Abstract: An apparatus and method for detecting shaft misalignment wherein a sensor is employed to detect contactings between a non-concentrically rotating component and a surface and to generate an electrical signal corresponding thereto, and wherein a signal processing circuit coupled to the sensor is configured to determine whether the signal received from the sensor is characteristic of a signal that is expected whenever a rotating component contacts the surface, and if so, whether the number of signals received exceeds the minimum number expected within a predetermined time interval on the occasion of contact between a rotating component and the surface.