CN203136265U - Circuit and device for LED constant current driving - Google Patents
Circuit and device for LED constant current driving Download PDFInfo
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- CN203136265U CN203136265U CN 201320091213 CN201320091213U CN203136265U CN 203136265 U CN203136265 U CN 203136265U CN 201320091213 CN201320091213 CN 201320091213 CN 201320091213 U CN201320091213 U CN 201320091213U CN 203136265 U CN203136265 U CN 203136265U
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Abstract
The utility model discloses an LED constant current driving circuit, respectively connected with a main controller, a DC constant voltage power supply, and a light bar module. The LED constant current driving circuit comprises a drive control module, a constant current driver module, and an overvoltage protection module. The constant current driver module is connected with the DC constant voltage power supply through the drive control module. A control end of the drive control module is connected with the main controller. An input end of the constant current driver module is connected with a negative terminal of the light bar module. A positive terminal of the light bar module is connected with the DC constant voltage power supply. An input end of the overvoltage protection module is connected with a negative terminal of the light bar module, and an output end is connected with the control end of the drive control module. The utility model also discloses an LED constant current driving device, comprising the above LED constant current driving circuit. The LED constant current driving circuit can flexibly adjust current in each path of light bar, so that current in each path of light bar is equal, thereby realizing constant current driving of the light bars, improving performance of the circuit and reliability, improving EMI characteristic of the circuit, and reducing cost.
Description
Technical field
The utility model relates to LED Driving technique field, relates in particular to a kind of LED constant-current drive circuit and device.
Background technology
In the prior art, mainly be to adopt traditional constant-current drive circuit for the drive circuit of LED lamp, comprise Boost booster circuit, constant current sampling equalizing control circuit, and some overcurrent-overvoltage protecting circuits.Because LED lamp series connection number and single LED lamp conducting voltage need rise to certain voltage value with input voltage in the lamp bar, to guarantee the needs of LED lamp string constant current conducting, this just needs the Boost booster circuit to boost.In addition, need constant current sampling equalizing control circuit to the control of taking a sample of lamp bar electric current, to reach the purpose of constant current driving at lamp bar negative terminal.
At present, the Boost booster circuit that led drive circuit adopts, by integrated circuit the MOSFET pipe being carried out frequency in when work is that tens to up to a hundred hertz accent bandwidth signals is controlled, this will inevitably cause space radiation or circuit EMI(Electro Magnetic Interference, electromagnetic interference) deterioration of characteristic, and because the control circuit complexity need spend bigger energy when parts selection, if the circuit design imperfection then causes serious safety problems such as MOSFET pipe damage easily.
In addition, constant current sampling equalizing control circuit adopts integrated circuit to reach stable constant current control function more, but the price of this kind integrated circuit is expensive at present, and the application restriction that needs are controlled cost is bigger.
The utility model content
Main purpose of the present utility model is to propose a kind of LED constant-current drive circuit and device, is intended to improve the Performance And Reliability of circuit, improves the EMI characteristic of circuit, reduces cost.
In order to achieve the above object, the utility model proposes a kind of LED constant-current drive circuit, this LED constant-current drive circuit is connected with master controller, dc constant voltage power supply and lamp bar module respectively, this LED constant-current drive circuit comprises for the described dc constant voltage power supply of the control drive control module of whether powering, be used for driving the constant-current driven module that the lamp bar constant current of described lamp bar module is lighted, and be used for the output over-voltage protection signal to described drive control module, to cut off the overvoltage protective module of described dc constant voltage power supply output; Wherein:
The input of described drive control module is connected with described dc constant voltage power supply, and its control end is connected with described master controller, and its output is connected with the control end of described constant-current driven module; The input of described constant-current driven module is connected with the negative terminal of described lamp bar module, and the anode of described lamp bar module is connected with described dc constant voltage power supply; The input of described overvoltage protective module is connected with the negative terminal of described lamp bar module, and its output is connected with the control end of described drive control module.
Preferably, described drive control module comprises first triode, second triode, a diode, first resistance, second resistance, the 3rd resistance, the 4th resistance and resistance and joint group, and described resistance and joint group comprise a plurality of resistance parallel with one another; Wherein:
The emitter of described first triode is connected with described dc constant voltage power supply, the base stage of described first triode is connected with described dc constant voltage power supply through described first resistance, and be connected with the collector electrode of described second triode through described second resistance, the collector electrode of described first triode is connected with described constant-current driven module through described resistance and joint group; The base stage of described second triode is divided into three the tunnel behind described the 3rd resistance; the first via is connected with the simulation dim signal output of described master controller; the second the tunnel with the PWM(Pulse Width Modulation of described master controller; pulse width modulation) duty ratio dim signal input connects; Third Road is connected with the backlight signal output of described master controller through described diode; the base stage of described second triode is connected with the output of described overvoltage protective module; and through described the 4th grounding through resistance, the grounded emitter of described second triode.
Preferably, described drive control module also comprises the 5th resistance, the 6th resistance, first electric capacity, second electric capacity and the 3rd electric capacity; Described the 5th resistance is connected between described the 3rd resistance and the described simulation dim signal output, described the 6th resistance is connected between described the 3rd resistance and the described PWM duty ratio dim signal output, described first electric capacity is in parallel with described first resistance, described second electric capacity is in parallel with described the 4th resistance, and described resistance and joint group are through described the 3rd capacity earth.
Preferably, described constant-current driven module comprises amplifying unit and some driver elements, wherein a described driver element is connected with described amplifying unit, the corresponding connection of negative terminal of the street lamp bar in the input of each described driver element and the described lamp bar module, the control end of each described driver element is connected with the output of described drive control module.
Preferably, each described driver element comprises that one drives triode and a sample resistance; The negative terminal of the street lamp bar in the collector electrode of described driving triode and the described lamp bar module is connected, the emitter of described driving triode is through described sample resistance ground connection, the base stage of described driving triode is connected with the output of described drive control module as the control end of described driver element.
Preferably, described amplifying unit comprises first amplifying triode, the 7th resistance and the 8th resistance; The base stage of described first amplifying triode is connected with the emitter of described driving triode through described the 7th resistance, and through described the 8th grounding through resistance, the collector electrode of described first amplifying triode is connected with the base stage of described driving triode, the grounded emitter of described first amplifying triode.
Preferably, described amplifying unit comprises first amplifying triode, second amplifying triode, the 7th resistance and the 8th resistance; The base stage of described first amplifying triode is connected with the emitter of described driving triode through described the 7th resistance, and through described the 8th grounding through resistance, the collector electrode of described first amplifying triode is connected with the base stage of described second amplifying triode, the grounded emitter of described first amplifying triode; The emitter of described second amplifying triode is connected with the base stage of described driving triode, the grounded collector of described second amplifying triode.
Preferably, described overvoltage protective module comprises the 3rd triode, the 9th resistance, the tenth resistance, the 11 resistance, a voltage-stabiliser tube and some protection tubes; The negative terminal of the street lamp bar in the anode of each described protection tube and the described lamp bar module is connected; the negative electrode of each described protection tube is through described the 9th grounding through resistance; and be connected with an end of described the tenth resistance through described voltage-stabiliser tube; the other end of described the tenth resistance is connected with the base stage of described the 3rd triode; and through described the 11 grounding through resistance; the grounded emitter of described the 3rd triode, the collector electrode of described the 3rd triode is connected with the control end of described drive control module.
The utility model also proposes a kind of LED constant current driving device, this LED constant current driving device comprises master controller, dc constant voltage power supply and lamp bar module, also comprise the LED constant-current drive circuit, described LED constant-current drive circuit respectively with described master controller, described dc constant voltage power supply is connected with described lamp bar module, this LED constant-current drive circuit comprises the drive control module of whether powering for the described dc constant voltage power supply of control, be used for to drive the constant-current driven module that the lamp bar constant current of described lamp bar module is lighted, and be used for the output over-voltage protection signal to described drive control module, to cut off the overvoltage protective module of described dc constant voltage power supply output; Wherein:
The input of described drive control module is connected with described dc constant voltage power supply, and its control end is connected with described master controller, and its output is connected with the control end of described constant-current driven module; The input of described constant-current driven module is connected with the negative terminal of described lamp bar module, and the anode of described lamp bar module is connected with described dc constant voltage power supply; The input of described overvoltage protective module is connected with the negative terminal of described lamp bar module, and its output is connected with the control end of described drive control module.
The LED constant-current drive circuit that the utility model proposes; power to constant-current driven module by drive control module control dc constant voltage power supply; light with the lamp bar that drives in the lamp bar module by constant-current driven module; and adjust electric current in each street lamp bar; make the electric current of every street lamp bar equate; realization drives the constant current of lamp bar; make circuit performance more stable; and; when in the lamp bar LED short circuit being arranged;, power to constant-current driven module to cut off the dc constant voltage power supply to drive control module output over-voltage protection signal by overvoltage protective module, improve the reliability of circuit.Simultaneously, the utility model LED constant-current drive circuit is with respect to prior art, do not need by the Boost booster circuit input voltage to be boosted, the direct voltage that directly utilizes the dc constant voltage power supply to export is powered to drive the lamp bar for the lamp bar and is lighted, and has improved the EMI characteristic of circuit effectively.In addition, the utility model LED constant-current drive circuit only adopts simple discrete component can realize the function of circuit, reduces cost effectively.
Description of drawings
Fig. 1 is the theory diagram of the utility model LED constant current driving device preferred embodiment;
Fig. 2 is the electrical block diagram of drive control module preferred embodiment in the utility model LED constant-current drive circuit;
Fig. 3 is the electrical block diagram of constant-current driven module one embodiment in the utility model LED constant-current drive circuit;
Fig. 4 is the electrical block diagram of another embodiment of constant-current driven module in the utility model LED constant-current drive circuit;
Fig. 5 is the electrical block diagram of overvoltage protective module preferred embodiment in the utility model LED constant-current drive circuit.
The realization of the purpose of this utility model, functional characteristics and advantage will be in conjunction with the embodiments, and be described further with reference to accompanying drawing.
Embodiment
Further specify the technical solution of the utility model below in conjunction with Figure of description and specific embodiment.Should be appreciated that specific embodiment described herein only in order to explaining the utility model, and be not used in restriction the utility model.
The utility model proposes a kind of LED constant-current drive circuit.
With reference to Fig. 1, Fig. 1 is the theory diagram of the utility model LED constant current driving device preferred embodiment.
In the present embodiment; LED constant-current drive circuit 100 is connected with master controller 200 on the TV motherboard; and be connected with lamp bar module 400 with dc constant voltage power supply 300 respectively; LED constant-current drive circuit 100 comprises drive control module 110; constant-current driven module 120 and overvoltage protective module 130; whether drive control module 110 is used for control dc constant voltage power supply 300 and powers; constant-current driven module 120 is used for the lamp bar constant current of driving lamp bar module 400 and lights; overvoltage protective module 130 is used for the output over-voltage protection signal to drive control module 110, to cut off 300 outputs of dc constant voltage power supply.
Wherein, the input of drive control module 110 is connected with dc constant voltage power supply 300, and the control end of drive control module 110 is connected with master controller 200, and the output of drive control module 110 is connected with the control end of constant-current driven module 120; The input of constant-current driven module 120 is connected with the negative terminal of lamp bar module 400, and the anode of lamp bar module 400 is connected with dc constant voltage power supply 300; The input of overvoltage protective module 130 is connected with the negative terminal of lamp bar module 400, and the output of overvoltage protective module 130 is connected with the control end of drive control module 110.
LED constant-current drive circuit 100 of the present utility model; power to constant-current driven module 120 by drive control module 110 control dc constant voltage power supplys 300; light with the lamp bar that drives in the lamp bar module 400 by constant-current driven module 120; and adjust electric current in each street lamp bar; make the electric current of every street lamp bar equate; realization drives the constant current of lamp bar; make circuit performance more stable; and; when in the lamp bar LED short circuit being arranged; to drive control module 110 output over-voltage protection signals, to cut off dc constant voltage power supply 300 to constant-current driven module 120 power supplies, improve the reliability of circuit by overvoltage protective module 130.Simultaneously, the utility model LED constant-current drive circuit 100 is with respect to prior art, do not need by the Boost booster circuit input voltage to be boosted, the direct voltage that directly utilizes dc constant voltage power supply 300 to export is powered to drive the lamp bar for the lamp bar and is lighted, and has improved the EMI characteristic of circuit effectively.
In conjunction with Fig. 1 to Fig. 5, wherein Fig. 2 is the electrical block diagram of drive control module 110 preferred embodiments in the utility model LED constant-current drive circuit 100; Fig. 3 is the electrical block diagram of constant-current driven module 120 1 embodiment in the utility model LED constant-current drive circuit 100; Fig. 4 is the electrical block diagram of constant-current driven module 120 another embodiment in the utility model LED constant-current drive circuit 100; Fig. 5 is the electrical block diagram of overvoltage protective module 130 preferred embodiments in the utility model LED constant-current drive circuit 100.
In the present embodiment, as shown in Figure 2, drive control module 110 comprises the first triode Q11, the second triode Q12, diode D1, first resistance R 1, second resistance R 2, the 3rd resistance R 3, the 4th resistance R 4 and resistance and joint group 111, the first triode Q11 is the positive-negative-positive triode, the second triode Q12 is NPN type triode, and resistance and joint group 111 comprise a plurality of resistance parallel with one another.
Wherein, the emitter of the first triode Q11 is connected with dc constant voltage power supply 300, the base stage of the first triode Q11 is connected with dc constant voltage power supply 300 through first resistance R 1, and the base stage of the first triode Q11 is connected with the collector electrode of the second triode Q12 through second resistance R 2, and the collector electrode of the first triode Q11 is connected with constant-current driven module 120 through resistance and joint group 111; The base stage of the second triode Q12 is divided into three the tunnel after the 3rd resistance R 3, the simulation dim signal output V of the first via and master controller 200
AConnect, the second tunnel with the PWM duty ratio dim signal output V of master controller 200
PWMConnect, Third Road is through the backlight signal output V of diode D1 and master controller 200
BLConnect, the base stage of the second triode Q12 is connected with the output of overvoltage protective module 130, and the base stage of the second triode Q12 is through the 4th resistance R 4 ground connection, the grounded emitter of the second triode Q12.
Particularly, drive control module 110 also comprises the 5th resistance R 5, the 6th resistance R 6, first capacitor C 1, second capacitor C 2 and the 3rd capacitor C 3; The 5th resistance R 5 is connected in the 3rd resistance R 3 and simulation dim signal output V
ABetween, the 6th resistance R 6 is connected in the 3rd resistance R 3 and PWM duty ratio dim signal output V
PWMBetween, first capacitor C 1 is in parallel with first resistance R 1, and second capacitor C 2 is in parallel with the 4th resistance R 4, and resistance and joint group 111 are through the 3rd capacitor C 3 ground connection.
In the present embodiment, constant-current driven module 120 comprises amplifying unit 121 and some driver elements 122, and the quantity of driver element 122 is identical with the quantity of lamp bar in the lamp bar module 400; One of them driver element 122 is connected with amplifying unit 121, the corresponding connection of negative terminal of the street lamp bar in the input of each driver element 122 and the lamp bar module 400, and the control end of each driver element 122 is connected with the output of drive control module 110.
Particularly, each driver element 122 comprises driving triode Q21 and sample resistance RS, and driving triode Q21 is NPN type triode; Present embodiment only describes with a driver element 122, the negative terminal of the street lamp bar in the collector electrode that drives triode Q21 and the lamp bar module 400 is connected, drive the emitter of triode Q21 through sample resistance RS ground connection, drive the base stage of triode Q21 as the control end of driver element 122, be connected with the output of drive control module 110.
Particularly, as shown in Figure 3, amplifying unit 121 comprises that the first amplifying triode Q31, the 7th resistance R 7 and the 8th resistance R 8, the first amplifying triode Q31 are NPN type triode; Present embodiment only describes with a driver element 122, the base stage of the first amplifying triode Q31 is connected with the emitter that drives triode Q21 through the 7th resistance R 7, and the base stage of the first amplifying triode Q31 is through the 8th resistance R 8 ground connection, the collector electrode of the first amplifying triode Q31 is connected the grounded emitter of the first amplifying triode Q31 with the base stage that drives triode Q21.
In the present embodiment, as shown in Figure 4, amplifying unit 121 also has a kind of mapping mode, amplifying unit 121 comprises the first amplifying triode Q31, the second amplifying triode Q32, the 7th resistance R 7 and the 8th resistance R 8, the first amplifying triode Q31 is NPN type triode, and the second amplifying triode Q32 is the positive-negative-positive triode; The base stage of the first amplifying triode Q31 is connected with the emitter that drives triode Q21 through the 7th resistance R 7, and the base stage of the first amplifying triode Q31 is through the 8th resistance R 8 ground connection, the collector electrode of the first amplifying triode Q31 is connected with the base stage of the second amplifying triode Q32, the grounded emitter of the first amplifying triode Q31; The emitter of the second amplifying triode Q32 is connected the grounded collector of the second amplifying triode Q32 with the base stage that drives triode Q21.The multiple tube of being made up of the first amplifying triode Q31 and the second amplifying triode Q32 constitutes the feedback triode, because the multiplication factor of multiple tube is tens times of multiplication factor of the single first amplifying triode Q31, make that the adjusting of the electric current in 120 pairs of lamp bars of constant-current driven module is sensitiveer, and then it is higher to make constant current adjust precision.
Usually, form a basic constant current driving unit by amplifying unit 121 and driver element 122, each basic constant current driving unit can correspondingly drive a street lamp bar, and when the quantity of lamp bar more for a long time, circuit structure as shown in Figure 3 and Figure 4, adopt the interaction of an amplifying unit 121 and some driver elements 122, control and adjusting when realizing the electric current to multichannel lamp bar reaches the purpose that the constant current of multichannel lamp bar is driven.
In the present embodiment, adopt a plurality of resistance parallel with one another to constitute resistance and joint group 111, to improve the power that drives the lamp bar, make that the luminous effect of LED in the lamp bar is better, the quantity of resistance and resistance are according to the quantity of driver element 122 in resistance and the joint group 111, drive the multiplication factor of triode Q21, the first amplifying triode Q31 and the second amplifying triode Q32, and the current value that the lamp bar sets decides.
In the present embodiment, as shown in Figure 5, overvoltage protective module 130 comprises the 3rd triode Q13, the 9th resistance R 9, the tenth resistance R 10, the 11 resistance R 11, voltage-stabiliser tube D2 and some protection tube D3, the 3rd triode Q13 is NPN type triode, and the quantity of protection tube D3 is identical with the quantity of lamp bar in the lamp bar module 400; The negative terminal of the street lamp bar in the anode of each protection tube D3 and the lamp bar module 400 is connected; the negative electrode of each protection tube D3 is through the 9th resistance R 9 ground connection; and the negative electrode of each protection tube D3 is connected with an end of the tenth resistance R 10 through voltage-stabiliser tube D2; the other end of the tenth resistance R 10 is connected with the base stage of the 3rd triode Q13; and the other end of the tenth resistance R 10 is through the 11 resistance R 11 ground connection; the grounded emitter of the 3rd triode Q13, the collector electrode of the 3rd triode Q13 is connected with the control end of drive control module 110.
When the short circuit simultaneously of a short circuit or plurality of LEDs was arranged in the lamp bar, the voltage of the negative terminal of lamp bar will sharply increase, and the power consumption that causes driving triode Q21 increases, even caused driving triode Q21 to burn because heat generating spot is excessive, came risk for the complete machine safety belt.Present embodiment is by overvoltage protective module 130 output over-voltage protection signal when the LED short circuit is arranged, and control drive control module 110 cuts off the output of dc constant voltage power supply 300.
The specific descriptions of the operation principle of the utility model LED constant-current drive circuit 100 are as follows:
When powering on, the master controller 200 on the TV SKD is by its backlight signal output V
BL, simulation dim signal output V
AWith PWM duty ratio dim signal output V
PWMExport the base stage of backlight signal BL_on, simulation dim signal DIM_analog and the PWM duty ratio dim signal DIM_pwm second triode Q12 to the drive control module 110 respectively, backlight signal BL_on, simulation dim signal DIM_analog and PWM duty ratio dim signal DIM_pwm control the second triode Q12 conducting state simultaneously, namely as backlight signal BL_on, when simulation dim signal DIM_analog and PWM duty ratio dim signal DIM_pwm are high level, just conducting of the second triode Q12.When backlight the opening of television set liquid crystal display screen, backlight signal BL_on, simulation dim signal DIM_analog and PWM duty ratio dim signal DIM_pwm are high level, this moment, the base stage of the second triode Q12 was high potential and conducting, thereby the base stage of the first triode Q11 is also conducting of electronegative potential, the direct voltage of dc constant voltage power supply 300 output exports the base stage that drives triode Q21 in the constant-current driven module 120 to through the first triode Q11 and resistance and joint group 111, the base stage that drives triode Q21 is high potential and conducting, then the negative terminal of each street lamp bar is received ground through driving triode Q21 and sample resistance RS, the drive current that flows through the lamp bar produces voltage at sample resistance RS, at voltage that sample resistance RS produces after the 7th resistance R 7 and the 8th resistance R 8 dividing potential drops, drive the conducting degree of the first amplifying triode Q31, thereby control drives the conducting size of current of triode Q21.When the collector electrode that drives triode Q21 and the increase of the electric current between emitter △ Ice1, △ Ice1 is through the sampling of sample resistance RS, and be pressed in the electric current that produces △ Ibe2 between the base stage of the first amplifying triode Q31 and the emitter in 8 minutes through the 7th resistance R 7 and the 8th resistance R, namely the base stage of the first amplifying triode Q31 and the electric current between the emitter increase △ Ibe2, through the electric current amplification of the first amplifying triode Q31, at collector electrode and the increase of the electric current between the emitter △ Ice2 of the first amplifying triode Q31; Owing to the shunting action that increases the electric current of △ Ice2 between the collector electrode that is subjected to the first amplifying triode Q31 and the emitter, the current potential that drives the base stage of triode Q21 is dragged down, make the base stage and the electric current between the emitter that drive triode Q21 reduce △ Ibe1, through driving the electric current amplification of triode Q21, make and reduce △ Ice1 at the collector electrode and the electric current between the emitter that drive triode Q21, and then reduce △ Ibe2 at base stage and the electric current between the emitter of the first amplifying triode Q31, collector electrode and the electric current between the emitter at the first amplifying triode Q31 reduce △ Ice2, thereby drive the base stage of triode Q21 and the electric current between the emitter, electric current so forms the constant current output of lamp bar electric current based on stable between collector electrode and the emitter.Because the base stage of the driving triode Q21 in each driver element 122 all is connected with the base stage of driving triode Q21 in another driver element 122, therefore the driving of 122 pairs of connected lamp bars of each driver element and electric current adjustment realize the constant current adjustment to each street lamp bar all with reference to above-mentioned principle.
When the short circuit simultaneously of a short circuit or plurality of LEDs is arranged in the lamp bar; the voltage that produces at the negative terminal of lamp bar produces voltage by protection tube D3 in the 9th resistance R 9; when the voltage that produces in the 9th resistance R 9 surpasses the conducting voltage of voltage-stabiliser tube D2; voltage-stabiliser tube D2 conducting; the voltage that produces in the 9th resistance R 9 is after the dividing potential drop of the tenth resistance R 10 and the 11 resistance R 11; drive the 3rd triode Q13 conducting; the base stage of output over-voltage protection signal second triode Q12 to the drive control module 110; the base stage that is equivalent to the second triode Q12 is received ground; the current potential that is about to the base stage of the second triode Q12 drags down; the second triode Q12 ends; the direct voltage of dc constant voltage power supply 300 outputs is added in the base stage of the first triode Q11 through first resistance R 1; thereby the first triode Q11 ends; and then the direct voltage of dc constant voltage power supply 300 output can not export constant-current driven module 120 to by the first triode Q11 and resistance and joint group 111; namely cut off dc constant voltage power supply 300 to constant-current driven module 120 power supplies; reach the purpose that protection drives triode Q21, improve the reliability of circuit.
The utility model sends backlight signal BL_on by the master controller 200 on the TV motherboard after powering on; simulation dim signal DIM_analog and PWM duty ratio dim signal DIM_pwm; drive control module 110 is according to the backlight signal BL_on that receives; simulation dim signal DIM_analog and PWM duty ratio dim signal DIM_pwm; control dc constant voltage power supply 300 is to constant-current driven module 120 output dc voltages; the lamp bar that constant-current driven module 120 gets in the electric rear drive lamp bar module 400 is lighted; and adjust the electric current of each street lamp bar in the lamp bar module 400; make the electric current of every street lamp bar equate; realization drives the constant current of lamp bar; make circuit performance more stable; and; when in the lamp bar LED short circuit being arranged; by overvoltage protective module 130 to drive control module 110 output over-voltage protection signals; to cut off dc constant voltage power supply 300 to constant-current driven module 120 power supplies; protect the components and parts of circuit, improved the reliability of circuit.Simultaneously, the utility model LED constant-current drive circuit 100 is with respect to prior art, do not need by the Boost booster circuit input voltage to be boosted, the direct voltage that directly utilizes dc constant voltage power supply 300 to export is powered to drive the lamp bar for the lamp bar and is lighted, and has improved the EMI characteristic of circuit effectively.In addition, the utility model LED constant-current drive circuit 100 only adopts simple discrete component can realize the function of circuit, reduces cost effectively.
The utility model also proposes a kind of LED constant current driving device, this LED constant current driving device comprises master controller 200, dc constant voltage power supply 300, lamp bar module 400 and LED constant-current drive circuit 100, LED constant-current drive circuit 100 is connected with master controller 200, dc constant voltage power supply 300 and lamp bar module 400 respectively, the circuit structure of this LED constant-current drive circuit 100, operation principle and the beneficial effect that brings be consistent with above-described embodiment all, repeats no more herein.
The above only is preferred embodiment of the present utility model; be not so limit claim of the present utility model; every equivalent structure or equivalent flow process conversion that utilizes the utility model specification and accompanying drawing content to do; 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 present utility model.
Claims (9)
1. LED constant-current drive circuit, be connected with master controller, dc constant voltage power supply and lamp bar module respectively, it is characterized in that, comprise for the described dc constant voltage power supply of the control drive control module of whether powering, be used for driving the constant-current driven module that the lamp bar constant current of described lamp bar module is lighted, and be used for the output over-voltage protection signal to described drive control module, to cut off the overvoltage protective module of described dc constant voltage power supply output; Wherein:
The input of described drive control module is connected with described dc constant voltage power supply, and its control end is connected with described master controller, and its output is connected with the control end of described constant-current driven module; The input of described constant-current driven module is connected with the negative terminal of described lamp bar module, and the anode of described lamp bar module is connected with described dc constant voltage power supply; The input of described overvoltage protective module is connected with the negative terminal of described lamp bar module, and its output is connected with the control end of described drive control module.
2. LED constant-current drive circuit as claimed in claim 1, it is characterized in that, described drive control module comprises first triode, second triode, a diode, first resistance, second resistance, the 3rd resistance, the 4th resistance and resistance and joint group, and described resistance and joint group comprise a plurality of resistance parallel with one another; Wherein:
The emitter of described first triode is connected with described dc constant voltage power supply, the base stage of described first triode is connected with described dc constant voltage power supply through described first resistance, and be connected with the collector electrode of described second triode through described second resistance, the collector electrode of described first triode is connected with described constant-current driven module through described resistance and joint group; The base stage of described second triode is divided into three the tunnel behind described the 3rd resistance; the first via is connected with the simulation dim signal output of described master controller; the second the tunnel is connected with the PWM duty ratio dim signal output of described master controller; Third Road is connected with the backlight signal output of described master controller through described diode; the base stage of described second triode is connected with the output of described overvoltage protective module; and through described the 4th grounding through resistance, the grounded emitter of described second triode.
3. LED constant-current drive circuit as claimed in claim 2 is characterized in that, described drive control module also comprises the 5th resistance, the 6th resistance, first electric capacity, second electric capacity and the 3rd electric capacity; Described the 5th resistance is connected between described the 3rd resistance and the described simulation dim signal output, described the 6th resistance is connected between described the 3rd resistance and the described PWM duty ratio dim signal output, described first electric capacity is in parallel with described first resistance, described second electric capacity is in parallel with described the 4th resistance, and described resistance and joint group are through described the 3rd capacity earth.
4. LED constant-current drive circuit as claimed in claim 1 or 2, it is characterized in that, described constant-current driven module comprises amplifying unit and some driver elements, wherein a described driver element is connected with described amplifying unit, the corresponding connection of negative terminal of the street lamp bar in the input of each described driver element and the described lamp bar module, the control end of each described driver element is connected with the output of described drive control module.
5. LED constant-current drive circuit as claimed in claim 4 is characterized in that, each described driver element comprises that one drives triode and a sample resistance; The negative terminal of the street lamp bar in the collector electrode of described driving triode and the described lamp bar module is connected, the emitter of described driving triode is through described sample resistance ground connection, the base stage of described driving triode is connected with the output of described drive control module as the control end of described driver element.
6. LED constant-current drive circuit as claimed in claim 4 is characterized in that, described amplifying unit comprises first amplifying triode, the 7th resistance and the 8th resistance; The base stage of described first amplifying triode is connected with the emitter of described driving triode through described the 7th resistance, and through described the 8th grounding through resistance, the collector electrode of described first amplifying triode is connected with the base stage of described driving triode, the grounded emitter of described first amplifying triode.
7. LED constant-current drive circuit as claimed in claim 4 is characterized in that, described amplifying unit comprises first amplifying triode, second amplifying triode, the 7th resistance and the 8th resistance; The base stage of described first amplifying triode is connected with the emitter of described driving triode through described the 7th resistance, and through described the 8th grounding through resistance, the collector electrode of described first amplifying triode is connected with the base stage of described second amplifying triode, the grounded emitter of described first amplifying triode; The emitter of described second amplifying triode is connected with the base stage of described driving triode, the grounded collector of described second amplifying triode.
8. LED constant-current drive circuit as claimed in claim 1 is characterized in that, described overvoltage protective module comprises the 3rd triode, the 9th resistance, the tenth resistance, the 11 resistance, a voltage-stabiliser tube and some protection tubes; The negative terminal of the street lamp bar in the anode of each described protection tube and the described lamp bar module is connected; the negative electrode of each described protection tube is through described the 9th grounding through resistance; and be connected with an end of described the tenth resistance through described voltage-stabiliser tube; the other end of described the tenth resistance is connected with the base stage of described the 3rd triode; and through described the 11 grounding through resistance; the grounded emitter of described the 3rd triode, the collector electrode of described the 3rd triode is connected with the control end of described drive control module.
9. LED constant current driving device, comprise master controller, dc constant voltage power supply and lamp bar module, it is characterized in that, also comprise any described LED constant-current drive circuit in the claim 1 to 8, described LED constant-current drive circuit is connected with described master controller, described dc constant voltage power supply and described lamp bar module respectively.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201320091213 CN203136265U (en) | 2013-02-27 | 2013-02-27 | Circuit and device for LED constant current driving |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201320091213 CN203136265U (en) | 2013-02-27 | 2013-02-27 | Circuit and device for LED constant current driving |
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| CN203136265U true CN203136265U (en) | 2013-08-14 |
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| CN 201320091213 Expired - Fee Related CN203136265U (en) | 2013-02-27 | 2013-02-27 | Circuit and device for LED constant current driving |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104470060A (en) * | 2014-10-20 | 2015-03-25 | 深圳市华星光电技术有限公司 | Analog dimming conversion circuit and display device |
| CN105405410A (en) * | 2015-11-20 | 2016-03-16 | 青岛海信电器股份有限公司 | Backlight driving circuit and driving method and display device thereof |
| CN105864654A (en) * | 2016-06-07 | 2016-08-17 | 深圳市泓亚智慧科技股份有限公司 | Low-power-consumption cuttable constant-current LED lamp strip |
| CN108601155A (en) * | 2018-06-13 | 2018-09-28 | 上汽大众汽车有限公司 | A kind of automobile-used tail portion LOGO lamps light logic control circuit |
-
2013
- 2013-02-27 CN CN 201320091213 patent/CN203136265U/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104470060A (en) * | 2014-10-20 | 2015-03-25 | 深圳市华星光电技术有限公司 | Analog dimming conversion circuit and display device |
| CN105405410A (en) * | 2015-11-20 | 2016-03-16 | 青岛海信电器股份有限公司 | Backlight driving circuit and driving method and display device thereof |
| CN105864654A (en) * | 2016-06-07 | 2016-08-17 | 深圳市泓亚智慧科技股份有限公司 | Low-power-consumption cuttable constant-current LED lamp strip |
| CN108601155A (en) * | 2018-06-13 | 2018-09-28 | 上汽大众汽车有限公司 | A kind of automobile-used tail portion LOGO lamps light logic control circuit |
| CN108601155B (en) * | 2018-06-13 | 2023-06-06 | 上汽大众汽车有限公司 | Lighting logic control circuit of tail LOGO lamp for vehicle |
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