A switched mode power supply has a sense transformer (TX2) with three windings. A first (primary) winding (WD) is in series with the primary winding (WP1) of the power transformer (TX1). Current regulation of the output is provided via a second (sense) winding (WS). Voltage regulation of the output is...http://www.google.com/patents/US4628429?utm_source=gb-gplus-sharePatent US4628429 - DC-DC converter with galvanically isolated feedback voltage regulation
