DEVICE TO CONTROL SWITCH ELECTRIC DRIVE Russian patent published in 1997 - IPC

FIELD: railway transport; control of switch electric drive using three line wires with DC source used for reversing ac motor. SUBSTANCE: auxiliary relay provides switching of reversing circuit and operating circuit. Interlocking of starting relays precludes false operation when line wires along which switch is changed over and its position is checked are confused. As compared with five-wire system, proposed device provides considerable saving of expensive cable and economy owing to use of small-side reversing relay. EFFECT: cut down mounting cost, prevention of dangerous situations when line wires are confused. 1 dwg