Bipolar motor: rotation, parametric instabilities and chaos

The bipolar motor is a compass in an oscillating magnetic field. It has been intensively studied as a system exhibiting chaos in the years 1980-1990. It was a trendy system, easy to build and to model. However, several regimes reachable by the compass has been left unspoken. The compass can rotate, oscillate or stop depending on internal or exciting parameters. It can also develop parametric instabilities under specific conditions. The goal of this paper is to explain and predict the transition between those regimes and their organization in the parameter space made up of the magnetic field amplitude B and its frequency B. This work is tackling the range of non-chaotic behavior of the compass and it will not overlap the previous studies of the deterministic chaos regimes. It will compare experimental, numerical and theoretical results and demonstrate good agreement between them.