Electronic ballasts with current and voltage feedback paths

摘要

A power converter for providing high frequency current to a load such as a fluorescent lamp. A rectifier circuit provides DC power to a half-bridge inverter whose output is connected to one end of a resonant load circuit. One load connection is at the other end of the load circuit, and is connected to one AC-side terminal of the rectifier circuit to provide current feedback. A voltage feedback capacitor is connected between the other AC-side rectifier circuit terminal and the other load connection. The two feedback paths contribute equivalent components to charging current for a bulk capacitor for the DC power to the inverter. Excellent fluorescent lamp ballast performance is obtained with constant inverter frequency, and with either full bridge or voltage doubler embodiments.