GB220620A - Improvements in or relating to electric discharge tubes - Google Patents

Abstract

220,620. Naamlooze Vennootschap Philips' Gloeilampenfabrieken. Aug. 14, 1923, [Convention date]. Vacuum tubes.-In order to facilitate the removal of occluded gas from an electrode in a tube which is continuously or temporarily filled with gas, one or more auxiliary electrodes are arranged in proximity to the electrode, or the electrode may consist of insulated parts, so that a gaseous discharge may be passed between the auxiliary and main electrodes or between the parts of the main electrode; the auxiliary electrode is inoperative during normal working. The arrangement is applicable, to tubes in which the electrodes are spaced widely apart as in Moore tubes. The areas of the main and auxiliary electrodes should be approximately equal. In the Moore tube shown in Fig. 1. the electrode at one end of the tube 2 consists of semi-cylindrical parts 3, 4 with separate leads 5, 6. A discharge is passed between the parts in a filling for instance of argon at a pressure of 10 mm. of mercury, and the fining and liberated gas are removed; the operation may be repeated several times. During normal working the parts 3, 4 act as a single electrode. In a rectifying tube a straight incandescent wire cathode is surrounded by an anode consisting of two parts shaped as shown in Fig. 1. In another arrangement a cylindrical main electrode is surrounded by a cylindrical auxiliary electrode, or conversely, and during working one only of the electrodes is operative.