Relay circuit for motor control

摘要: In order to precisely position a machine driven by rotating prime mover, the mover (electric motor) is electrically reversed bring it stop. A zero speed switch, mounted on motor shaft, senses when shaft comes stop and at that time deenergizes relay open pair of contacts in series with contactor motor. The switch also opens circuit winding slow-acting which, after delay, closes connected parallel previously-mentioned contacts, prepare for next operation.