Either a two-switch, double-diode boost converter, or simply a revised design of your current converter to remove the input bridge and have something far more efficient in its place.
Worried about Common Mode noise ? don't be - real solutions exist that can be integrated easily without requiring extra pcb real estate.
All the practical problems have been solved !
So where high efficiency or compactness is a priority, contact us for a technology transfer
We have used standard UPF control IC's like the UC3854N, UCC3817D to control the two switch booster from 90VAC to 275VAC with our novel current extraction technique.
Updated October 20, 2011