CN203596940U

CN203596940U - LED constant current source driver having power factor correction function

Info

Publication number: CN203596940U
Application number: CN201320622924.6U
Authority: CN
Inventors: 阴渤海
Original assignee: XI'AN HAICHAO ELECTROMECHANICAL TECHNOLOGY Co Ltd
Current assignee: XI'AN HAICHAO ELECTROMECHANICAL TECHNOLOGY Co Ltd
Priority date: 2013-10-10
Filing date: 2013-10-10
Publication date: 2014-05-14
Anticipated expiration: 2023-10-10

Abstract

The utility model provides an LED constant current source driver having a power factor correction function. AC current input by commercial power passes through a power supply conversion module, a power factor correction module, and a current control module sequentially, and at last the constant current output can be realized to drive an LED array. A balance half-bridge compensation circuit can be used for the power factor correction, the power factor of the driver can be improved effectively, and the power supply efficiency can be improved. The current control module can be used to provide a feedback signal by detecting the output current, and therefore the duty ratio of a PWM control signal can be adjusted according to the feedback signal, and the switching time of a CMOS power tube can be controlled. The charging and the discharging of a ballast inductor can be realized by adopting a freewheeling effect of a diode, and therefore the constant current can be provided for an LED load. By adopting the power factor correction function, the LED constant current source driver has rge better efficiency conversion effect and the better automatic adjusting performance by comparing with common circuits.

Description

With the LED constant-current source driver of power factor correction

Technical field

The utility model belongs to civil power input LED illumination driver, is specifically related to a kind of LED constant-current source driver with power factor correction.

Background technology

The internal characteristics of LED has determined that it is that optimal light source removes to replace traditional light source.First LED power consumption is very low, and electricity conversion is high, and under the condition of same brightness, LED consumes electric energy still less than ordinary lamps source, and the thermal radiation of LED is also greatly lower than ordinary light source.Under appropriate electric current and voltage, can reach 100,000 hours the useful life of LED.LED is made by nontoxic material, can pollute containing mercury unlike fluorescent lamp, and LED also can recycling simultaneously.Based on the various advantages of LED, LED has become the focus of lighting field at present, has large market potentiality.

Traditional LED driver is that constant voltage drives due to the electrology characteristic of LED, is applied to the little variation of voltage on LED and will causes the large variation of the electric current of flowing through on LED, and the easy like this LED that burns, so must be limited the electric current of LED.The mode often adopting is resistance series connection current limliting., when work, probably there is the unstable situation that LED is flickering in this resistance series connection current-limiting mode can not guarantee the to flow through current constant of LED.If electrical network is exported large voltage suddenly, exceed the safe range of the current limliting of series resistance, LED can be burnt.And the LED load series connection number that constant voltage driver connects must determine, driver can not be adjusted output voltage according to load LED series connection number automatically.Traditional constant-current source is not with power factor correction (PFC) module, therefore adopt after bridge rectifier, capacitor filter, can make AC input current produce serious wave distortion, inject a large amount of high order harmonic components to electrical network, therefore the power factor of net side is not high, only there is 0.6 left and right, and electrical network and other electric equipment are caused to serious harmonic pollution and interference.

Summary of the invention

The utility model is for fear of above deficiency, provide in one circuit structure simple, the current constant of LED can make to flow through, band power factor correction (PFC) module, can automatically adapt to load LED required voltage, simultaneously with low cost, good stability, the LED constant-flow driver that efficiency is high.

To realize like this for addressing the above problem the utility model :a kind of LED constant-current source driver with power factor correction, comprise power supply conversion module, power factor correction module, current control module, described power supply conversion module is made up of rectifier bridge (D31) and filter capacitor (C31), the alternating current of civil power input is converted into direct current by described rectifier bridge (D31), described filter capacitor (C31) is by the alternating component filtering after over commutation, and described power factor correction module is a kind of by three diodes, the balancing half-bridge compensation power factor correcting circuit of two electrochemical capacitors and a resistance composition, described current control module is a kind of by lowering and stabilizing blood pressure module (U31), bandgap voltage reference (U32), oscillator (T32), RS trigger (U33), with door (A31), comparator (U35), current sample module (U34), ballast inductance (L31), fly-wheel diode (D36), CMOS power tube (Q31), the circuit control device of electrolytic capacitor filter (C35) composition.

Preferred as one, described lowering and stabilizing blood pressure module (U31) comprises doubly holds formula ripple filter and linear low pressure pressurizer (U36), the described formula ripple filter that doubly holds comprises the first resistance (R32), the second resistance (R33), electric capacity (C34), voltage stabilizing didoe (D35) and transistor (T31), is connected an electric capacity (C34) and a voltage stabilizing didoe (D35) between described transistor (T31) base stage and ground.

Owing to having adopted such scheme, the relative generic drive of the utility model, has improved the stability of LED work, has extended the LED life-span, has improved the power factor of circuit, has reached energy-efficient, the effect of environmental protection.

Accompanying drawing explanation

Fig. 1: the utility model structure chart.

Fig. 2: current control module structure chart of the present utility model.

Fig. 3: balancing half-bridge compensation power factor correcting circuit figure of the present utility model.

Embodiment

Below in conjunction with accompanying drawing explanation, the utility model is described further.

As Fig. 1, the LED constant-current source driver of the utility model band power factor correction comprises power supply conversion module (1), power factor correction module (2), current control module (3).

Power supply conversion module (1) is made up of rectifier bridge (D31) and filter capacitor (C31), and civil power exchanges input and is converted into direct current by rectifier bridge (D31), then electric capacity (C31) after filtering, by the alternating component filtering after over commutation.

In power factor correction module (2), what use is balancing half-bridge compensation circuit, as shown in Figure 3, its structure is: the anode of electrochemical capacitor (C32) is connected with the negative electrode of diode (D32), the negative electrode of electrochemical capacitor (C32) is connected with the negative electrode of diode (D34), the anode of diode (D34) is connected with ground, the anode of diode (D33) is connected with the negative electrode of electrochemical capacitor (C32), the negative electrode of diode (D33) is connected with one end of resistance (R31), the anodic bonding of the other end of resistance (R31) and diode (D32), the anodic bonding of the anode of electrochemical capacitor (C33) and diode (D32), the negative electrode of electrochemical capacitor (C33) is connected with ground, one arm of electrochemical capacitor (C32) and diode (D34) composition half-bridge, another arm of electrochemical capacitor (C33) and diode (D32) composition half-bridge, diode (D33) and resistance (R31) composition charging connecting path, utilization is filled out paddy principle and is compensated, electrochemical capacitor (C33) and (C32) be in series.When the highest half that is charged to input voltage of the voltage on electric capacity, once line drop is to below input voltage half, diode (D34) and (D32) will be forward biased, make like this electric capacity (C33) and (C32) start parallel discharge, thereby adjust the angle of flow of input current, reached the effect of power factor correction.Resistance (R31) contributes to level and smooth input current spike, can also flow into electric capacity (C33) and electric current (C32) improves power factor by restriction.

Current control module (3) as shown in Fig. 2, comprise lowering and stabilizing blood pressure module (U31), bandgap voltage reference (U32), oscillator (T32), RS trigger (U33), with door (A31), a comparator (U35), current sample module (U34), ballast inductance (L31), fly-wheel diode (D36), CMOS power tube (Q31), electrolytic capacitor filter (C35); The input of lowering and stabilizing blood pressure module (U31) is connected with direct current input (U30), and output connects the input of bandgap voltage reference (U32) and the first input end with door (A31); The input in the same way of bandgap voltage reference (U32) output termination comparator (U35); The reverse input end of comparator (U35) is connected with the source electrode of CMOS power tube (Q31), and the output of comparator (U35) is connected with the R end of RS trigger (U33); The S end of RS trigger (U33) is connected with the output of oscillator (T32), and the output Q of RS trigger (U33) follows with the second input of door (A31) and is connected; Be connected with the grid of CMOS power tube (Q31) with door (A31) output; The anodic bonding of the drain electrode of CMOS power tube (Q31) and fly-wheel diode (D36), the source electrode of CMOS power tube (Q31) is connected with one end of current sample module (U34); The other end of current sample module (U34) is connected to the ground and connects; The anodic bonding of one end of ballast inductance (L31) and fly-wheel diode (D36), the other end is connected with the negative electrode of electrolytic capacitor filter (C35); The negative electrode of fly-wheel diode (D36) is connected with direct current input (U30); The anode of electrolytic capacitor filter (C35) is connected with the negative electrode of fly-wheel diode (D36), the anodic bonding of LED array (LED31) anode and electrolytic capacitor filter (C35), LED array (LED31) negative electrode is connected with the negative electrode of electrolytic capacitor filter (C35).

Shown in Fig. 1, described lowering and stabilizing blood pressure module (U31) comprises doubly holds formula ripple filter and linear low pressure pressurizer (U36), the described formula ripple filter that doubly holds is made up of the first resistance (R32), the second resistance (R33), electric capacity (C34), voltage stabilizing didoe (D35), transistor (T31), there is capacitance multiplication formula low pass filter and series voltage stabilizing adjuster double action, for current control module provides stabilizing low voltage accessory power supply.Between transistor T 31 base stages and ground, connect an electric capacity (C34), because base current only has 1/ (1+ β) of emitter current, be equivalent to connect one (1+ β) large electric capacity (C34) at emitter, connect again a voltage stabilizing didoe (D35) in base stage to ground, form exactly a series voltage regulator, this circuit can be eliminated HF switch ripple effectively, more stable by a linear low pressure pressurizer (U36) accessory power supply.

Described bandgap voltage reference (U32) produces reference voltage, the feedback voltage signal of returning with current sample module (U34) sampling compares by comparator (U35), the R end of comparator (U35) output access RS trigger (U33), oscillator (T32) clocking, the S end of access RS trigger (U34), produce PWM signal by RS trigger (U33), PWM signal is by the Q pin output of rest-set flip-flop (U33), the input of access and door (A31), with the switch driver of door (A31) as CMOS power tube (Q31), the grid of output access CMOS power tube (Q31), control the switch of CMOS power tube (Q31).In the time of the conducting of CMOS power tube, electric current flows through ballast inductance (L31), now, load is by the civil power input power supply after over commutation and power factor correction, give ballast inductance (L31) charging simultaneously, accumulation of energy effect is played in ballast inductance (L31), and now fly-wheel diode (D36) is in cut-off state; In the time that CMOS power tube turn-offs, fly-wheel diode (D36) conducting, ballast inductance (L31) releases energy, and by the afterflow effect of fly-wheel diode (D36), powers to the load.Electrolytic capacitor filter (C35) carries out filtering to output current, makes the waveform of output current milder.Current controller (3) is mainly the signal feeding back according to current sample module, adjust the pulsewidth of PWM signal, control CMOS power tube turn-on and turn-off time ratio, by the afterflow effect of fly-wheel diode (D36), make ballast inductance (L31) storage power and release energy, reaching the object of constant current output.

It is more than concrete exemplifying embodiment of the present utility model, output current scope reaches tens milliamperes to 1 peace, output voltage can be adjusted between 100V at 16V automatically according to load LED series connection number, circuit structure is simple simultaneously, transformation efficiency is high, and low production cost can be applied to various LED illuminations, LED signal lamp, the field such as liquid crystal display screen is backlight.

Claims

1. the LED constant-current source driver with power factor correction, it is characterized in that, comprise power supply conversion module, power factor correction module, current control module, described power supply conversion module comprises rectifier bridge (D31) and filter capacitor (C31), the alternating current of civil power input is converted into direct current by described rectifier bridge (D31), described filter capacitor (C31) is by the alternating component filtering after over commutation, and described power factor correction module is a kind of by three diodes, the balancing half-bridge compensation power factor correcting circuit of two electrochemical capacitors and a resistance composition, described current control module is a kind of by lowering and stabilizing blood pressure module (U31), bandgap voltage reference (U32), oscillator (T32), RS trigger (U33), with door (A31), comparator (U35), current sample module (U34), ballast inductance (L31), fly-wheel diode (D36), the circuit control device of CMOS power tube (Q31) and electrolytic capacitor filter (C35) composition.

2. LED constant-current source driver according to claim 1, it is characterized in that, described lowering and stabilizing blood pressure module (U31) comprises doubly holds formula ripple filter and linear low pressure pressurizer (U36), the described formula ripple filter that doubly holds comprises the first resistance (R32), the second resistance (R33), electric capacity (C34), voltage stabilizing didoe (D35) and transistor (T31), is connected an electric capacity (C34) and a voltage stabilizing didoe (D35) between described transistor (T31) base stage and ground.