GB935265A - A rotary alternating-current motor - Google Patents

Abstract

935,265. A.C. motors. REGULATOR A.G. Nov. 13, 1961 [Nov. 15, 1960], No. 40454/61. Class 35. In a rotary A.C. motor the rotor carries at least one winding connected in a closed circuit which includes a unidirectionally conductive element 29, and the stator 15 for co-operating with the winding comprises two separate magnetic systems which respectively create alternating and unidirectional magnetic fields. As shown, the winding comprises ribs 17, 25 printed by etching copper layers on the opposite sides of an insulating disc 11, interconnected by rivets 27, and so arranged that their radial portions 19 on the two sides are circumferentially spaced. The alternating field, created by a source 31 supplying one or more electromagnets 33, 35, induces in the rotor winding 17, 25 an alternating tension which results in a pulsating unidirectional current in the closed circuit, and the application of the unidirectional field, created by a source 41 supplying electromagnets 37, 39, to adjacent ribs 17 or 25, sets up a driving torque, the direction and magnitude of which depends upon those of the D.C. voltage selected by a voltage divider 43. Speed control may also be effected by varying the current strength in coil 35 or displacing one or more of the electromagnet cores. The unidirectional field alternatively may be created by one or more permanent magnets, and the invention is also applicable to motors having cylindrical or drumshaped rotors with wire coils. The element 29 may be a germanium diode.