Two-step switching of saturable reactors

The fundamental problem in the analysis and design of magnetic amplifiers is the determination of the unsaturated impedance of the reactor by some test less specialized than insertion in the actual circuit. For tape and ferrite cores driven by very large currents, such as are encountered in computer applications, fairly successful approaches have been developed, although they are still incapable of explaining some observed phenomena.1-3 Unfortunately, cores operating at normal magnetic-amplifier frequencies are not correctly described by these representations, and the designer has been forced to use either extremely idealized models or fairly limited extrapolations from specific measurements.