Thyristor control of a multiload system with d.c. supply

A thyristor control system has been developed for several loads energised from a common d.c. supply. All load-controlling thyristors are turned off at regular intervals by an interruptor unit interposed between the supply and the loads. Loads can be controlled, either in an `on-off¿ mode or using mark/space regulating techniques. Several configurations are considered. One is chosen to control 110V auxiliary loads on a diesel-electric locomotive, particularly when the generator field and separately excited traction-motor fields are so energised. Techniques for overcharging the interruptor capacitor to a controlled voltage are presented, including an optimisation of the circuit design. Experimental results on a 1/20 scale model compare favourably with design predictions.