Motion detector according to the Ferraris principle

摘要

In a motion detector according to the Ferraris principle, an excitation element applies an inhomogeneous time-dependent alternating magnetic field to an induction element. A motion of the induction element induces in the induction element an eddy current with a temporal characteristic that depends both on the velocity and the acceleration. A sensor element measures the temporal characteristic of the eddy current and supplies the temporal characteristic to a signal processing circuit which determines at least one useful signal that is proportional to the velocity and acceleration, respectively.