GB696718A - Improvements in and relating to excitation and control systems for electronic devices - Google Patents

Abstract

696,718. Converting. BRITISH THOMSONHOUSTON CO., Ltd. July 9, 1951 [July 22, 1950], No. 16232/51. Class 38 (ii). A control system for an ignitron 1 having a holding anode 4 and a control grid 3, in addition to the usual igniter 6 and main anode 2, comprises valves 19 controlling, respectively, the igniter and grid potentials, the grids of the valves being fed in push-pull with a peaky control signal S which causes the valves to conduct alternately and effect alternate conduction of further valves IFT, GFT in the igniter and grid circuit, respectively, of the ignitron. The arrangement is such that upon conduction of valve IFT a condenser IFC (previously charged from a source 8) discharges through the igniter 6 and initiates ionization within the ignitron; ionization is then maintained by the holding anode, which is connected to a source 12, but negative bias on the control grid prevents conduction to the main anode. When valve GFT conducts (later in the signal cycle) the grid bias is overcome by an opposing voltage from a source 14 and the discharge passes to the main anode 2. To prevent application of the " opposing " grid voltage in event of anode 4 failing to hold the initial discharge, the cathode circuit of the valve 19 which controls valve GFT includes the discharge path between the holding anode and cathode of the ignition.