A SEPIC-energy-regenerative-snubber with linear current regulator for power LEDs

Abstract

This paper presents an AC electronic lighting system using a non-isolated SEPIC PFC rectifier to drive and control power LEDs currents. One energy regenerative snubber for reducing the converter switching losses and improve the system efficiency is proposed. To reduce ripple current in the LEDs array a linear current regulator is placed in the SEPIC's output terminals. In order to reduce the efficiency impairment, the conditions for achieving minimum energy loss in the current regulator are also detailed. The main equations of the proposed energy regenerative snubber as well as the experimental results of a prototype that feeds 35 LEDs / 42 W are presented. In this paper, the system operates with 127 Volts of input voltage and the point of minimum energy loss in the linear regulator is adjusted in open loop to validate the converter operation.