... .b.When we turn on the lifing switch,direct current contactor KM1,KM3 closed,transformer secondary winding and supply alternating voltage ... .c.When we turn on the droping switch ,direct current contactor KM1,KM3 release,the coil of the magnet will electro ... the iron billets dropping,about 1~2 second later,(adjust KT), dropping contactor is power off,then all the iron billets or ...