GB1515751A - Control circuit arrangements - Google Patents

Abstract

1515751 Control of D.C. motors MARCONI CO Ltd 12 July 1976 [3 Sept 1975] 36193/75 Heading H2J A control arrangement in which a plurality of D.C. energy sources, e.g. batteries are connectable in series or in parallel across a reversible load, e.g. the armature of a motor, or in which a plurality of reversible loads are connectable in series or in parallel across a D.C. energy source, the connection configuration being controlled by means including triggerable unilaterally conductive devices, e.g. thyristors, provided in paths connecting the load(s) and source(s), and energy storage means, e.g. a capacitor, being provided to supply, in operation, energy to the load or loads during periods in which the state of conduction of one or more of the paths is being charged and the triggerable unilaterally conductive device or devices therein are subject to reverse bias as the connection configuration is changed. As shown in Fig. 3, two armatures M1, M2 of a twin-armatured motor are connected across a battery B, thyristors S1-S10, the energy storage capacitor C and inductor L being connected in this circuit. The armatures may be connected for "series forward", "series reverse", "parallel forward" and "parallel reverse" drive by triggering different combinations of the thyristors S1-S8, as discussed with reference to Figs. 4 and 5 (not shown). Additionally, thyristors S9 and S10 may be switched on and off together to control the mean current flowing in the armatures M1, M2. As shown in Fig. 7, two batteries B1, B2 are connected across the armature M of a motor, thyristors S1-S12, the energy storage capacitor C, and an inductor L being connected in this circuit. The batteries may be connected either in series or in parallel and may be connected to drive the motor forward or in reverse by triggering different combinations of thyristors S1-S8, as discussed with reference to Figs. 8 and 9 (not shown). Additionally, thyristors S9-S12 may be triggered on and off to control the mean current flowing in the armature M. Modifications of Fig. 3 are described with reference to Figs. 10, 11 and 12 (not shown). In these modifications diodes are connected in anti-parallel with the thyristors, and an alternative arrangement of the inductor is shown. A modification of Fig. 7 is described with reference to Figs. 13 and 14 (not shown). In this modification, diodes are connected in antiparallel with thyristors S1, S2, S7, S8, S9 and S10.