballast inductance L1 is discharged and the output of rectification unit 1, complete boost process, and by sustained diode 2, make LED at stable operating at voltages.
Preferably, the input voltage range required by BP1601 chip is 4.5V-24V; Therefore, in the present embodiment, the power supply adopted in power output unit 1 is: AC/DC 4.5V-24V, maximum output current 1A, power supply input is regardless of both positive and negative polarity.
Further, in the LED constant current dimming driving circuit device that this implementation column provides, the operation principle of constant current driving unit 2 is: after control switch K1 is closed, the power input VIN of control chip IC1 and Enable Pin EN obtains electric work, and power take-off SW end is opened; Current sampling signal is delivered to the internal comparator of control chip IC1 by feedback signal input terminal FB, control chip IC1 is again according to conducting and the turn-off time of the difference Modulating Power output SW compared, and then realize the control flowing through LED current, reach the object of constant current.
Further, BP1601 chip adopts the method for Current Control to carry out driving LED, and its principle is: set LED current by sampling resistor, and sampled voltage can be low to moderate 200mv, to reduce system loss, to improve system effectiveness; Therefore, in the present embodiment, the negative electrode of LED to be connected with one end of current sampling resistor R5 and the feedback signal input terminal FB of access control chip IC 1; The other end ground connection of current sampling resistor R5.
Preferably, by the voltage control of feedback signal input terminal FB at 200mv, change the resistance size of current sampling resistor R5, also can change the size of control chip IC1 output current.
In the present embodiment, dimming control unit 3 comprises single-chip microcomputer IC2, light adjusting potentiometer W1, divider resistance R1, divider resistance R2, current-limiting resistance R3 and pull down resistor R4;
Further, in the present embodiment, as shown in Figure 2, light modulation single-chip microcomputer IC2 comprises 8 pins, is respectively: power input pin VCC, grounding pin GND, one I/O pin (namely as reference voltage pin PB0), 2nd I/O pin (namely as control signal output pin PB4), the 3rd I/O pin (namely as step-down pin PB1), and unsettled pin PB2, PB3;
Wherein, reference voltage pin pin PB0 is connected to the output of rectification unit 1 by divider resistance R2, and meanwhile, reference voltage pin pin PB0 is also by described light adjusting potentiometer W1 ground connection; Control signal output pin PB4 is connected to the Enable Pin EN of control chip IC1 by current-limiting resistance R3, meanwhile, control signal output pin PB4 is also by pull down resistor R4 ground connection; Power input pin VCC is connected to the output of rectification unit 1 by divider resistance R1;
Further, voltage stabilizing didoe ZD1 is connected between the power input pin VCC of single-chip microcomputer IC2 and grounding pin GND, is used for the voltage control of the power input pin VCC of single-chip microcomputer IC2 in the operating voltage range of single-chip microcomputer IC2.
Further, in the present embodiment, the operation principle of dimming control unit 3 is: when regulating the resistance size of W1, also just changing the magnitude of voltage size of reference voltage pin PB0 in single-chip microcomputer IC2, and then the A/D value size of reference voltage pin PB0 is also changed; Single-chip microcomputer IC2 changes according to the A/D value of reference voltage pin PB0, adjustment pwm pulse (Pulse Width Modulation, pulse width modulation) the duty ratio of low and high level, pwm pulse after adjustment is added to the Enable Pin EN of control chip IC1 by control signal output pin PB4, because the low and high level of the Enable Pin of control chip IC1 can control opening of control chip IC1 and turn off; Therefore, control chip IC1 opens according to Enable Pin EN according to the change of the duty ratio of the low and high level of pwm pulse and turns off, be equivalent on the basis of constant current, again through carrying out the output of Modulating Power output SW to the switch of current constant control chip IC 1, thus change the size of the electric current on LED, achieve the object of light modulation.
In the present embodiment, overtemperature protection unit 5 is also comprised; Overtemperature protection unit 5 comprises: negative tempperature coefficient thermistor RT1, divider resistance R6; One end of negative tempperature coefficient thermistor RT1 is connected to the output of rectification unit 1; The other end of negative tempperature coefficient thermistor RT1 is connected with the step-down pin PB1 of single-chip microcomputer IC2, and the other end of negative tempperature coefficient thermistor RT1 is also by divider resistance R6 ground connection.
Because the characteristic of negative tempperature coefficient thermistor RT1 is: temperature raises, resistance reduces; Therefore when the temperature of LED exceeds the temperature range of the environment for use preset, the resistance value of RT1 reduces, the voltage of the step-down pin PB1 of single-chip microcomputer IC2 is just made to increase, single-chip microcomputer IC2 is by the change according to step-down pin PB1 numerical value, change the PWM pulsewidth that control signal output pin PB4 exports, and then reduce the electric current of LED; LED is avoided to burn out because temperature is too high or accelerate light decay.
Further, in the LED dimming driving circuit device that the present embodiment provides, in order to ensure that input voltage does not fluctuate by ectocine, between the node 2 and node 4 of rectifier bridge stack D1, be parallel with filter unit 2; Filter unit 2 comprises: filtering and storage source electric capacity C1 and filter capacitor C2.
Preferably, in the present embodiment, in order to ensure that the voltage at LED two ends does not fluctuate by ectocine, be parallel with filtering and storage source electric capacity C3 at the two ends of LED, one end of filtering and storage source electric capacity C3 is connected to the positive terminal of LED, other end ground connection.
Cheap and the structure of the circuit cost of this fact Example is simple, efficient; And LED circuit steady operation under the state of constant current can be made, and LED light source brightness can be made adjustable by the pulsewidth changing the pwm pulse that single-chip microcomputer exports.
Finally it should be noted that obviously, those skilled in the art can carry out various change to the present invention and not depart from the spirit and scope of the present invention; If belong within the scope of the claims in the present invention and equivalent technologies thereof to these amendments of the present invention, then the present invention is also intended to comprise these changes.
Claims (4)
1. a LED constant current dimming driving circuit device, comprises rectification unit, filter unit and constant current driving unit; It is characterized in that: also comprise dimming control unit;
Described constant current driving unit comprises control chip IC1;
Described dimming control unit comprises single-chip microcomputer IC2, light adjusting potentiometer W1, divider resistance R1, divider resistance R2, current-limiting resistance R3 and pull down resistor R4;
The output of described rectification unit is connected to an I/O pin of described single-chip microcomputer IC2 by divider resistance R2, the one I/O pin of described single-chip microcomputer IC2 is also by described light adjusting potentiometer W1 ground connection, the 2nd I/O pin of described single-chip microcomputer IC2 is connected to the Enable Pin of described control chip IC1 by described current-limiting resistance R3, the 2nd I/O pin of described single-chip microcomputer IC2 is also by described pull down resistor R4 ground connection; When regulating the resistance size of described light adjusting potentiometer W1, described single-chip microcomputer IC2 exports a pwm pulse signal according to the A/D value change of an I/O pin from the 2nd I/O pin, makes described control chip IC1 be in the operating state of shutoff or conducting according to the change of the duty ratio of the low and high level of pwm pulse signal;
The output of described rectification unit is also connected to the power input pin of described single-chip microcomputer IC2 by described divider resistance R1; Meanwhile, the power input pin of described single-chip microcomputer IC2 by described voltage stabilizing didoe ZD1 ground connection, voltage stabilizing didoe ZD1 by the voltage control of the power input pin of described single-chip microcomputer IC2 in the operating voltage range of described single-chip microcomputer IC2.
2. LED constant current dimming driving circuit device according to claim 1, is characterized in that,
Described rectification unit adopts bridge-type rectifier bridge.
3. LED constant current dimming driving circuit device according to claim 1, is characterized in that,
Also comprise: overtemperature protection unit; Described overtemperature protection unit comprises: negative tempperature coefficient thermistor and divider resistance R6;
One end of described negative tempperature coefficient thermistor is connected to the output of described rectification unit; The other end of described negative tempperature coefficient thermistor is connected with the 3rd I/O pin of described single-chip microcomputer IC2, and the other end of described negative tempperature coefficient thermistor is also by described divider resistance R6 ground connection.
4. LED constant current dimming driving circuit device according to claim 1, is characterized in that,
Described constant current driving unit also comprises ballast inductance L1, sustained diode 2 and sampling resistor R5;
The power input of described control chip IC1 is connected to the output of described rectification unit; One end of described ballast inductance L1 is connected with the output of described rectification unit and the power input of described control chip IC1 simultaneously; The other end of described ballast inductance L1 and the anode of described sustained diode 2 are connected to the output of described control chip IC1 jointly; The negative electrode of described fly-wheel diode is connected with the anode tap of LED; The cathode terminal of described LED accesses the feedback end of described control chip IC1; Described sampling resistor is connected between the feedback end of described control chip IC1 and ground end.
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| CN201110111816.8A CN102762011B (en) | 2011-04-29 | 2011-04-29 | LED (Light Emitting Diode) constant-current dimming drive circuit device |
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| CN201110111816.8A CN102762011B (en) | 2011-04-29 | 2011-04-29 | LED (Light Emitting Diode) constant-current dimming drive circuit device |
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| CN102762011A CN102762011A (en) | 2012-10-31 |
| CN102762011B true CN102762011B (en) | 2015-03-11 |
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| CN102833902B (en) * | 2011-06-14 | 2015-09-23 | 海洋王照明科技股份有限公司 | Booster type constant current driver circuit for LED |
| CN103813564A (en) * | 2012-11-05 | 2014-05-21 | 海洋王（东莞）照明科技有限公司 | Lamp and protection circuit thereof |
| CN104427700B (en) * | 2013-09-04 | 2018-10-12 | 深圳市海洋王照明工程有限公司 | Overheating protection circuit, LED drive circuit and lamps and lanterns |
| CN104684185A (en) * | 2013-12-03 | 2015-06-03 | 深圳市海洋王照明工程有限公司 | LED (light emitting diode) lighting circuit |
| CN104768261A (en) * | 2014-01-02 | 2015-07-08 | 深圳市海洋王照明工程有限公司 | Dimming LED constant-current driving circuit |
| CN104768271B (en) * | 2014-01-02 | 2019-10-25 | 深圳市海洋王照明工程有限公司 | Constant current driver circuit for LED with an automatic light meter |
| CN104768267B (en) * | 2014-01-02 | 2019-02-01 | 深圳市海洋王照明工程有限公司 | Width funtion low-power LED constant-current drive circuit |
| CN104185344B (en) * | 2014-08-14 | 2016-11-16 | 京东方科技集团股份有限公司 | Control circuit for light source, backlight module and display device |
| CN104582142B (en) * | 2014-12-12 | 2017-06-23 | 骆武宁 | The stepless dimming control method of illuminator |
| CN105338718B (en) * | 2015-12-08 | 2018-09-18 | 王汉忠 | It is a kind of based on linearly with the LED constant current driving method and device of PWM operating modes |
| CN107148111B (en) * | 2017-05-26 | 2019-04-16 | 东莞华明灯具有限公司 | A kind of LED control circuit of multiple-channel output |
| CN110213857A (en) * | 2019-06-21 | 2019-09-06 | 惠州市莱特照明科技有限公司 | LED drive circuit |
| CN112333887B (en) * | 2020-10-14 | 2023-03-14 | 深圳篆意科技有限公司 | LED drive circuit |
| CN112399672A (en) * | 2020-11-02 | 2021-02-23 | 厦门市义圆源科技有限公司 | Dimming lamp tube compatible with electronic ballast |
| CN114340094A (en) * | 2022-01-12 | 2022-04-12 | 广东恒润光电有限公司 | LED driving over-temperature protection control method and circuit |
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