GB1097303A - Improvements relating to electrical control devices for electrically driven vehicles - Google Patents

Abstract

1,097,303. Variable inductors. WESTING- HOUSE BRAKE & SIGNAL CO. Ltd. June 29, 1964 [July 8, 1963], No. 26903/63. Heading H1T. In an electrically driven vehicle carrying its own power supply source, in which the speed of a D.C. traction motor is controlled by a semiconductor rectifier circuit arrangement, the rectifier circuit arranged is controlled by an output voltage from an induction regulator, the mutual coupling between two coils of which is varied by movement of manually operable means to vary said output voltage and hence the motor speed. The coupling between a pair of coils 1, 3 (Figs. 1 and 2) is varied by moving a magnetic or electrically conductive screen 5 between them. In Fig. 2 the screen may be supplemented or replaced by movable magnetic shunts 7. Alternatively in Fig. 1, the screen 5 may be omitted, and the coupling varied by moving one coil relative to the other or by rotation of core 2 relative to core 4. Also in Fig. 2 the screen 5 may be omitted and the coil 3 moved relative to coil 1. In Fig. 3 arrangement (not shown) the centre limb of an E-shaped core may be moved through the two coils toward or away from an I-shaped core which together with the E-shaped core forms a magnetic circuit. Alternatively in Fig. 3 embodiment one coil may be fixed on the E-shaped core and the other coil and I-shaped core moved relatively thereto. In an embodiment (Fig. 4) the coils 1, 3 are connected in series to an A.C. source E and a voltage output CS is taken from coil 3. The output voltage depends upon the ratio of the impedances of the coils and the impedance of each is varied by moving a short-circuited coil or ring 55 along the core 24 and eddy currents induced in the coil or ring 55 produce a flux barrier. A further coil (not shown) may be connected in series with the coil 3 and arranged as a bucking coil to allow the output voltage CS to be reduced to zero. The bucking coil would be mounted on the core remote from the coil 3. Fig. 5 embodiment (not shown) is similar to that of Fig. 4 but the magnetic circuit is provided with an adjustable core element. In all embodiments the input voltage is applied at E (e.g. at 50 c.p.s.) and the output voltage is available as indicated at CS.