GB179568A - Improvements in electron discharge devices, especially for use in wireless communication - Google Patents

Abstract

179,568. Taggart, J. Scott-. Nov. 5, 1920. Addition to 166,260. Thermionic relays. - Relates to thermionic valves and valve circuits, of the kind described in the parent Specification, in which two anodes, a cathode, and a control electrode are employed, a rise of potential on the control electrode causing an increase of current to one anode and a decrease to the other, and consists (1) in amplifying-arrangements in which the input potentials are applied solely to the control electrode and (2) in amplifying or negative resistance circuits in which the input potentials are applied to the control electrode and the resulting changes in the anode-circuit current reacts on the control electrode. The valve as shown in Fig. 1 comprises two anodes A, B arranged on opposite sides of the cathode filament F, and a grid G controlling the electron current from the cathode F to the anode B. Both anodes are given a positive potential by batteries C, D, and an indicator I is placed in circuit with anode A. The control potential is applied to the grid G and varies the electron flow to the anode B, the current to the anode A being varied in the opposite sense. In the amplifier shown in Fig. 2, the grid G is connected through the input terminals J, H and battery E to a point between the indicator I and a resistance R in the A-anode circuit, both anode circuits being energized by a battery C<1>. An increase of potential applied to the grid G increases the B-anode current, and decreases the A-anode current. The voltage across resistance R decreases, and the grid G is thus made more positive, increasing the original effect on the indicator I. The change in voltage across the resistance R may be amplified before applying it to the grid G. In a modified arrangement, shown in Fig. 3, resistances R<1>, R<2> are placed in both anode circuits, and the output terminals Y, Z are connected to opposite ends of the resistances. Fig. 4 shows the valve arranged as a negative resistance for reducing the positive resistance of any circuit connected across the terminals K, L in the A-anode circuit. For producing oscillations, an oscillatory circuit is connected across the terminals K, L.