A dc-ac converter capable of supplying a finely regulated ac drive voltage to a load is provided. For this purpose, the converter includes, in a primary winding of a transformer, a full-bridge or half-bridge type semiconductor switch circuit whose switch can be controlled by pulse-width modulation. Transformer...http://www.google.de/patents/US7835161?utm_source=gb-gplus-sharePatent US7835161 - DC-AC converter and method of supplying AC power
