A FAMILY OF WIEN-TYPE OSCILLATORS MODIFIED FOR CHAOS

A family consisting of four Wien-type oscillator circuits are modified for chaos by direct replacement of one of the linear resistors with a n asymmetrical-type non-linearity introduced by a junction field effec t transistor (JFET) operating in its triode region and the addition of a single capacitor. The internal op amp dominant pole is found to pla y a major role in understanding the chaotic behaviour of the proposed circuits. Mathematical models that describe the observed behaviours ar e derived. The well known Wien bridge oscillator design equations are shown to be useful as a starting point for chaos modification. Experim ental laboratory results, PSpice simulations and numerical simulations of the mathematical models are provided for this family of autonomous RC chaos generators. (C) 1997 John Wiley & Sons, Ltd.