GB213928A - Improvements in or relating to compensated induction motors for single or polyphase alternating current - Google Patents

Abstract

213,928. Deutsche Werke Akt.-Ges. April 6, 1923, [Convention date]. Alternating-current commutator machines. - A compensated single or polyphase induction motor comprises a primary winding a, Fig. 1, and an auxiliary winding c on the stator, a squirrel-cage winding g, a, secondary winding b provided with short-circuiting contacts n, and a commutator winding d on the rotor, the commutator winding being connected through brushes with the auxiliary winding c; the squirrel-cage winding, which is dimensioned for starting purposes only, damps the current in the short-circuited commutator coils at starting and so tends to diminish sparking. The switches f, m, n for the various windings are preferably operated in sequence by a single switch device, and safety fuses may be combined therewith. In a modincation, a switch of the controller type is employed. The Specification as open to inspection under Sect. 91 (3) (a) comprises also the following subject-matter. The secondary winding b, Fig. 2 (Cancelled), may be permanently short-circuited, or closed directly or through slip rings and an external resistance e when the primary a is connected to the line so that at starting the voltage is darnped. As shown in Fig. 7 (Cancelled), the auxiliary winding c and the squirrelcage winding g are placed on the stator and the main winding a on the rotor, the winding b not being employed. By suitable design of the winding g, a special starter may be dispensed with. The switching devices may be mounted together on the motor casing. This subject-matter does. not appear in the Specification as accepted.