GB494528A - Improvements in or relating to gas-filled electric discharge devices - Google Patents

Abstract

494,528. Discharge apparatus. SIEMENS & HALSKE AKT.-GES. April 28, 1937, Nos. 12132 and 12133. Convention dates, April 30, 1936 and Feb. 9, 1937. [Class 39 (i)] In a discontinuously controlled gas - filled electric discharge device having at least two control electrodes, these are so spaced relatively to the cathode and anode or anode system that the influence of the anode on the potential directly in front of the cathode is greater than the corresponding influence of either control grid alone. Thus the streams of electrons formed in the vessel flow practically entirely to the anode. The sum of the influences of all the control electrodes may be much greater than or may be less than that of the anode on the cathode. The desired effect may be obtained by using two control grids having bars 4, 6, Fig. 1, which are arranged in pairs and the openings between the pairs of which are made large. Alternatively, the control grid bars may be formed as helices, those of one grid being arranged within those of the other. In a modification, which may also be provided with an anode system, consisting of an anode 34, Fig. 5, and a grid 35 at cathode or other potential, and also with an incandescent or a mercury cathode, the control grids 32, 33 are provided with interfitting bars arranged to surround the discharge path. Alternatively, the grids may be in the form of helices fitting over within the other and also arranged to surround the discharge path. The length of the combined grids should not be more than twice the diameter of the discharge path.