In the 1970s, new ideas about the transition to turbulence emerged. In particular, it seemed possible to produce chaotic oscillations with three-dimensional dynamical systems. These ideas triggered the search for an electronic circuit producing these chaotic oscillations. Arkady S. Pikovsky and Mikhail Rabinovich designed one which resembles to a van der Pol generator with an additional active element.  It includes a negative conductance -g and a tunnler diode whose characteristic is the cubic function
A sketch of the electronic circuit is shown in Fig. 1.
The governing equations are
With the parameter values 
the autogenerators produces a two-scroll attractor (Fig. 2).
 A. S. Pikovsky & M. I. Rabinovich, A simple autogenerator with stochastic behavior, Dokladi Akademii Nauk SSSR, 239, 301-304, 1978.
 J. Gao J., H. Lü, D. He, L. Stone & Z. Zheng, Unexpected correspondence between noise-induced and master-slave complete synchronizations, Physical Review E, 68, 037202, 2003.