GB257544A - Improvements in or relating to electric luminous discharge tubes - Google Patents

Abstract

257,544. General Electric Co., Ltd., (Patent-Treuhand-Ges. fiir Elektrische Gluhlampen). Jan. 28, 1926, [Convention date]. Vacuum tubes. - Azides of alkali or alkaline-earth metals are applied directly to one or both main electrodes of a lighting tube containing nitrogen, these electrodes being of such a size that under normal running conditions they are heated to a' temperature whereat slight decomposition of the azides occurs, say 200-300‹ C. in the case of sodium azide. As shown, a pocket b at the end of the tube a contains an iron electrode c in the form of a hollow cylinder, nearly filling the bore of the pocket. At the terminal end the electrode is fitted with a preferably conical receptacle f, containing the azide h and glass wool i. A cover g may be secured to the receptacle by a bayonetjoint. If the normal evolution of nitrogen is inadequate, the current increases and the glow spreads more deeply into the electrode so as more strongly to heat the receptacle f until normal working is restored. A fine hole may be made at the apex of the container f. Dimensions are given. The gas pressure is about 1 mm. mercury.