Sorry, this sounds like another semi-private discussion, what board?
edit: guessing it is a carryover from the hotrod resolver discussions? Hi frequency sine wave thingie?
If anyone else is lost, 3 coils and an elliptical rotor, determines shaft electrical angle (don't remove the resolver from the case, it is calibrated at the factory), using techniques akin to sensorless position detection.
edit 2: info about the chip used in the prius
http://www.tamagawa-seiki.com/pdf/do...FT20110708.pdf
http://www.turbo-electric.com/upload...0resolver).pdf
http://web.archive.org/web/200503110...singlsynm.html
$10 chip:
http://www.ebay.com/itm/AU6802N1-Enc...item58a1313133
edit3: I see eclipse identified it 600 posts ago, LOL!