| 摘要 |
<p>PURPOSE:To enable to operate an electric railcar without being brought to a standstill by power driving the railcar at an emergency power drive time only while a starting resistor is inserted to an armature circuit. CONSTITUTION:When a defect occurs so that a relay 16 is energized by a chopper open command, an operation coil 10c is deenergized, and an operation coil 11c is energized. Thus, a chopper 12 is disconnected from a shunt field circuit, and a series resistor 13 is connected. Then, operation coils 2c, 5c are energized, current disconnecting switches 2, 5 are closed, and an electric railcar is advanced to a final step of a resistor shortcircuit. Since a cam shaft auxiliary contact 17 is closed when reaching the final step, a slow timer 18 is energized, an open relay 19 is energized after the lapse of the prescribed time, the coils 2c, 5c are deenergized, and a power drive circuit is broken.</p> |
