Abstracto

Design and Implementation of Asymmetrical Half Bridge Converter for LED Drivers

P.Aswini, Mrs. K.S.Pavithra

This paper presents a high reliability and high efficiency light-emitting diodes for low power application. An AC-DC converter is a common converter topology approach for low voltage application. The prefect option for this approach is a Asymmetrical Half Bridge converter it has high efficiency constant switching frequency operation and small output filter. Asymmetrical Half Bridge is a perfect candidate for SD-SR because the transformer do not have dead times. Another main issue is its closed-loop controller does not be very fast, it will also cancel the previously shown low frequency ripple. A technique used to reduce the output voltage ripple is feed forward technique. The proposed method is an average current mode control technique gives low frequency ripple in the output voltage. Also a related problem to the AHB is overcome by proposed technique. The results obtained with a 60w topology gives efficiency of AHB as 94%. Index Terms- AC-DC converter, asymmetrical half bridge (AHB), self-driven synchronous rectification (SD-SR), LED drivers