In this work we investigate experimentally the dynamics of a piecewise-linear nonautonomous electronic circuit proposed by Lacy [1996]. In particular, we examine the effect of a dc offset in the input signal. The circuit is first driven by a sine wave with a dc offset. When the amplitude and frequency of the sine wave are suitably chosen and the dc offset is varied, the output of the circuit is found to undergo a rich variety of bifurcations including chaos. A nonzero dc offset can also suppress a chaotic response which persists when the dc offset is zero. Furthermore, for certain amplitude and frequency of the sine wave input with no dc offset, an intermittent response is observed. The intermittent response may be altered by introducing a small amount of dc offset, resulting in a regular periodic motion or fully developed chaos. In addition, by varying the dc offset we have observed mode locking phenomena and a devil's staircase pattern. Finally the response of the circuit to a burst wave input is explored. We find that depending on the parameter values of the burst wave, the circuit may exhibit complex dynamics consisting of intermittency, chaos and mixed-mode oscillations.
A theoretical investigation of mode-locking phenomena in reversed field pinches
