GB130642A - Improvements in and relating to Dynamo Electric Machines. - Google Patents

Abstract

130,642. Plaisant, G. June 22, 1917. Homopolar machines ; armatures and field magnets; windings. -To generate asymmetric electromotive forces of the general character shown in Fig. 10 for engine ignition, wireless telegraphy, &c., a ring or hollow drum armature c<1>, Figs. 1 and 2, is situated in a radial magnetic field produced between a small inner pole a and a large outer pole b of the field magnet, one or both of the poles being discontinuous in the circumferential direction. The armature c' is stationary, while the pole a is connected to the rotating shaft e' by means of an arm e. The large pole may be arranged inside and the small pole outside the armature. The excitation may be effected by a winding d either mounted on the arm e, Fig. 1, or placed at the base of the large pole, Fig. 2; in the latter case, the arm c is of non-magnetic material. The larger pole b may be the movable element, or both poles may rotate in the same or in opposite directions. The large pole may be of circular form or of crescent outline, as indicated by dotted lines b<2>. The armature c<1> may be wound in accordance with the simple diagrams of Figs. 3, 4, and 5, a complete winding consisting of a number of such elements connected, for example, as shown in Fig. 9. The ends of the windings are joined to slip-rings. The curves A, B, C of Fig. 10 illustrate wave-forms obtained with an ordinary gramme, ordinary drum, and the 8-winding shown in Fig. 3, respectively. Specification 26177/12 is referred to.