GB494507A - Improvements in electric circuit arrangements for operating discharge devices - Google Patents

Abstract

494,507. Supply systems for discharge lamps. GENERAL ELECTRIC CO., Ltd., BOWTELL, J. N., and JENKINS, H. G. Feb. 26, 1937, Nos. 5842, 10026, and 24294. [Class 38 (iv)] Series systems.-In supply systems for discharge lamp assemblies having terminals X, X several feet apart between which a voltage exceeding mains voltage is to be maintained, a pair of step-up transformers is provided, one being arranged adjacent each terminal, the transformers being of the type in which one end of the primary winding is directly connected to one end of the secondary and a free end of each transformer secondary being connected to the adjacent terminal. The primaries are connected in series or in parallel to the mains either directly or through an isolating transformer. In the Figure, a long discharge lamp 1 has its terminals X, X connected to two auto-transformers 3, 4; 3<1>, 4<1>, supplied in parallel from the mains. The transformers may be closely wound or of the high leakage type and may be inside terminal boxes at the ends of the lamp to avoid the use of shielded cable entirely. In the latter case switch contacts may be provided for opening the L.T. supply to the transformer when the lid of the box is opened. The discharge assembly may comprise a number of tubes in series or in parallel with or without separate stabilizing impedances and auxiliary boosting transformers as in the case of a series system described with reference to Fig. 3 (not shown). The electrodes may be heated by the discharge or be directly or indirectly heated by incandescent filaments. In the latter two cases the heating filament may be connected across a tapped part of the secondary of the adjacent supply transformer. British Specifications 23501/99, [Class 38], 389,025, 391,242, and 413,138, [Group XX], and U.S.A. Specification 1,965,249 are referred to.