Off-gate signals controlled thyristor chopper equipment for battery-operated vehicles using magnetic phase shifter

We have made sustained efforts to develop a method of controlling thyristor chopper equipment by utilizing a magnetic phase shifter. These efforts have crystallized in the production of thyristor choppers used for the Japanese National Railway New Trunk Line cars, battery-operated locomotives used for the construction work of the Seikan Undersea Tunnel, and other projects. We have recently attained further success in developing a new method for controlling thyristor choppers, which is suitable for battery-operated vehicles such as fork lifts and electric cars. In contrast to the conventional method which causes the magnetic phase shifter to control the chopper ON-gate signals, this new method causes the magnetic phase shifter to control its OFF-gate signals. As a result, the chopper's region of a low conduction ratio, often used during brake control of battery-operated vehicles, can be controlled by the magnetic phase shifter region nearby its saturated region, thus quickening chopper response. In addition to this feature, the new method offers many additional merits.