FIELD: electrical engineering; metallurgy. SUBSTANCE: invention, a dual–frequency current inverter, relates to the field of electrical engineering and metallurgy, namely to the power supply systems of induction crucible furnaces. The inverter consists of a single-phase valve bridge, to the AC terminals of which a crucible furnace inductor is connected, shunted by a compensating capacitor, and the DC terminals of the bridge are connected via a filter choke to the output terminals of the rectifier. What is new is that the inverter is equipped with an additional capacitor and two reactors connected in series with the anode or cathode group valves and connected to the output terminals, and the plates of the additional capacitor are connected to the common outlets of the reactors and valves. In addition, a second additional capacitor is introduced into the inverter circuit, connected in series with the first additional capacitor, the common output of which is connected to the midpoint of the inductor of the crucible furnace. The proposed dual-frequency current inverter makes it possible to simultaneously form low and high frequency currents in the inductor. EFFECT: controlling the power supply modes with high and low frequency currents makes it possible to expand the functionality of the induction crucible furnace, increase the efficiency of induction melting and improve the quality of the alloys obtained by controlling the process of mixing the metal with low frequency currents. 2 cl, 2 dwg.