A simple geometrical explanation is given for the 'period-adding' phenomenon observed in the 1927 experiment of van der Pol and van der Mark and refined recently by M.P. Kennedy and L.O. Chua. The problem is reduced to a simple circle map. Some previous results are outlined to show how the same phenomenon arises in a class of van der Pol-type system with periodic forcing, and in conclusion some recent topological results are applied to such systems.
All Science Journal Classification (ASJC) codes
- Applied Mathematics