Abstract: A stabilized saturated reactor comprising a solid toroidal core of magnetic material. The core has at least one end face provided with plural circumferentially spaced slots. Each slot extends in a substantially radial plane with respect to the central axis of the core. Each slot has a width substantially less than the cross-sectional dimensions of the core. The core may have a second end face which is provided with plural slots staggered circumferentially in relation to the slots in the other end face to simulate a linear reactor. The core, with both end faces slotted, may be combined under a common winding with an unslotted saturated toroidal core spaced therefrom to simulate the stabilized saturated reactor core having only one slotted end face.

Abstract: A direct current modulator provides double frequency variable A-C power to a load (such as an induction furnace or induction heater) specifically adapted to operate at the double frequency. The direct current modulator includes a saturable reactor bridge circuit having impedance balanced windings which function as magnetic valves. The windings are connected to provide first and second zero A-C potential terminals to which D-C magnetization current is connected. A source of D-C magnetization current is provided by a direct current circuit in which the modulated direct current flows. The direct current circuit includes the load, a rectifier and transformer connected to a source of A-C power. Capacitance and reactance may be provided in circuit with the load for bypassing the D-C component of the modulated D-C current which flows through the load.