Mathematical Problems in Engineering
Volume 2012 (2012), Article ID 593568, 17 pages
Research Article

Single-Stage Coupled-Inductor Sepic-Type HB-LED Driver with Soft Switching for Universal Line Input

1Department of Electronic Engineering, National Kaohsiung First University of Science and Technology, Kaohsiung City 811, Taiwan
2Department of Electrical Engineering, Far East University, Tainan City 744, Taiwan

Received 5 January 2012; Revised 20 May 2012; Accepted 20 May 2012

Academic Editor: Ricardo Femat

Copyright © 2012 Chih-Lung Shen and Kuo-Kuang Chen. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


This paper proposes a single-stage Sepic-type high brightness LED driver for universal line input to perform power factor correcting and LED dimming. In the driver, a coupled inductor is introduced to replace with two separate inductors to lower volume and cost. A soft-switching cell is embedded into the driver to obtain zero-voltage switching (ZVS) feature so as to furthermore improve driver efficiency. Mathematical derivation and detailed discussion is presented. A prototype is designed, analyzed and implemented, which demonstrates the feasibility of the driver and verifies the theoretical analysis.