The invention concerns a magnetic device for regulating the relative angular velocity of a wheel and of at least one magnetic dipole integral with an oscillating device. The wheel or the dipole is driven by a driving torque. The wheel includes a periodic, ferromagnetic pole path which alternates according to a center angle and the at least one dipole is arranged to permit magnetic coupling with the ferromagnetic path and oscillation of the dipole at the natural frequency of the oscillating element during the relative motion of the wheel and of the magnetic dipole to regulate the relative angular velocity. The wheel further includes an assembly to dissipate the kinetic energy of the at least one dipole when it moves away from the ferromagnetic path.