GB190510830A - Improvements in Apparatus for Starting and for Regulating the Speed of Compensated Single Phase Electric Motors. - Google Patents

Abstract

10,830. Arnold, E., and La Cour, J. L. May 24, 1904, [date applied for under Patents Act, 1901]. Motors, controlling.-A compensated single-phase series or shunt-wound motor has an auxiliary divided stator winding for purposes of starting and speed regulation, the magnetic axis of the winding being perpendicular to that of the main stator winding and coincident with that of the portions of the armature winding which are not shortcircuited. The main winding of the stator S, Fig. 1, of a series motor provided with four brushes per pair of poles, is connected in series with the auxiliary winding HW and with the rotor winding, the brushes B', B<2> and B<3>, B<4> being short-circuited. The fields due to the non-short-circuited portion of the armature winding and to the auxiliary winding may be co-directional or opposing, so that a very strong or a very weak field may be produced together with a strong cross-field, produced by the main winding S. A point A of the auxiliary winding is connected to one main, and a contact C moves over the winding to vary the number of turns in circuit, the direction of the auxiliary field changing as this contact parses the point A. The auxiliary winding may be divided into a number of coils, which may be connected up in various ways. The motor with the same position of brushes, or with two diametrically-opposite brushes only, may be run with continuous current, in which case the number of auxiliary turns should be the same as the number of non-short-circuited armature turns. As shown in Fig. 2, the current through the auxiliary winding is varied by the variable shunt resistance R<1> or by a shunt reactance. Figs. 3 and 4 show a motor with three brushes, distributed windings being used. Figs. 5 and 6 show the adaptation to a shunt-wound motor, in which the auxiliary winding is placed in series with the main winding as before, but, as the speed increases, the auxiliary winding is gradually cut out. In Fig. 6, the auxiliary winding is connected in series with the armature winding, and the speed is controlled by varying the turns in the auxiliary winding.