ELECTRIC TRAIN SPEED CONTROL DEVICE Russian patent published in 1998 - IPC

FIELD: transport engineering; electric systems of vehicles with DC motors; speed control devices for underground cars. SUBSTANCE: device has two groups of series-connected traction electric motors with corresponding controlled starting resistors. Four switching members are also provided three of which are made in form of thyristors and one, in form of diode. In process of starting, groups of electric motors together with starting resistors are placed first in series circuit and then in parallel circuits. Switching member connected between terminals of starting resistors at side of motors provides automatic monitoring of value of equalizing current between parallel connected motors and disconnection of equalizing circuit under no current. EFFECT: improved operation reliability of device. 1 dwg