离线反激式LED恒流源的设计

Design of Off-line Flyback LED Constant Current Converter

LED是未来电光源的发展方向,民用普及化需要高效率低成本的恒流源驱动器。本文采用不连续导通模式(DCM)的工作原理,在正常工作时保持恒流输出,在负载断开时输出电压稳定在某个预设的最大输出电压上,从而保护了次级输出电路,实现了一款价廉、高效、安全的离线反激式恒流源驱动器。

LED is recognized as the next generation of lighting source. When it is faced with consumers, a high efficiency ＆ low cost constant current converter is usually demanded. Adopting discontinuous conduction mode （ DCM）, a prac- tical approach to the design of an off-line flyback constant current source is p cost, high efficient and electrically safe. The output current is held constant roposed in this article, which is low within the normal operating range. However, if the load is cut off, the output voltage will be held constant at the default maximum value. Thus the output stage on the secondary side is protected.