METHOD AND APPARATUS FOR DIMMING HIGH INTENSITY DISCHARGE LAMPS

摘要

A method for operating a HID lamp (400) using a bi-power electromagnetic ballast. The method includes applying a full power level to the lamp to produce full brightness (402) and applying a dimmed power level (404) to the lamp to produce a dimmed brightness. The lamp may be dimmed by switching the lamp power from the full power level to the dimmed power level (406) and then applying a full power pulse to the lamp (408). The dimmed power level is less than the full power level. A bi-power electromagnetic ballast which is adapted to operate according to the above mentioned method is also described.