A single-switch ac-to-ac converters for driving ac loads which are particularly suitable for gas discharge lamp ballast applications based upon integration of automatic current shapers and converters that resemble a class-E converter, both parts sharing a single active switch. The first part comprises...http://www.google.de/patents/US6008589?utm_source=gb-gplus-sharePatent US6008589 - Single-switch, high power factor, ac-to-ac power converters
