GB310049A - - Google Patents

Abstract

310,049. Dubilier Condenser Co. (1925), Ltd., (Assignees of Linke, J.). April 20, 1928, [Convention date]. Void [Published under Sect. 91 of the Acts]. Vacuum tubes; low-pressure metallic-vapour apparatus.-To diminish the potential drop in thermionic valves, a filling of gas or mercury vapour or both is introduced and either (1) a main discharge is produced between an anode C and and incandescent cathode B, while the telephone or its equivalent is connected to an auxiliary anode E associated with a control grid D, as shown in Figs. 3, 5, and 6, or (2) a rod R, Fig. 4, of vaporizable material is associated with the cathode B to form a conductive path between the anode and the cathode. In the first construction the discharge from the anode C may be prevented from clinging to the grid D by a screen F, which may be of insulating material or of conductive material adapted to be connected to a source of potential. To provide a filling of mercury vapour, one end of the cathode may connect with a mercury pool G, Fig. 5. In the construction shown in Fig. 6, the anode E is of annular form and is enclosed by the grid D, the lead to the anode C is covered with insulating material K, and a vaporizable rod R is inserted in the cathode. The cathode filament may have a high heat inertia so that it may be heated by alternating current. The grid may be in the form of an internal or external magnet coil through which the current flows.