GB189125A - Improvements in electron discharge devices and methods of operating same - Google Patents

Abstract

189,125. British Thomson - Houston Co., Ltd., (Assignees of Hull, A. W.). Nov. 12, 1921, [Convention date]. Vacuum apparatus, arrangements of; frequency, changing.-The cathode of a two electrode discharge device for use as an amplifier, rectifier, or as a generator of alternating current or high frequency oscillations, is adapted to pass a current of such strength that the strength of the magnetic field produced thereby is sufficient to control the passage of electrons between the cathode and anode. In the amplifier shown in Fig. 3, the cathode 8 is heated by current from a battery 18 on which alternating current is superposed by means of a transformer 19. The anode 14 is connected through a winding of the output transformer 23 and a source of continuous current 22 with the cathcde. During the interval when the magnetic field is a maximum, no current passes in the output circuit. During the lother intervals uni-directional flat-topped impulses pass through the output circuit. In a modification the cathode is heated by alternating current alone, and the frequency of the current produced is double that of the supply current. In the rectifying system shown in Fig. 4, the anodes A, A<1> of two valves 25, 26 are connected with the ends of the secondary winding of a supply transformer 27, the neutral point of the winding being connected through the load 29 with the cathodes C, C<1>. Current is supplied to the cathodes through two transformers 30, 31, and is interrupted alternately in each cathode by a rotating switch 33 driven by a motor 34 in synchronism with the supply current. During one half cycle the current through the cathode C<1> of one valve 26 is of such strength that the magnetic field stops the electron flow between the cathode C<1> and anode A<1>; during the other half cycle no current passes through the cathode but the temperature cf the cathode remains high enough to enable a current to pass through the valve. This arrangement may be used for producing the load by a source of unidirectional current.