Boost Integrated Flyback AC-DC Converter with Valley Fill Circuit for LED Light Bulb

Abstract

In this paper, the boost integrated flyback converter derived AC-DC converter for the indoor Light Emitting Diode (LED) lamp application is proposed. The valley fill circuit is employed in the boost integrated flyback converter, which reduces voltage stress of storage capacitor. Under universal input voltage operation, the 120Hz output current ripple caused by the input line voltage is reduced through applying the valley fill circuit. The detailed features of the converter are analyzed. The prototype of 6W/24V AC-DC converter for indoor LED lamp application is implemented. The experimental results verify the reduction of 120Hz current ripple and high power factor (PF) in indoor LED drive system.