The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 26, 1977
Filed:
Feb. 04, 1976
Avinash D Kulkarni, Montclair, NJ (US);
Ralph E Newton, Dover, NJ (US);
Westinghouse Electric Corporation, Pittsburgh, PA (US);
Abstract
The useful life of high-efficiency type bromine-tungsten cycle incandescent lamps, such as those used in TV-studio and theater lighting applications, is enhanced by dosing the lamps with a carefully controlled quantity of mercuric bromide (HgBr.sub.2) which dissociates when the filament of the finished lamp is energized and provides a predetermined amount of Br.sub.2 within the envelope during lamp operation. The quantity of HgBr.sub.2 dosed into the envelope is adjusted according to the design life and initial efficiency parameters of the specific lamp type so as to provide a concentration of Br.sub.2 within the envelope which is correlated with such parameters and prevents blackening of the envelope and premature failure of the filament at the particular 'life-efficiency level' of operation for which the lamp is designed. For a 1000 watt 120 volt tubular incandescent lamp (DXW type) having a design life of 150 hours and an efficiency of 28 LPW, the HgBr.sub.2 dosage is such that it provides from about 2.5 to 6 torr of Br.sub.2 within the lamp during operation -- whereas a lamp of the same wattage and voltage rating designed to operate for 50 hours at 33 LPW (DXN type) is dosed with a slightly larger quantity of HgBr.sub.2 to provide from about 3.5 to 8.5 torr of Br.sub.2 within the operating lamp.