Patent ID: 7551459

Claim:
A coupled inductor boost power converter, comprising, an input coupleable to a source of dc power, an output coupleable to a load, a first coupled inductor having a primary winding and a secondary winding, a second inductance connected in series with said first coupled inductor, a series network having a first terminal and a second terminal comprising a series connection of, a first capacitor, said secondary winding of said first coupled inductor, an active clamp network having a first terminal and a second terminal with said first terminal of said active clamp network coupled to said primary winding of said coupled inductor and with said second terminal of said active clamp network coupled to said input, comprising a series connection of, a second capacitor, and, first switch means, second switch means having a first terminal and a second terminal operable substantially in anti-synchronization to said first switch means with said first terminal of said second switch means coupled to said first terminal of said active clamp network and with said second terminal of said second switch means coupled to said input, third switch means having a first terminal and a second terminal operable substantially in anti-synchronization to said first switch means with said first terminal of said third switch means connected to said first terminal of said series network and with said second terminal of said third switch means connected to said output, fourth switch means having a first terminal and a second terminal operable substantially in anti-synchronization to said third switch means with said second terminal of said fourth switch means connected to said first terminal of said third switch means and with said first terminal of said fourth switch means connected to said output, whereby said second inductance provides energy to drive a zero voltage turn on switching transition for said second switch means.