GB248739A - Improvements in electron discharge apparatus - Google Patents

Abstract

248,739. British Thomson-Houston Co., Ltd., (Assignees of Warner, J. C.). March 5, 1925, [Convention date]. Thermionic generators.-In order to reduce internal losses in a thermionic oscillator of the four-electrode type, the potential applied to the spacecharge grid is caused to vary rhythmically with the current pressure through an oscillatory current associated with the anode and control-electrodes instead of remaining at a constant positive potential value. As shown in Fig. 1, the main oscillatory circuit comprises inductances 6, 7 and capacities 8, 9 connected between the plate 3 and the usual control grid 4. A coil 11 connects the space-change grid 5 to the cathode 2 and is variably coupled to the inductance 6. In this way a positive charge is induced on the grid 5 when maximum current is flowing, tending to reduce the plate impedance. When the current is low, the space-charge grid becomes negative and does not absorb any power. A signalling key 17 may be inserted in the circuit of the space-charge grid as shown. The positions of the two grids 4, 5 relative to the cathode may be interchanged. The load circuit 10 mav constitute the main oscillatory circuit and be coupled to the plate and to both of the grid circuits.