Abstract: A method of operating an induction furnace so as to receive electric arc furnace (EAF) dust, basic oxygen furnace (BOF) sludge/dust and/or other iron and volatile metals containing materials as a feed stream on a batch, continuous or semi-continuous basis together with a iron-containing material feed, and therefrom produce an iron-containing hot metal or pig iron product while recovering iron value from the feed materials and recovering volatile metal components contained in the feed materials.

Abstract: There is provided a low-noise switching power supply for producing a regulated output voltage from an unregulated supply. The power supply includes a main transformer having first, second and third legs. A primary winding associated with a first leg produces an alternating magnetic flux in the core. A load winding associated with a second leg produces the output voltage from the power supply. A control winding is associated with the third leg. The regulated output voltage is compared to a reference voltage and used to operate a control circuit which alternately short circuits the control winding so as to vary the reluctance pass in the transformer and maintain the output voltage at a substantially constant predetermined value. A feedback circuit including a coupling transformer connects the primary coil to the switching circuit to improve regulation and provide a "soft start" capability.

Abstract: There is provided a low-noise switching power supply for producing a regulated output voltage from an unregulated supply. The power supply includes a main transformer having first, second and third legs. A primary winding associated with a first leg produces an alternating magnetic flux in the core. A load winding associated with a second leg produces the output voltage from the power supply. A control winding is associated with the third leg. The regulated output voltage is compared to a reference voltage and used to operate a control circuit which alternately short circuits the control winding so as to vary the reluctance pass in the transformer and maintain the output voltage at a substantially constant predetermined value. A feedback circuit including a coupling transformer connects the primary coil to the switching circuit to improve regulation and provide a "soft start" capability.