Chaos from two modified oscillator configurations using a current feedback op amp

Two oscillator configurations that employ the current feedback op amp (CFOA) as the active element are modified for chaos using a single discrete nonlinear element, namely a junction field effect transistor (JFET) operating in its triode region. The first oscillator is based on a passive Twin-T structure while the second oscillator is a Wien type oscillator. The generated chaotic signal from both circuits persists for a wide and continuous range of parameter values and in different frequency bands that are easily adjusted by simple parameter scaling. The design equations of both configurations as ordinary sinusoidal oscillators are also shown to be useful when modified for chaos. Experimental laboratory results and PSpice simulations are provided. (C) 1997 Elsevier Science Ltd.