High-pressure discharge lamp

High-pressure discharge lamps, having a sealed discharge vessel surrounded by a sealed glass envelope, are known in which an oxidizable metal foil (e.g. of molybdenum) is located, in the space between the vessel and the envelope substantial on the axis of the vessel and is electrically in series wit...

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Bibliographic Details
Main Authors OOSTVOGELS; FRANCISCUS M. P, MELIS; GUSTAAF, VAN LAARHOVEN; AIME P. A. M
Format Patent
LanguageEnglish
Published 11.11.1980
Subjects
BASIC ELECTRIC ELEMENTS
ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
ELECTRICITY
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Summary:High-pressure discharge lamps, having a sealed discharge vessel surrounded by a sealed glass envelope, are known in which an oxidizable metal foil (e.g. of molybdenum) is located, in the space between the vessel and the envelope substantial on the axis of the vessel and is electrically in series with the discharge path. If the envelope is fractured for any reason and the lamp is subsequently ignited, the temperature of the foil is increased due to the discharge current passing through it. The foil is oxidized, and hence fractured, by the air which has permeated said space and the lamp is, extinguished. Such oxidation and fracture normally takes about ten minutes. In accordance with the invention, the foil (14) in the space between the envelope (1) and vessel (2) is arranged close to the wall of the vessel adjacent to an electrode (6) so as to be heated mainly by heat generated in the vessel. This reduces the fracturing time to about one minute.
Bibliography:Application Number: US19780952369