A position determining system for determining a position of a rotor of a rotating motor has sensors that are coupled to the rotor. The sensors generate, in response to a rotation of the rotor, a quadrature signal that has sine and cosine components. The position determining system calculates a sum (A.sup.2) of a squared value of the sine component (A.sup.2sin.sup.2x) and a squared value of the cosine component (A.sup.2cos.sup.2x). An amplitude correction factor (A) is calculated as the squared root of the sum (A.sup.2). An amplitude corrected sine component (sin(x)) is obtained by dividing the sine component (Asin(x)) by the amplitude correction factor (A). An amplitude corrected cosine component (cos(x)) is obtained by dividing the cosine component (Acos(x)) by the amplitude correction factor (A).
In one embodiment, a sensor assembly for measuring an angular position of a rotatable structure includes an annular ring that is eccentrically rotatable about an axis, a first and second sensors, and an sensor transducing circuit for combining the respective output levels from the two sensors. The first and second sensors are rotatable relative to the annular ring and disposed a predetermined distance from the axis such that the first and second sensors have a first and second output level respectively that is proportional to the angular position of the annular ring. The sensor transducing circuit is operable to proportionally combine the first and second output levels into an output signal based upon a weighting factor, the weighting factor being proportional to angular position of at least one of the first and second sensors.
