GB414170A - Improvements in and relating to electric commutator motors - Google Patents

Abstract

414,170. Alternating-current commutator machines. BRITISH THOMSONHOUSTON CO., Ltd., Crown House, Aldwych, London.-(Assignees of Nagashev, B. V. ; 63, Sacremento Street, Cambridge, Massachusetts, U.S.A.) March 23, 1933, No. 8796. Convention date, March 25, 1932. [Class 35.] In a motor having a second field winding connected across an alternating-current supply and in transformer relation with the series winding, means are provided for varying the transformer ratio and /or the phase relationship of the fluxes produced by the two field windings. In the form shown in Fig. 2, the speed of the motor is varied by varying the continuouscurrent input to the winding 21 of a reactor 19, the coils 20 of which are in series with the series winding 13 of the motor. In an alternative form, the armature and series winding are connected in a closed circuit containing the armature of a synchronous motor, the excitation of which is varied to vary the speed and direction of rotation of the main motor. In the form shown in Fig. 3, the motor is used to adjust the electrodes 22, 23 in the circuit Eac which energizes the winding 13 to a higher potential than that induced by winding 14 to cause the motor to bring the electrodes into contact. The motor reverses when the electrodes engage and then separates them by an amount depending on the adjustment of the field windings.