Sulfur lamp
The sulfur lamp is a microwave-powered electrodeless lighting system conceived by engineer Michael Ury, physicist Charles Wood and their colleagues in 1990 and further developed in 1994 by Fusion Lighting (USA), with support from the U.S. Department of Energy. About the size of a golf ball, the sulfur lamp consists of a quartz bulb containing non-toxic sulfur and inert argon gas at the end of a thin glass stick. A microwave energy source of 2.45 GHz (magnetron) bombards the lamp while a fan-cooled motor spins the lamp at 3400 rpm. The microwave energy excites the gas, which heats the sulfur, forming a brightly glowing plasma that can illuminate a very large area. The first prototype lamps were 5.9 Kw units with a system efficacy of 80 lumens per watt. Correlated color temperature was about 6000K with a color rendering index of 79 CRI. The sulfur lamp starts within seconds even at low ambient temperatures and can be dimmed. The lamp emits no electric or magnetic fields, and the light output remains constant over its life. The energy output is continuous throughout the visible spectrum (much like sunlight), however the source is low in both the ultraviolet and infrared energy. The design life of the lamp is currently approximately 60,000 hours, however the design life of the magnetron is currently only about 15,000-20,000 hours. Fusion Lighting closed its doors in early 2002 after using up about $90 million in venture capital, and currently the field of sulfur lighting is essentially dead.
|
|
