CN201418184Y

CN201418184Y - Constant-current driving power for high-power LED

Info

Publication number: CN201418184Y
Application number: CN2009201266276U
Authority: CN
Inventors: 任启秀; 邓波; 王勇; 张布林
Original assignee: Chongqing Qiaoya Electronic Co Ltd
Current assignee: Chongqing Qiaoya Electronic Co Ltd
Priority date: 2009-03-13
Filing date: 2009-03-13
Publication date: 2010-03-03
Anticipated expiration: 2019-03-13

Abstract

A constant-current driving power for a high-power LED comprises an EMI filtering circuit, a rectification circuit, a driving circuit and a controlling circuit. The controlling circuit comprises a multiplier, an MOSFET power tube, a shaping network, an oscillator, control logic and a current-sense amplifier. The driving power has the advantages that the power factor of the line is higher than 0.99,the transmission of the idle work is reduced, the availability of the electric energy of the power supply transmitting system is improved, the total harmonic wave content of the input current is lower than 10 percent, the contamination to power network is controlled efficiently to ensure that the power and electronic equipment can work normally in a high-efficiency manner, and possible damage andaging influence to the equipment can be reduced through the reasonable circuit design; and the driving power is suitable for various LED lamps with high power, and has good popularization value.

Description

The great power LED constant-current driving power supply

Technical field

The utility model relates to the improvement technology of LED driving power, is specifically related to a kind of great power LED constant-current driving power supply.

Background technology

LED has advantages such as environmental protection, energy-conservation, life-span be long and is regarded as the 21 century lighting source, has now begun to replace conventional light source and has widely applied on various lightings.But, can increase and raise gradually by number when use because LED itself has operating current, cause the LED bulb to present the characteristic of scintillation because of the switched power supplier output current is not enough at last, determined it not adopt same driving power, thereby in order to avoid voltage fluctuation cause the electric current increase that LED is damaged with ordinary incandescent lamp.

Yet, existing various LED driving power performance is unsatisfactory, all is usually to adopt the low pressure constant voltage, and basic structure has following two kinds: a kind of is the voltage stabilizing circuit that is provided with transforming circuit and joins with it, but the unnecessary energy of meeting elimination causes energy pollution in the process of transformation, voltage stabilizing; Another kind then is a high frequency switch power, can produce multiple harmonic and electrical network is polluted.As traditional non-control rectification driving power, because input impedance is capacitive, there is big phase difference between input voltage and input current, add that input current is serious non-sine, and be pulse type, and cause the circuit harmonizing wave composition very big, power factor is extremely low, usually have only about 0.65, the utilization rate of electrical of whole electric power system is very low.Particularly developing rapidly of various power electronic equipments makes the harmonic pollution of utility network be on the rise in recent years, various faults that caused by harmonic wave and accident also constantly take place, and the root that causes equipment fault also may be because the harmonic effects of adjacent factory generation produces to public distribution network.Produced additional harmonic loss as the components and parts in utility network, reduced the efficient of generating, transmission of electricity and power consumption equipment, 3 a large amount of subharmonic can make the overheated even breaking out of fire of circuit when flowing through the neutral line; Harmonic wave also can produce mechanical oscillation, noise and overvoltage, makes the transformer part seriously overheated, makes apparatus overheat, ageing of insulation, the losts of life such as capacitor, cable, so that damage; Also can produce contiguous communication system and disturb, the lighter produces noise, reduces communication quality, and weight person causes loss of data, makes the communication system can't operate as normal.The seriousness of harmonic wave harm has caused the concern of people's height.

The utility model content

Adopt traditional non-control rectification driving power at LED lamp of the prior art, there is big phase difference between input voltage and input current, the serious non-sine of input current, cause harmonic effects serious, the deficiency that power factor is extremely low, the purpose of this utility model provides a kind of power factor and utilization rate of electrical that can improve power supply greatly, reduces the harmonic pollution of power electronic equipment, great power LED constant-current driving power supply applied widely.

The purpose of this utility model is achieved in that a kind of great power LED constant-current driving power supply, is made up of EMI filter circuit, rectification circuit, drive circuit and control circuit; Control circuit is controlled output voltage and electric current by its internal components.

Further feature, described control circuit comprises multiplier, MOSFET power tube, shaping network, oscillator, control logic and current sense amplifier.

Described control circuit adopts the L6562 chip to control special chip as power factor compensation.

With respect to prior art, the utlity model has following remarkable advantage:

1, by reasonable circuit design, the power factor that makes circuit has reduced the transmission of idle work greater than 0.99, has improved the utilance of power transmission system electric energy;

2, make the input current total harmonic distortion be lower than 10%, effectively controlled the pollution of harmonic wave, make the power electronic equipment can high efficiency operate as normal, reduced the device damage and the aging influence that may cause electrical network;

3, the efficient height, cost is low, the scope of application is wide, is suitable for various high-powered LED lamps, has excellent generalization values.

Description of drawings

Fig. 1 is the functional-block diagram of the utility model great power LED constant-current driving power supply;

Fig. 2 is a kind of circuit theory diagrams of embodiment.

Among the figure, 1-EMI filter circuit, 2-rectification circuit, 3-drive circuit, 4-control circuit.

Embodiment

The utility model is described in further detail below in conjunction with the drawings and specific embodiments.

Great power LED constant-current driving power supply of the present utility model as shown in Figure 1, is characterized in that, is made up of EMI filter circuit 1, rectification circuit 2, drive circuit 3 and control circuit 4; Control circuit 4 is controlled output voltage and electric current by its internal components.EMI filter circuit 1, rectification circuit 2 and drive circuit 3 belong to prior art, and the high-frequency impulse of the extraneous electrical network of EMI filter circuit 1 filtering reduces Switching Power Supply electromagnetic interference to external world itself simultaneously to the interference of power supply.Rectification circuit 2 carries out the AC/DC conversion with the alternating current of input.Drive circuit 3 is converted to constant-current supply with alternating voltage, and finishes the coupling with the LED voltage and current simultaneously.

Described control circuit 4 comprises multiplier, MOSFET power tube, shaping network, oscillator, control logic and current sense amplifier.

Described control circuit 4 adopts the L6562 chip to control special chip as power factor compensation.

Operation principle: referring to Fig. 2, the input alternating voltage is behind bridge rectifier, and the half-sinusoid dc pulse moving voltage of output 100Hz is through the resitstance voltage divider dividing potential drop, at R ₇On sampling voltage through little capacitor C ₇Filter away high frequency noise, and be input to the multiplier of chip internal.Filter capacitor EC ₁The two ends direct voltage passes through R ₁₁, R ₁₂And R ₁₃Dividing potential drop is input to the end of oppisite phase of chip internal error amplifier, and compares with the accurate reference voltage of error amplifier in-phase end, produces the error signal of an output dc voltage, as another road input of one-quadrant multiplier.When ac input voltage when zero changes to peak value by sinusoidal rule, the thresholding of the output Control current sense comparator of multiplier forces by MOSFET power tube Q ₁Peak current follow the tracks of the variation track of ac input voltage.Flow through MOSFET power tube Q ₁Electric current in resistance R ₁₁On be converted to voltage signal, be input to the positive input of current sense comparator in the L6562 chip.The waveform of transformer T electric current is high frequency sawtooth triangular wave, increases from zero in the process of peak value Q at current value ₁It is conducting.The output of multiplier then is the reference voltage of inductance peak current, as long as at R ₁₁On sensing voltage surpass the threshold voltage of current sense comparator, logical circuit action in the sheet, output mos FET power tube cut-off signals.

The secondary winding of transformer T with induced voltage through D ₁Rectification C ₁Filtering is as the accessory power supply behind the L6562 chip enable; The secondary winding also is used as the highly sensitive current sensor of T.After the secondary winding being flow through the current detecting of T, through current-limiting resistance R ₁₀Be input to zero current detector in the sheet, as long as inductive current is reduced to set " zero " level of chip, zero current detector is then by set door lock driven MOS FET conducting.Owing to dropped to before zero at inductive current, MOSFET can conducting, and in its conduction period, booster diode then ends always, so to the rectifier diode D that boosts ₃To require be not very harsh reverse recovery time.

The current control mode of power factor compensation control special chip L6562 is the peak current control mode.Adopt a sinusoid fiducial electric current as the upper limit, the detection signal that amplifies back and input all-wave voltage through error by the output detection signal acquisition of multiplying each other, lower limit then is zero.Detailed process is to compare with the sinusoid fiducial electric current by the sense switch electric current, stopcock when reaching this reference current, and open-minded once more when inductive current is zero, this control makes that inductive current is the critical current operating state.The sense switch pipe flows through electric current, the gained voltage signal is sent into the zero current comparator of L6562 inside.This comparator currents fiducial value is supplied with by multiplier output.Multiplier has two inputs, and one is the error signal between converter output voltage and the reference voltage; Another is output voltage sampled value after the full-wave rectification.Therefore, current reference is two half-wave sinusoidal voltages, makes the waveform of this input voltage of peak envelope line following of inductive current, makes input current and input voltage same-phase, and near sinusoidal.When output voltage rose, output voltage error amplifier descended, and the reference current value of multiplier output is descended, and the ON time of switching tube shortens, and the electric current that flows through inductance descends, thereby output voltage is descended.Otherwise, output voltage is risen, to reach the purpose of regulated output voltage.Because multiplier input sampling is from the output of full-bridge rectification, so the output of multiplier is identical with the phase place of full-bridge rectification output voltage waveforms, thereby make the mean value and the rectifier output voltage homophase of inductive current, reach the purpose of power factor compensation.

Claims

1, a kind of great power LED constant-current driving power supply is characterized in that, is made up of EMI filter circuit (1), rectification circuit (2), drive circuit (3) and control circuit (4); Described EMI filter circuit (1), rectification circuit (2) and drive circuit (3) are connected successively, and the control end of control circuit (4) connects the control end of rectification circuit (2) and drive circuit (3) respectively, and described control circuit (4) adopts the L6562 chip.