Improvements in and relating to methods of grid control of gridcontrolled vapour or gas discharge devices operating as inverters

摘要

412,528. Converting. BRITISH THOMSON - HOUSTON CO., Ltd., Crown House, Aldwych, London. March 15, 1934, No. 8198. Convention date, March 15, 1933. [Class 38 (ii).] In a parallel-type inverter comprising gridcontrolled gaseous discharge devices 2, 3 associated with an output transformer 4 and commutating condenser 6, the grid potentials are derived from the D.C. side 1 of the inverter through an oscillation generator comprising a glow discharge tube 13, a condenser 11, and a grid-controlled auxiliary discharge device 15. The condenser 11 is charged through a resistance 12 to the breakdown voltage of the tube 13, whereupon flow of current through a resistance 14 causes the grid of the device 15 to assume such a potential that the latter becomes conductive, whereupon the condenser 11 discharges, and the sequence is repeated. The periodic variations in potential across the device 15 are applied through a condenser 17 to the grid transformer 8 whereby steep fronted potential waves are applied to the grid of the valve 3. In order that waves of similar characteristic may be applied to the grid of the valve 2, a voltage derived from the choking coil 7 on the input side of the inverter is superimposed on the voltage of the grid transformer.