Chaos via torus breakdown in a forced oscillator including a diode

In this paper, chaos via torus breakdown in a forced oscillator is studied by using a degeneration technique. The authors' model is a negative resistance LC oscillator including a diode driven by a sinusoidal voltage source. The governing equation is represented by a piecewise-linear version of the forced van der Pol equation with asymmetric nonlinearity. In order to clarify the mechanisms of chaos, the idealized case is considered in which the diode in the circuit is assumed to operate as an ideal switch. In this case, the Poincare map is derived strictly as a one-dimensional circle map, which makes it possible to explain the chaos generated in this circuit.<
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