一种高可靠无源恒流LED驱动电源

Passive constant-current LED driver with high reliability

针对如何提高发光二极管(LED)驱动电源的使用寿命以及可靠性等问题,提出一种新型高可靠无源恒流LED驱动电源,并对其工作原理和性能特点进行了分析。由于该电源内部不含有电解电容,因此克服了由电解电容引起的LED驱动电源与LED理论使用寿命不匹配的问题。该电源内部不含有任何有源开关器件以及相关驱动、控制电路等,因此电路简单可靠。在工频交流电压输入时,其输出电流值近乎恒定,与所接负载LED串联颗数无关。最后,制作了一台220 V工频交流电压输入,输出电流平均值为350 mA,额定输出功率为42 W的试验样机,在负载LED颗数发生变化时,其输出电流识误差在10%以内,输入功率因数接近1,效率达到93.3%,实验结果验证了理论分析的正确性。

In order to improve the operating life and reliability of LED （Light Emitting Diode） driver, a passive constant-current LED driver with high reliability is proposed and its operational principle and properties are analyzed. Since there is no electrolytic capacitor in it,the mismatch between the theoretic life time of LED driver and the LED life time is avoided. Since there is no any active switching component,as well as the relevant driving and control circuits,the driver circuit is simple and reliable. Its output current is almost constant,immune to the number of LED. A prototype with 220 V AC input,350 mA output current and 42 W rated output power is built,and its output current error is below 10 % ,its input power factor about 1 and its efficiency up to 93.3 %. Experimental results verify the correctness of theoretical analysis.