GB190807621A - Improvements in Alternating Current Electric Motors of the Compensated Repulsion Type. - Google Patents

Abstract

7621. Ateliers Thomson - Houston. April 6, 1907, [date applied for under Section 91 of Patents &c. Act, 1907]. Motors, alternating-current; sparking, preventing. -To improve the efficiency and commutation of compensated repulsion motors of the Latour or Eichberg types, having two pairs of brushes a, b normally short-circuited in lines parallel to the axis of the stator winding S<1>, auxiliary electromotive forces derived from a transformer c having two secondary windings d, e, or from two identical transformers each having a single secondary winding, are introduced into the short circuits, the primary windings of the transformers being connected in parallel with the stator winding S<1>, and each secondary winding d, e being short-circuited through a set of brushes. The potentials of stator origin are preferably only impressed upon the rotor at high speeds. In one arrangement, Fig. 1, in which the same brushes are used for the production of the ampere-turns in the two axes of the rotor, the exciting-current is led into the rotor at the midd!e points of the secondaries d, e of the transformer c, but extra brushes f, g, Fig. 2, may be employed for the purpose. According to the Specification in the original form, as open to inspection under Section 91 (3) (a), an auxiliary electromotive force derived from a transformer connected in parallel with the stator winding, or from an additional stator winding having the same axis as the main stator winding, may be impressed upon the " working" brushes of motors of the above types having a single pair of brushes normally shortcircuited, in the axis of the stator winding; this subject-matter does not appear in the Complete Specification as accepted.