Core reset functions in magnetic-amplifier analysis Part II - Determination of amplifier performance

A critical analysis of most practical magnetic amplifiers requires a detailed knowledge of the behavior of the magnetic core. For many amplifiers the analysis may be conveniently separated into two parts: determination of the load voltage or current in terms of the extent of the previous reset of core flux from saturation, and determination of the flux reset in terms of the control or input signal. The output may often be evaluated in terms of the preset flux level with only a meager knowledge of core properties, but to determine the value of the controlling variable needed for a given flux reset or to ascertain the effects and optimum values of circuit parameters requires a more extensive understanding of core behavior. The previously published Part I1 of this paper supplied core-reset functions approximating the relationships between the variables, core flux ϕ, mmf (magnetomotive force) F, and rate of change of flux ϕ', for the process of reset from saturation under certain conditions. In this paper the core-reset functions are contrasted with some other core approximations, several examples of the use of core-reset functions to calculate amplifier performance are shown, and an example of a model theory for the design of analog computers simulating magnetic-amplifier systems is presented.