GB341061A - Improvements in and relating to glow discharge tubes for amplifying, detecting and generation of currents - Google Patents

Abstract

341,061. Discharge apparatus. SEIBT, G., 11, Hauptstrasse, and BLEY, H., 23, Bennigsenstrasse, both in Schoneberg, Berlin. Sept. 10, 1929, No. 27472. Convention date, Oct. 17, 1928. [Class 39 (i).] In a glow discharge tube for amplifying, detecting and generating currents, a glow discharge taking place between a cathode and an anode is used in place of a heated cathode and the electrons starting from the glow discharge and passing to a second anode, are acted upon by a controlling electrode, the first anode being constructed in the form of a plate. In Fig. 1, the glow discharge takes place between the cathode k and the first anode a<1>. Between the anode a<1> and a second anode a<2> a controlling grid r in the form of a frame is placed. The frame r may be replaced by a net-like member slightly larger than the plates a<1>, a<2> to give a larger amplification factor. In these arrangements electrons are drawn from the space between the cathode k and anode a<1> from the edges so that by constructing these plates and preferably also the plate a<2> as U-shaped members or providing a number of openings therein the edge effect may be increased. The controlling electrode may be a helical member surrounding the second anode a<2>. The discharge electrodes may be arranged as in Figs. 8, 9 so that the main discharge field is parallel to the anode a<2>. The system of electrodes s, a<2> may be duplicated in the arrangement according to Fig. 8 as well as in that shown in Fig. 9. Fig. 5 shows the connections which may be employed. A voltage source n of about 220 volts is shunted by a potentiometer P. The negative terminal is connected to the cathode k and the anodes a<1>, a<2> are connected respectively to a tapping p<1> at about 200 volts and a tapping p<3> at about 210 volts. A telephone L is connected in the circuit of anode a<2> and the lead to the controlling electrode which is tapped at a point p<2> which is negative with respect to p<1> contains the secondary of a transformer t, the primary of which receives the current to be amplified. The anode a<2> may have a positive potential of only 1 volt and the controlling electrode a negative bias of 1-2 volts with respect to the anode a<1>. The gas in the tube which is preferably neon at about 6 mms. pressure should be as pure as possible and free from mercury. The mesh of the controlling grid s should not be too small, but should be 4 mms. or more. The leads to the electrodes are surrounded by insulating material e.g. glass tubes to avoid direct discharges between them. The invention is particularly applicable in connection with mains-operated radio receiving sets.