GB314925A - Improvements in or relating to electric discharge tubes - Google Patents

Abstract

314,925. Dicker, S. G. S., (Naamlooze Vennootschap Philips' Gloeilampenfabrieken). April 2, 1928. Low-pressure metallic-vapour apparatus.-A discharge tube for rectifying multiphase currents of the kind having a solid incandescent oxide or other cathode and a filling of mercury vapour, with or without another gas such as argon, and liquid mercury, is furnished with one or more conducting members arranged between the anodes and the cathode and electrically connected to the anode. In the example shown in Fig. 1, the anodes 5 are located in arms 6 which carry, externally, strips 9 of metal foil, finelydivided carbon, or conducting paint. The strips may be disposed within the discharge tube and be connected to the anodes through condensers. The mercury may be contained in a reservoir 7 which communicates with the tube through a capillary orifice 8, or may be applied as a coating to the walls of the tube. The pressure of the mercury vapour may be regulated by heating or cooling means, e.g. by a heating element 10, the current through which may be regulated automatically. In a modification, Fig. 2, the conducting members 11 are arranged helically on the arms 12. The mercury reservoir 13 may be enclosed within the stem 14. A heating element 16 may be provided, the leading-in wires of which and those of the incandescent cathode may be led to contact pins fixed to a cap.