Abstract:
The time required for an amalgam-regulated fluorescent lamp to stabilize and reach its rated light output under ''''cold-start'''' conditions is reduced by providing a small auxiliary body of amalgam on a selected portion of a metal conductor that is attached to one of the electrode structures within the lamp and is so arranged that it serves the dual function of a ''''failsafe'''' component. The auxiliary body of amalgam is so located with respect to the adjacent cathode that it is rapidly heated and releases mercury vapor as soon as the lamp is energized. The ''''fail-safe'''' conductor is preferably made of wire mesh or sheet metal and provides a conductive path from one of the leads to the stem which causes an arc to impinge upon and puncture the stem when the cathodes are devoid of emission material and the lamp has thus reached the end of its useful life.
Abstract:
The mercury vapor pressure within an operating fluorescent lamp or similar device is controlled by a quantity of mercuryamalgamative material that is retained at a predetermined location within the lamp by holding means secured to one of the mount assemblies or the lamp envelope. The amalgamative material preferably comprises indium and is held in place by a formaminous assembly. In the case of indium, the formed indium-mercury amalgam contains from about 80 to 95 atomic percent indium and both the lamp performance (light output versus ambient temperature) and amalgam retention are significantly improved with indium contents at the high end of the aforesaid atomic percent range. Various amalgam-holding structures, including temperature-compensating types employing bimetal elements, and a method of fabricating the vapor-pressure control components are also disclosed.