| 摘要 |
Power for one or more luminaire accessories (26) is extracted from a series of lamp operating pulses provided by a phase angle dimmer (28). A DC power supply (44) is connected to the output (38, 40) of the dimmer (28) to develop and store DC accessory power. A lamp controller (48) is connected to the output (38, 40) of the dimmer (28) to transfer power from the lamp operating pulses to the lamp (24). The lamp controller (48) 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 (76) 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 (24) 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 (48). |
