Electronic ballast with crest factor control

摘要

A self-oscillating half-bridge inverter is powered from a power-line-operated rectifier means providing a DC supply voltage having a relatively high crest-factor. The inverter is loaded by way of a series-tuned high-Q LC circuit connected across this DC voltage. A pair of fluorescent lamps is series-connected across the tank-capacitor of the LC circuit. Also connected across the DC voltage is an arrangement of three energy-storing capacitors charged in series and discharged in parallel. The crest-factor of the current flowing through the fluorescent lamps is substantially lower than the crest-factor of the DC supply voltage.