an apparatus includes a circuit , a code modulator , and an actuator . the circuit is operable to detect displacements of a rotating object while in motion . the circuit is operable to detect a position of the displacements and to generate a signal associated therewith . the code modulator is operable to generate a modulated signal based on the position and the displacements . the actuator is operable to apply a force to the rotating object , wherein the force is based on the modulated signal .