GB399881A - Improvements in control equipments for electric locomotives - Google Patents

Abstract

399,881. Master control of D.C. motors. HIGGS, G. R., Lintrathen, Kirriemuir, Angus, PRENTICE, T. A., 536, Sandyhills Road, Glasgow, and ASSOCIATED ELECTRICAL INDUSTRIES, Ltd., Crown House, Aldwych, London. April 16, 1932, No. 10952. [Class 38 (iii).] The control circuits of vehicle motors 1, 2, Fig. 1, accelerated by resistances r<1>, r<2> under the control of an accelerating controller A.C., Fig. 2, and changed by closed circuit transition from series to parallel connection by combination switches J, JR, S, P, G, under control of a combination controller CC, are so arranged that by operation of the combination controller from a parallel to a series position, in conjunction with the operation of an auxiliary switch TS, the combination switches for parallel connection are opened, and those for series connection closed, even though the accelerating controller is maintained in the same operative position which it occupied immediately prior to the said operation of the combination controller. As shown in Fig. 2, operation of the switch TS, which is preferably of the pushbutton type, de-energizes the main switch LS1 which by means of its interlock de-energizes the switches P, G, J, and these latter switches in opening complete circuits for the switches S, JR, so that with the combination controller in its series position, and the switch TS released, switch LS1 again closes to connect the motors is series. During this time the accelerating controller A.C. may be left in the same position, so that the amount of resistance in circuit with the motors in series is the same as it was previous to the change. A control system for four motors arranged for series, series-parallel, and parallel control, and including a modification of the invention, is described with reference to Figs. 4 and 5 (not shown). In this system an overload relay is provided to open the resistance contactors, and the line switches on overload, and the contacts of the switch T.S. are included in series with those of the overload relay, so that, when operated, it simulates an overload to open the main switches. In a further modification, Fig. 6 (not shown), no auxiliary switch TS is provided but movement of the combination controller alone is effective to open retaining circuits for the combination switches.