Graphical Analysis of Nonlinear Circuits Using Impedance Concepts
John S. Thomsen · Journal of Applied Physics · 1953
Equivalent reactances of inductors and capacitors with moderate nonlinearity may be approximated by the usual linear expressions plus terms which depend on the square of the current. With the help of this approximation, the total impedance of an LRC circuit is obtained and plotted in the I-Z plane with frequency as a parameter. The current for any given frequency and voltage may be easily obtained from this plot by graphical means. This method gives an interpretation of the triple-valued frequency response curve in terms of circuit concepts.