GB760348A - Improvements in or relating to electric circuit arrangements for operating from an alternating current supply (two) or more electric discharge lamps - Google Patents

Abstract

760,348. Supply systems for space discharge lamps. GENERAL ELECTRIC CO., Ltd. Dec. 22, 1954 [Dec. 23, 1953], No. 35791/53. Addition to 730,024. Class 38 (4). The invention comprises improvements in or modifications of the circuit arrangements provided in the parent Specification, by economising in the design of the filament heating transformer 4 in the case of series-connected lamps, and by rearranging the circuit components in the case of parallel connected lamps. In the series circuit, Fig. 1, the transformer 4 has only two secondary windings 5, 6 for each pair of lamps 9, 10, the windings being connected across adjacent electrodes 7, 8 which latter are interconnected by the ballast inductance 15; both end electrodes 16, 17 of the series arrangement of lamps each have one side directly connected to a respective input terminal 1, 2 and the other sides are directly interconnected through a power factor correction capacitor 18, for the supply of heating current direct from the input terminals. In the parallel circuit, Fig. 2, an electrode 7 of one lamp 9 is connected through its ballast inductance 15 to one input terminal 1 and one electrode 8 of the other lamp 10 is connected through its ballast inductance 151 to the other input terminal 2, said electrodes being heated by filament heating transformer secondary windings 5, 6; in each lamp one side of the remaining electrode 16, 17 is connected directly to that input terminal 2, 1 to which the other electrode is not connected, and the other sides of said remaining electrodes are connected directly together through the power factor correction capacitor 18 for the supply of heating current direct from the input terminals. In both arrangements each lamp may be replaced by a plurality of lamps connected in series.