GB506521A - Improvements in and relating to electric motors - Google Patents

Abstract

506,521. Induction motors. BRITISH THOMSON-HOUSTON CO., Ltd., MAGGS, A. H., and CHOUDHURY, S. U. A. Nov. 29, 1937, No. 32932. [Class 35] A single - phase induction motor of the capacitor type has on the primary member (1) a main winding 3 having one end connected to a supply terminal 2 ; (2) an auxiliary winding 4 with condensers 5 in series connected to the same supply terminal; and (3) an additional winding 8 co-phasal with the main winding and preferably in the same slots connected at one end to the free end of the main winding ; at starting, Fig. 1, the other supply terminal 1 is connected to the free end of the winding 8 so that the E.M.F.'s of the windings 3, 8 are additive, and during running, Fig. 2, this supply terminal is connected to the junction of the two windings, the auxiliary winding being connected for starting and for running to the supply terminal 1 either directly or through the additional winding whereby the voltage applied to the auxiliary circuit is either stepped up for running or stepped down at starting, and simultaneously with the change in the winding connections from starting to running conditions, the condensers are changed from a parallel to a series connection. The connections shown are applicable to motors operating on supply cir.cuits of 250 volts or less, but for higher voltages, the auxiliary circuit is connected to the junction of the windings 3, 8, the supply terminal 1 being connected to the outer end of the winding 8 at starting and to the junction for normal running. To avoid the establishment of a high potential difference between the outer ends of the windings 3, 8 with this connection, the winding 8 may be entirely disconnected for running. Specification 411,027 is referred to.