Patent ID: 6181077
Filing Date: 2001-01-30
Classification: H05B,Y02B

Abstract:
An arc lamp power supply, the improvements comprising:a rectifier for converting alternating current utility power into direct current;a switch-mode controller providing a pair of gate drive signals according to a lamp-power output feedback signal and a current-level adjustment, and operating at a resonant frequency;a full-bridge resonant mode converter connected to receive said pair of gate drive signals and including four MOSFET power transistors in two parallel totem-pole circuits;a switch-mode transformer connected to be driven by said four MOSFET power transistors and having a center-tapped secondary output winding;a bridge rectifier connected to said secondary output winding of the switch-mode transformer and providing a direct current for an arc lamp to operate;a boost power supply connected to temporarily increase said direct current for an arc lamp to operate;an igniter connected to add high voltage initiation pulses to said direct current for an arc lamp to operate; anda safety interlock connected to bias said lamp-power output feedback signal such that the switch-mode controller can cancel said pair of gate drive signals, the safety interlock including an opto-isolator with an input that must receive a constant current for an output to release said bias and allow said lamp-power output feedback signal and the switch-mode controller to provide said pair of rate drive signals.