A Novel Synchronous Current-Doubler Rectifier for LED Drivers Without Electrolytic Capacitors

摘要

High-brightness light-emitting diode (LED) lamps have attracted much attention because of their high efficiency, simple structure, energy conservation and environmental protection aspects, and long lifetime. Thus, an LED driver must have a long lifespan, high density, and compact space. However, conventional LED power supplies use an electrolytic capacitor as the storage capacitor in the holdup time, which has a short lifespan and occupies large space. In this paper, a novel synchronous current-doubler rectifier (SCDR) method is proposed as an LED driver. The reasonably designed circuit is used to control the output voltage ripple in the normal range without adding a complicated control circuit. The proposed topology is designed using few components, has no electrolytic capacitor, and has a low cost for high-output current LED driver applications. Circuit operating principles and detailed theoretical analysis are provided in this paper. A 200-W prototype has been established and tested, and the experimental results are presented to highlight the merits of the proposed circuit.