GB614509A - Improvements in and relating to starting arrangements for electric discharge devices - Google Patents

Abstract

614,509. Supply systems for space discharge apparatus. BRITISH THOMSON-HOUSTON CO., Ltd. July 17, 1946, No. 21432. Convention date, July 19, 1945. [Class 38 (iv)] [Also in Group XL (a)] Quick starting from A.C. or D.C. of electric discharge devices, e.g. a discharge lamp 1 without the necessity of preheating the electrodes 2 is effected by an oscillatory current generated in a starting circuit 11 connected between the electrodes and comprising an impedance 14 in series with a parallel combination or loop circuit of condenser 12 and auxiliary discharge device 13. The loop circuit is inductively coupled, as by a high-frequency transformer 16, 17, with the series portion of the starting circuit instead of with the operating circuit, as in Specification 601,360. The device 13 (see Group XL (a)) is arranged to break down at a voltage lower than the lamp opencircuit voltage and the resulting oscillatory current in the loop circuit induces in the secondary 17 of the transformer a voltage which is added to the open-circuit voltage on the lamp to initiate the main discharge. The starting circuit may include the filamentary electrode(s) of a lamp. Specifications 545,935, 556,428, 559,898 and 569,685, [Group XL], also are referred to.