Flux compensated rotational position detector and operating methods therefor

A flux compensated rotational position detector, comprising:

• a rotating element having a plurality of magnetic poles extending over its entire periphery;
• and
• a fixed element having protruding fixed-element N magnetic poles with respective fixed-element magnetic pole teeth opposing the rotating element;
• and
• first and second flux compensating means for generating compensating magnetic flux,
• wherein:
• the fixed element does not form a closed magnetic path around the entire periphery of said rotating element;
• magnetizing windings, sine output windings, and cosine output windings are provided on each of the N magnetic poles;
• the compensating magnetic flux tailors flux profiles adjacent to the 1st and Nth ones of the N magnetic poles;
• and
• N is a positive, even integer.

A method of operating a rotational position detector including a rotating element having multiple magnetic poles, and a fixed element having N protruding fixed-element magnetic poles with fixed-element magnetic pole teeth opposing the rotating element, wherein the fixed element does not form a closed magnetic path around the entire periphery of the rotating element, the magnetic poles supporting magnetizing windings, sine output windings, and cosine output windings, N being a positive integer greater than 2, comprising:

• generating compensating magnetic flux proximate to opposing sides of 1st and Nth of the N magnetic poles;
• energizing the magnetizing windings;
• and
• determining the position of the rotating element based on output voltages generated by the sine and cosine output windings.