CN201995176U

CN201995176U - LED lighting drive circuit

Info

Publication number: CN201995176U
Application number: CN2011200390201U
Authority: CN
Inventors: 刘福香
Original assignee: Chengdu Wish Instruments Co Ltd of CAS
Current assignee: Chengdu Wish Instruments Co Ltd of CAS
Priority date: 2011-02-15
Filing date: 2011-02-15
Publication date: 2011-09-28
Anticipated expiration: 2021-02-15

Abstract

The utility model discloses an LED lighting drive circuit comprising a power supply unit for outputting a constant current, a dimming signal unit, a control signal unit, a control core unit U2 and a failure detection unit. The LED lighting drive circuit ensures consistent LED brightness, realizes the shimmer of the lighting, has a failure detection function, guarantees the current consistency, improves a threshold voltage at a failure output end GZ, prevents misreports caused by interference, has a small number of circuit elements and a small size, is convenient to mount, and has low cost, and DD311 adopts a TO-252 encapsulation.

Description

The LED illumination driving circuit

Technical field

The utility model relates to a kind of illumination driving circuit.

Background technology

Under the background that global energy shortage, environmental requirement improve constantly, the green energy conservation illumination is all greatly developed in countries in the world.Have luminous efficiency height (one two watts LED is equivalent to 15 watts incandescent lighting), power consumption little (power consumption have only general lighting 1/10), advantage such as the life-span is long, volume is little, be considered to the revolution again of illumination after incandescent lamp, fluorescent lamp, the LED illumination is as a kind of revolutionary energy-saving illumination technology, just in develop rapidly.Yet the requirement of led drive circuit is also improving constantly.High efficiency, High Power Factor, high Current Control precision, high reliability, volume is little, cost is low etc. just becoming the crucial evaluation index of LED driving power.

LED is widely used at present, and numerous integration products emerge, and promptly LED driving power and LED lamp combine, and uses in different fields, has made things convenient for the user directly to use.Conventional led drive circuit uses as power supply and directly the LED lamp bar after LED lamp or the connection in series-parallel is lighted illumination, LED is applied in other field and purposes, the break-make of needs control LED illumination, flicker, failure diagnosis etc., and to guarantee the adjustment of LED brightness uniformity, the conventional driving just can not meet the demands.

Summary of the invention

The purpose of this utility model just is to provide a kind of address the above problem, the LED illumination driving circuit that can realize light on and off, failure diagnosis and the illumination flicker of light intensity linear regulation, control illumination.

To achieve these goals, the technical solution adopted in the utility model is such: a kind of LED illumination driving circuit comprises power supply unit, be used to export constant current, also comprise the dim signal unit, control signal unit U2, the control core cell, fault detection unit;

With the dim signal unit that described power supply unit output links to each other, be used for the linear regulation of light intensity;

With the control signal unit that described power supply unit output links to each other, be used to control the break-make of output current and regulate the control signal duty ratio;

Control core cell U2 input links to each other with control signal unit output with the dim signal unit respectively;

With the fault detection unit that the output of described control core cell U2 links to each other, be used to guarantee the consistency of electric current, the failure output terminal GZ at fault detection unit improves threshold voltage simultaneously.

As preferably: the input power supply of power supply unit is direct current+24V.

As preferably: the input current I of power supply unit _RefIn 0～10mA scope, adjust output current I _OutPress I _Out=100I _RefRelation output.

As preferably: the input current I of described power supply unit _RefBy adjusting plug-in resistance R ₂Or potentiometer or bias voltage V _bSet.

As preferably: described control core cell U2 is LED chip for driving DD311.

Compared with prior art, advantage of the present utility model is:

1. can see through and adjust input current I _RefSet output current I arbitrarily _OutSize, realize constant output current I _Out, fine setting bias voltage V _bBrightness between recoverable LED differs or realizes that the plurality of LEDs overall brightness adjusts simultaneously.

2. input current I _RefIn 0～10mA scope, adjust output current I _OutPress I _Out=100I _RefRelation output, the linear regulation of realization light intensity, the constant-current characteristics of drive circuit has guaranteed LED brightness unanimity.

3. the input voltage of control unit is controlled output current I _OutBreak-make, thereby the light on and off of control illumination, the pulse signal of importing certain duty ratio at control unit can be realized the flicker of throwing light on.

4. have fault diagnosis functions, guarantee the consistency of electric current, improve threshold voltage at failure output terminal GZ simultaneously, prevent owing to disturb the wrong report that causes.

5. circuit element quantity is few, and DD311 adopts the encapsulation of TO-252, and volume is little, and entire circuit is convenient installs.

6. system cost is low.

Description of drawings

Fig. 1 is an operation principle block diagram of the present utility model;

Fig. 2 is drive circuit figure of the present utility model;

Fig. 3 is the expanded application circuit diagram of drive circuit.

Embodiment

The utility model is described in further detail below in conjunction with accompanying drawing.

Referring to Fig. 1 to Fig. 3, the utility model comprises power supply unit, is used to export constant current, also comprises the dim signal unit, control signal unit, control core cell U2, fault detection unit;

With the fault detection unit that the output of described control core cell U2 links to each other, be used to guarantee the consistency of electric current, the failure output terminal GZ at fault detection unit improves threshold voltage simultaneously, prevents owing to disturb the wrong report that causes.

The input power supply of power supply unit is direct current+24V.

The input current I of power supply unit _RefIn 0～10mA scope, adjust output current I _OutPress I _Out=100I _RefRelation output.

The input current I of described power supply unit _RefBy adjusting plug-in resistance R ₂Or potentiometer or bias voltage V _bSet.

Described control core cell U2 is LED chip for driving DD311, and DD311 adopts the encapsulation of TO-252.

Its groundwork principle is: input current I is regulated in the dim signal unit _RefSet output current I arbitrarily _OutSize, realize constant output current I _RefThereby, realize all linear regulation of even light intensity of LED brightness.As required with control signal unit input V _ENThe fixedly light on and off of input high level or low level control LED illumination; As control signal unit input V _ENThe pulse signal (high level is greater than 3.3VDC) of importing certain duty ratio can be realized the flicker of throwing light on.Difference at the LED junction voltage of different colours, on circuit, designed D1 to D13, D1 to D13 is rectifier diode 1N4007, LED junction voltage according to concrete color calculates the number of D1 to D13 at circuit, guarantee the consistency of electric current, utilize D1, D2 to improve threshold voltage at the failure output terminal GZ of fault detection unit simultaneously, prevent owing to disturb the wrong report that causes.

As shown in Figure 2:

The power supply of entire circuit is direct current+24V, input power supply direct current+24V, and one the tunnel offers the circuit electricity consumption, and it is the power supply of led light source that another road offers the LED+ end, and the led light source other end just has drive circuit to control input current I _RefDrive circuit+24VDC inputs to U1 so, and U1 is three terminal regulator LM7815, and conversion output+15DC supplies with device electricity consumption in the circuit such as control core cell U2, fault detection unit again.

Control signal inputs to control core cell U2 through R1, dim signal inputs to control core cell U2 through R2 or RP2, fault detection signal is through D1, D2, R8 exports to the anode of U3, and U3 is voltage comparator LM139, compares output level voltage with the reference voltage of negative terminal, light source works just often, output high level (be about+15VDC); When light source works is undesired, output low level (being about power supply ground).The variation that all these input signals cause is all passed through 2 pin of control core cell U2 through D1, and D2, D3 to D13 export to the LED-end, and reaction is corresponding on light source changes.

As shown in Figure 3:

The power supply of entire circuit is direct current+24V, input power supply direct current+24V, and one the tunnel offers the circuit electricity consumption, and it is the power supply of led light source that another road provides " LED+ " end, and the led light source other end just has drive circuit to control input current I _RefDrive circuit+24VDC inputs to U1 so, and conversion output+15DC supplies with device electricity consumption in the circuit such as control core cell U2, fault detection unit, and the while is bright always through the 5 foot control system power supplys that R1 inputs to U2.

Dim signal inputs to control core cell U2 through R2 or RP2, and fault detection signal is through D1, and D2, R8 export to the anode of U3, compares output level voltage with the reference voltage of negative terminal, light source works just often, the output high level (be about+15VDC); When light source works is undesired, output low level (being about power supply ground).The variation that all these input signals cause is all passed through 2 pin of control core cell U2 through D1, and D2, D3 to D10 export to " LED-" end, and reaction is corresponding on light source changes.

Claims

1. a LED illumination driving circuit comprises power supply unit, is used to export constant current, it is characterized in that: also comprise the dim signal unit, control signal unit, control core cell U2, fault detection unit;

2. LED illumination driving circuit according to claim 1 is characterized in that: the input power supply of power supply unit is direct current+24V.

3. LED illumination driving circuit according to claim 2 is characterized in that: the input current I of power supply unit _RefIn 0～10mA scope, adjust output current I _OutPress I _Out=100I _RefRelation output.

4. LED illumination driving circuit according to claim 3 is characterized in that: the input current I of described power supply unit _RefBy adjusting plug-in resistance R ₂Or potentiometer or bias voltage V _bSet.

5. LED illumination driving circuit according to claim 1 is characterized in that: described control core cell U2 is LED chip for driving DD311.