Simple nonautonomous Wien-bridge oscillator based chaotic circuit

We propose a nonautonomous version of Wien-bridge oscillator with diode nonlinearity. It is a kind of simple circuit which exhibits chaotic behaviour. This oscillator circuit contains an operational amplifier, four resistors, two capacitors, a diode as a nonlinear element and external periodic force. This system exhibits various interesting dynamical phenomena like periodic, quasiperiodic and chaotic oscillations. The detailed analysis is carried out numerically by using two-parameter phase diagram in the forcing amplitude-frequency plane, one-parameter bifurcation diagram, Lyapunov exponents and phase portraits. Most of these numerical studies are in good agreement with observations from experiments.