Patent ID: 7816883

Claim:
A return-to-zero control method for a stepper motor coupled to drive a pointer of a gauge assembly including a stop corresponding to a known energization state of the stepper motor, the method comprising the steps of: defining a return-to-zero sequence of energization states for said stepper motor for driving said pointer toward said stop in a series of steps, terminating in said known energization state; identifying a series of steps in said return-to-zero sequence that could potentially drive said pointer away from said stop, and modifying the energization states for the identified series of steps by varying duration of activation and deactivation of said stepper motor during said identified series of steps in a manner to progressively attenuate and then re-apply a return-to-zero torque produced by the stepper motor; and applying the modified return-to-zero sequence of energization states to the stepper motor to drive said pointer toward said stop.