Rectifier control equipment 1.Three wires,two-phases and half-wave rectifying mode ... rectification,and direct current will supply to the coil of the electromagent lifter,electromagnet will make out ... switch ,direct current contactor KM1,KM3 release,the coil of the magnet will electro-discharge along with ... up the current dropping of the coil,aslo will speed up the iron billets dropping,about 1~2 second ...