原边控制带TRIAC调光的LED驱动电源的设计

摘要

The TRIAC dimmer is a most popular dimmer at present. To solve the problems such as flicker, the narrow dimmable range and low efficiency with TRIAC controller of LED lighting system, an LED driver with primary constant control and TRIAC dimming function based on the chip FL7730 is proposed. In the circuit, a passive discharge circuit is given to provide the hold current and latching current for TRIAC,and an active damper circuit to suppress the spike voltage when the dimmer turns on. As is verified through the experiment, the power factor of the dimming driver is higher than 0. 9,the efficiency is over 0. 8,and flicker-free dimming is implement.%三端双向可控硅( TRIAC)调光器是目前应用最为广泛的调光器。针对TRIAC调光过程出现的闪烁、调光范围小、效率低等问题,基于FL7730芯片设计一款基于TRIAC调光的原边恒流控制的LED驱动电路；在电路中设计无源泄放电路为TRIAC提供维持电流和擎住电流,避免TRIAC误触发；设计有源阻尼电路抑制调光器导通时产生的尖峰电压。实验结果表明,调光驱动电源的功率因数高于0.9,效率在0.8以上,实现无闪烁调光。