CN201742622U

CN201742622U - Constant-current control power supply for LED (light-emitting diode) street lamp

Info

Publication number: CN201742622U
Application number: CN 201020288850
Authority: CN
Inventors: 张健; 文金华
Original assignee: WUXI KEH ELECTRONICS CO Ltd
Current assignee: WUXI KEH ELECTRONICS CO Ltd
Priority date: 2010-08-12
Filing date: 2010-08-12
Publication date: 2011-02-09
Anticipated expiration: 2020-08-12

Abstract

The utility model relates to a constant-current source circuit of an LED (light-emitting diode) street lamp, belonging to a power circuit. Four paths of constant-current sources are connected in parallel to respectively supply power to four LED groups, and the composition of each constant-current source is as follows: after being sequentially connected, a surge and spike voltage suppression circuit, an EMC filter circuit, a full bridge rectification circuit, a PFC correcting circuit and a voltage reducing and stabilizing circuit are connected with a PWM output circuit, and constant voltage current needed by the LED is output through a current-expanding constant-current circuit. The LED constant-current power supply has the advantages of stable and reliable working and high brightness, and the damage of one LED group can not lead the entire lamp to go out, therefore, the constant-current control power supply can meet the requirement of the street lamp. Furthermore, the constant-current control power supply has the photosensitive dimming function, and can automatically adjust the brightness of the street lamp according to the illumination condition of environment, thereby better realizing energy conservation and prolonging the service life.

Description

The LED street lamp constant current control power supply

Technical field

The utility model relates to a kind of application circuit, particularly a kind of constant current control power supply that is used for the driving LED bulb.

Background technology

The construction in city needs a large amount of street lamps on the road now, and in order to adapt to the needs of saves energy, the LED street lamp has obtained using widely.The LED street lamp is because of the advantage of its luminous element, has that energy consumption is low, the life-span long, energy-conservation characteristics.

LED is different from common incandescent lamp, and its operate as normal needs the support of power circuit, so for the LED lamp, constant-current supply belongs to core component, a well behaved constant-current source is mixed high bright spot LED luminous tube, can save a large amount of electric energy.But the character of street lamp, determine it should have some special effects: power is big, illumination zone is wide, and control mode is flexible and changeable, long service life, not fragile or part have the leeway remedied when damaging etc.And present LED constant current control power supply all can not reach these effects.

The utility model content

At described these shortcomings of background technology, the purpose of this utility model is a kind of energy-conservation, cheap, multi-functional, high reliability of invention, be fit to the constant-current supply of the high-power requirement of street lamp.

The utility model is 4 road constant-current source parallel connections, give 4 groups of LED power supplies respectively, the composition of each road constant-current source is such: antisurge is with peak voltage circuit, EMC filter circuit, full bridge rectifier, PFC correcting circuit with after decompression voltage regulator is connected successively, connect the PWM output circuit, again through expanding the electric current of the required constant voltage of stream constant-current circuit output LED.

Described PWM output circuit, with control chip U1 is core, powered to U1 by voltage stabilizing circuit and electronic filtering step-down power supply circuit, photosensitive light adjusting circuit is connected to the signal input part EN end of control chip U1, and control chip U1 connects the CS end that peak detection circuit is input to control chip U1.

Described expansion stream constant-current circuit has high-low pressure metal-oxide-semiconductor Q1, Q2, fly-wheel diode and inductor rectifier to constitute, and expands on the DRV end of control chip U1 that the stream constant-current circuit is connected the PWM output circuit.

Described photosensitive light adjusting circuit is by photodiode, and the resistance formation, and resistance string is associated in EN end and the ground connection of control chip U1, and photodiode is connected in parallel between the vdd terminal and resistance of control chip U1.

Be connected with oscillating circuit on the TOFF end of the control chip U1 of described PWM output circuit, oscillating circuit is a capacity earth.

This LED constant-current supply, working stability is reliable, and the form of 4 groups of parallel connections can drive more LED lamp, the brightness height, one group of infringement can not cause extinguishing of whole lamp, more can adapt to the needs of street lamp.And, have photosensitive dimming function, can regulate output voltage automatically according to the light conditions of environment, regulate the brightness of street lamp, better realize energy-conservation and increase the service life.

Description of drawings

Fig. 1, embodiment circuit diagram of the present utility model.

Embodiment

This circuit is a kind of four tunnel parallel connection type constant-current sources independently, and it can drive the LED street lamp that 40W-100W does not wait, and expands current circuit 9 output stabling currents by constant current, drives the LED street lamp work of four tunnel same loads.

The circuit on each road, antisurge is with peak voltage circuit 1, EMC filter circuit 2, full bridge rectifier 3, PFC correcting circuit 4 with after decompression voltage regulator 5 is connected successively, connect PWM output circuit 8, again through expanding the electric current of the required constant voltage of stream constant-current circuit 9 output LED.

As the embodiment of Fig. 1,

Antisurge and peak voltage circuit 1: form by piezo-resistance RV, negative tempperature coefficient thermistor RT and short slowly fuse F1;

EMC filter circuit 2: form by inductance L 1, L2 and capacitor C 9, at ac power input end, generally need to increase the filter of forming by conjugation inductance, X electric capacity and Y electric capacity,, filter out conducted interference signal and radiated noise to increase the effect of the anti-EMI of entire circuit;

Full bridge rectifier 3: full-bridge rectifier diode D1-D4 mainly carries out the AC/DC conversion, therefore need give the safe clearance of 1.5 coefficients;

PFC correcting circuit 4: the electric current of exporting after the common bridge rectifier rectification is pulsating direct current, and electric current is discontinuous, and harmonic distortion is big, and power factor is low, therefore need increase passive power factor compensating circuit cheaply;

Lowering and stabilizing blood pressure 5,6.: this circuit bank will made through capacitor filtering by the diode voltage stabilizing;

Photosensitive light adjusting circuit 7: by photodiode D9, and two resistance R 11, R10 constitute;

PWM output circuit 8: by changing U1(9910) goes up the PWM operating frequency of exporting by the value of setting different capacitor C 7;

Expand stream constant-current circuit 9: under the effect of sustained diode 8, inductor rectifier L3, high-low pressure metal-oxide-semiconductor Q1, Q2 and current sense resistor, export a voltage, to riches all the way in LED street lamp light pipe energizing quantity at the constant electric current of certain limit.

During this circuit working, the electric main inlet is connected to fuse F1 and the antisurge negative tempperature coefficient thermistor RT of 1A.Be the EMI filter circuit afterwards, form by L1, L2 and C9.Diode D1-D4 is the rectification full-bridge, adopts 4 high pressure silicon diodes.C3, C4, R9, D5～D7 form passive power factor correcting circuit, satisfy the requirement of lamp power factor.PWM control chip U1 and MOS pipe Q1, Q2, ballast inductance L3, sustained diode 8 are formed the Buck decompression transformation, the CS end of control chip U1 connects peak detection circuit 12, gather the peak current on sensing resistor R5, R7, R8, the VR1, carry out constant current control by the pulse duty factor of internal logic control GATE pin signal.Control chip U1 by D10, the rectification of R4 current limliting after, after the electronic filter step-down that DZ2, C8 voltage regulation filtering form, power, this decompression voltage regulator can provide about 5.1V burning voltage, guarantees chip U1 steady operation in full voltage range.Capacitor C 7 is parts of chip oscillate circuit, is connected on the TOFF end of control chip U1, changes it and can regulate frequency of oscillation.Potentiometer VR1 is used for light modulation, but is used for finely tuning the electric current of constant-current source, makes circuit reach design power.D9 is a photodiode, effect is the brightness of regulating street lamp according to ambient lighting intensity, because this this street lamp constant-current supply has adopted 4 identical circuit parallel connections, for the fine adjusting street lamp brightness of energy under the situation that is implemented in different light, the parameter of divider resistance R10, R11 all has nothing in common with each other in four the road, selects for use according to actual operating position.The parameter of this circuit is 4 identical constant-current supplies of performance power, and load is the series connection of 20 white light LEDs, four groups of highlighted white light LEDs designs that drive 80 1W altogether, the electric current of every string is 320 milliamperes.The LED street lamp intensity of illumination of this 80W is equivalent to the effect of common 200W-300W street lamp, and therefore energy-conservation effect is very obvious.

Claims

1. LED constant current control power supply, it is characterized in that: by 4 road constant-current source parallel connections, give 4 groups of LED power supplies respectively, the composition of each road constant-current source is such: antisurge is with peak voltage circuit (1), EMC filter circuit (2), full bridge rectifier (3), PFC correcting circuit (4) with after voltage stabilizing reduction voltage circuit (5) is connected successively, connect PWM output circuit (8), again through expanding the electric current of the required constant voltage of stream constant-current circuit output LED.

2. LED constant current control power supply according to claim 1, it is characterized in that: described PWM output circuit, with control chip (U1) is core, give control chip (U1) power supply by voltage stabilizing circuit (5) and electronic filtering step-down power supply circuit (6), electronic filtering step-down power supply circuit (6) is connected to the vdd terminal of control chip (U1), photosensitive light adjusting circuit (7) connects the signal input part EN end of control chip (U1), and control chip (U1) connects the CS end that peak detection circuit is input to chip (U1).

3. LED constant current control power supply according to claim 1, it is characterized in that: described expansion stream constant-current circuit has high-low pressure mos pipe (Q1, Q2), fly-wheel diode (11) and inductor rectifier (10) to constitute, and expands to flow constant-current circuit and be connected on the DRV end of control chip (U1) of PWM output circuit.

4. LED constant current control power supply according to claim 2, it is characterized in that: described photosensitive light adjusting circuit (7) is by photodiode (D9), and resistance (R11, R10) constitutes, resistance (R10, R11) is connected on the EN end and the ground connection of control chip (U1), and photodiode (D9) is connected in parallel between the vdd terminal and resistance (R10) of control chip (U1).