The simplest electronic circuit that exhibits genuine chaos — a double-scroll strange attractor
Chua's circuit (1983) is the simplest electronic circuit exhibiting chaos. Three nonlinear ODEs govern two capacitors (V1, V2) and an inductor (I). The nonlinear resistor (Chua diode) has a piecewise-linear I-V curve.
The double-scroll attractor is a fractal strange attractor — trajectories never repeat but stay bounded. Sensitive dependence on initial conditions means tiny changes cause exponentially diverging trajectories.