摘要 |
An electronic circuit designed to control entirely by electronic means the change from traction mode to braking mode and vice-versa of a separately excited DC machine and the forward and reverse operation of the motor as well as rheostatic braking. The chopper includes two main thyristors (T1) and (T2) and a single switch-off thyristor (T3) for the two main thyristors. The direction of current flow through the separate excitation winding (J) is determined by four thyristors (T5) to (T8). Application to railway traction. |