GB710853A - Transformer for operating hot cathode electric discharge devices - Google Patents

Abstract

710,853. Transformers; supply systems for space discharge apparatus. ADVANCE TRANSFORMER CO. Sept. 12, 1950 [Oct. 17, 1949], No. 22460/50. Classes 38(2) and 38(4) A transformer 1 for supplying n (n being any whole number more than one) series connected hot cathode discharge devices, e.g. two lamps 21, 23, comprises a magnetic core 2, 3, auto-connected primary and secondary windings 12, 16 for supplying discharge current and n+r pairs of series connected auxiliary windings 13, 18; 14, 17 and 15, 19 for supplying heating current to the lamp electrode 20, 22; and 24, 25; the primary 12 and one, 13 ... 15 winding of each auxiliary winding pair being tightly magnetically coupled in a group 10 at one end of the core, and the secondary 16 and other auxiliary windings 17 ... 19 being similarly coupled in a group 11 at the other end of the core and loosely coupled to the primary winding group : the auxiliary windings of each pair are arranged so that their windings are cumulative at no-load whereby when the lamps have struck the substantial reversal of flux in the secondary winding group 11 causes the said voltage to be differentially effective to reduce the electrode heating. As shown, the transformer core is of shelltype having magnetic shunts 6 and air gaps 8, 9 between the two winding groups 10, 11. The connections of the windings 15, 19 are so arranged that the voltage across the terminals 30, 31 due to flow of discharge current opposes the resultant winding voltage. Specification 710,922 which relates to a single lamp arrangement is referred to.