This product series is designed for releasing the holding materials by the energy storage control of the field discharge reversely using three-pin & two-phase half-wave commutation mode.lt features simple wiring,compact and light weight.DKP-A for three-pins & two-phase half-wave controlled commutation controlling equipment.When the power supply network voltage is too high or too low,the potentiometer will be adjusted to make the voltage hold within170-240V and the output voltage appropriately 220V.