Powering LED Using High-Efficiency SR Flyback Converter

Abstract

A multifunction circuit is presented herein and applied to a synchronously rectified flyback converter, with the circuit not only playing the role of an <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LC</i> snubber but also detecting the zero crossing of the current to reduce switching loss and feeding the peripheral circuit. Hence, such a converter has high efficiency all over the operating range and, together with one front-end power-factor-correction ac-dc converter, is applied to feeding a LED streetlight. In this paper, the basic operating principles of the proposed topology are first illustrated in detail, and second, some simulated and experimental results are provided to demonstrate the effectiveness of the proposed topology.