Thomas P Loftus

US Patent:

47605120, Jul 26, 1988

Filed:

Jun 11, 1986

Appl. No.:

6/872802

Inventors:

Thomas P. Loftus - Newark NJ

Assignee:

American Telephone and Telegraph Company, AT&T Bell Laboratories - Murray Hill NJ

International Classification:

H02M 3335

US Classification:

363 20

Abstract:

A single ended forward converter includes a snubber/reset circuit that diverts current flow from the power switching transistor during the turn off transition to significantly reduce switching loss therein. This same circuit is further operative to resonate energy stored in the magnetizing inductance of the power transformer with a capacitor during a nonconducting period of the power switching transistor in order to reverse the polarity of current, in the magnetizing inductor and reset the core, and further obtain bipolar flux excursions in the transformer core during each cycle of operation.