In a power-line-operated power-factor-corrected electronic ballast, a pair of series-connected fluorescent lamps is powered via a tuned L-C circuit that is series-excited by the rectangular-wave 33 kHz voltage output of a half-bridge inverter and parallel-loaded by the fluorescent lamps. Power factor...http://www.google.es/patents/US5103139?utm_source=gb-gplus-sharePatente US5103139 - Lamp starting and operating procedure in electronic ballast
Lamp starting and operating procedure in electronic ballast
