Single-phase ac light-emitting diode (LED) lamps require long-lifespan and high-efficiency ac-dc power converters for power factor correction (PFC) and current regulation. In such converters, the inherent double-line-frequency ripple power from the ac source is isolated from the load by large electrolytic capacitors (E-caps) or E-cap-less active circuits to improve reliability and lifespan. This paper presents an ac-dc LED driver with an additional active rectifier and a unidirectional auxiliary circuit for ripple power isolation. As compared with other similar designs, the proposed LED driver operates with reduced redundant power processing and a lower voltage on the storage capacitor, and the additional active circuits include fewer power components. The prototype with small polymer-hybrid capacitors and ceramic capacitors is separately tested in the experiment.
- AC-DC converters
- auxiliary circuit
- LED driver
- light-emitting diode (LED)
- power factor correction (PFC)
ASJC Scopus subject areas
- Electrical and Electronic Engineering