GB198416A - Improvements in or relating to windings for electrical apparatus - Google Patents

Abstract

198,416. Drysdale, C. V. Feb. 28, 1922. Regulating transformers.-A multiple strip winding for the primary and secondary windings of transformers, in which the separate windings may be connected by means of a commutator in series, parallel, or series-parallel, comprises two or more groups of superimposed turns or portions of turns so arranged that the innermost conductor of one group forms part of the same strip as the outermost conductor of the next, thereby securing approximate equality in impedance and magnetic effect in all the windings. A U-shaped strip for forming a coil of two turns is shown in Fig. 1. The portions A, B are coiled in opposite directions from the connecting end C, and each forms one complete turn, the broader extensions D, E forming contact-pieces. To form a multiple winding a number of such strips are superimposed as shown in Fig. 2, so that the connecting portions C are adjacent, insulations being provided between the turns. The broad extensions D<1> - - D<9>, E1 - - E<9> are bent out to form the contactpieces of a series-parallel commutator. The arms A, B of the U-shaped strip may be made long enough to form a number of turns, or a strip may be formed as two or more U-pieces connected in series, as shown in Fig. 4 for a four-turn winding. Fig. 5 shows a coil in which each strip forms a single turn, the connecting points X<2> of one group of strips X<2>, X<3>. X<4> projecting outwardly from the winding, and the connecting points Y<2> of the other group of strips Y<3>, Y<2>, Y' projecting inwardly.