... , sliver, copper, aluminum, material and ect.Melting Electric Furnace, Melting Furnace, Energy-saving Furnance, Efficiency Furnance.main characteristics:Max input ... power factor and power efficiency within the scope of full power.4.With wide frequency range from 1-20KHZ ... Constant output voltage or power control modes are alternative;7.Full display of output power, output frequency, output voltage and ...