A control device comprising at least one permanent magnet, and a mechanically guided member for enabling a relative movement between a. a first ferromagnetic structure, b. a second ferromagnetic structure comprising at least one electric coil, the electric coil modifying the magnetization state of the second ferromagnetic structure in accordance with the direction and the amplitude of the electric current flowing in the coil, the device furthermore comprising a position detection means for detecting the relative position of the first and second ferromagnetic structures, and a circuit for driving the supply current of the coil, which varies as a function of the signal delivered by the position detection means.