GB316175A - Improvements in or relating to glow discharge devices - Google Patents

Abstract

316,175. Westinghouse Lamp Co., (Assignees of Sinden, R. H.). July 24, 1928, [Convention date]. Vacuum tubes.-A glow-discharge device, for use as a sensitive relay, and in which the discharge occurs between cold electrodes in a gaseous filling, is provided with means for producing ultra-violet radiation within the envelope in a position such that it falls directly upon the anode, thus facilitating the establishment of a glow discharge between the anode-and the, relatively large cathode. In the construction shown, a main anode 3 is arranged within a large cylindrical cathode 2 and an auxiliary anode 4 is associated with a projection 9 from the cathode, forming a small gap across which the impressed voltage can readily produce a glow discharge. The gap is so placed that ultra-violet rays from the discharge fall directly upon the main anode 3 without any shielding, and by ionizing the gas around the anode or by causing electron emission from it start the main discharge between it and the cathode. The current of the main discharge may operate a relay 13, Fig. 1. The current in the auxiliary discharge may be kept very low by a resistance 15 and may be controlled by a thermostat 16. To reduce the starting and operating potentials an alkali or alkaline-earth metal or misch metal may be vaporized on to the cathode. The control anode 4 may have a head of 20 of thorium, titanium, uranium, &c., to reduce the starting potential still more, and the head 21 of the main anode 3 may be of iron, nickel, or misch metal. A filling of argon at a pressure of from 5 to 8 mm. may be used.