Patent ID: 6259215
Filing Date: 2001-07-10
Classification: H05B,Y10S

Abstract:
An electronic high intensity discharge ballast for an illumination device comprising:(a) rectifying circuitry for rectifying an alternating current to a direct current;(b) power factor correction circuitry for boosting the voltage to be supplied to said illumination device;(c) a pair of MOSFET's for generating a square wave for filament preheating and powering said illumination device;(d) a programmable microprocessor for monitoring and controlling said power factor circuitry and said MOSFET's; and(e) dimming circuitry for controlling the amount of dimming by varying the operating frequency of the MOSFET's;wherein the microprocessor controls the MOSFET's to generate a first high frequency square wave for filament preheating followed by a second high frequency square wave for powering said illumination device.