Extraction of accessory power from a signal supplied to a luminaire from a phase angle dimmer

摘要

Power for one or more luminaire accessories is extracted from a series of lamp operating pulses provided by a phase angle dimmer. A DC power supply is connected to the output of the dimmer to develop and store DC accessory power. A lamp controller is connected to the output of the dimmer to transfer power from the lamp operating pulses to the lamp. The lamp controller has a variable pulse transfer characteristic for providing lamp power without lamp performance degradation caused by accessory power variations. The variable pulse transfer characteristic can be implemented by a switching device that interrupts or blocks selected portions of the lamp operating pulses. The pulse transfer characteristic maintains constant apparent lamp brilliance independent of variations in accessory power requirements. In an off or in a preheat condition, power transfer to the lamp is reduced to prevent emission of a visible light beam. In a full brilliance condition, the lamp operating pulses are essentially unmodified by the lamp controller.