Ergodicity and Entrainment in a System of Electrical Relaxation Oscillators

We consider a system of two coupled relaxation oscillators. This model has been suggested, incorrectly, by other authors as a simple model of chaos. We show that this system is at most ergodic but never mixing. The spectra of both oscillators can be understood in terms of a mutual phase modulation. Finally we include entrainment effects in our description and compare our results with some measurements performed on an electric circuit.