Ferroinductance as a Variable Electric-Circuit Element

This investigation was instituted in an attempt to develop methods which would make ferroinductive circuits as susceptible to analysis as circuits with constant parameters. The work has led to the development of an accurate empirical equation for the magnetization curve of a steel. This equation has been applied in predicting the inductance of a ferroinductor at any value of current, and methods have been developed for measuring this inductance, which check the theory closely. The equation for ferroinductance has been generalized into a relation for effective ferroreactance by an assumption, and experimental evidence has been obtained to support the validity of the assumption. Methods also were developed for calculating the effective resistance of an iron-cored reactor. Application then was made of both of these developments in calculating the impedance of circuits containing ferroreactors, and the results were again well supported by experiment. Another application of the theory was made to the ferroresonant circuit, and simple relations for resonant voltage, capacity required, and the value of the critical resistance secured. All were checked satisfactorily by experiment.