Incandescent tungsten filament halogen lamp - has filament at least partly coated with thermally decomposable metal bromide dissolved in volatile hydrocarbon

摘要

The lamp bulb is made of quartz glass borosilicate glass or a hard glass based on silica, and bromine circulates during operation. The bromine is produced by thermal decomposition of a solid metal bromide introduced into the envelope. The filament is coated at least in part with a metal bromide soluble in a volatile hydrocarbon. It decomposes at a temp. range between 300 degrees and 900 degrees C. The metallic bromide is pref. deposited from a solution of copper bromide and ethylene alcohol. The smallest spacing between the coated part of the filament and the point at which the current supply lead is introduced into the bulb is 20 mm.