GB547018A - Improvements in windings for electric transformers - Google Patents

Abstract

547,018. Transformers. BRITISH THOMSONHOUSTON CO., Ltd. April 28, 1941, No. 5448. Convention date, April 26, 1940. [Class 38 (ii)] In order to obtain fractional turn ratios which do not vary with load current, the core of a transformer is subdivided to form parallel magnetic paths and the end turn of one of the windings is correspondingly subdivided into parallel-connected loops each of which embraces one only of the subdivisions of the core. Fig. 1 shows a transformer having a shell-type core in which the required conditions are produced by connecting the secondary winding 21 to a terminal 25 through two parallel conductors 23, 24 which pass respectively through different windows. Fig. 2 shows a core-type transformer in which the magnetic circuit is subdivided by a hole 43, the secondary 42 terminating in two parallel-connected loops 44, 45 embracing sections of the core on opposite sides of the hole. Fig. 4 shows an arrangement in which the effect of of a turn is produced by using three parallel-connected loops 67, 68, 69 embracing three cores 60, 61 62 all of which are embraced by the main part of the secondary 64.