A non-contact multi-turn angular position sensor

In a variety of applications the absolute angular position of a shaft needs to be determined for more than one revolution. Frequently this absolute position must be available immediately after power up without returning to a reference position. This is usually achieved by using a gear reduction together with an absolute measuring angular position sensor. Due to durability concerns of the gear, this approach maybe undesired. We present a novel concept for a fully non-contact absolute multi-turn sensor and experimental results for a prototype with a measurement range of 5760/spl deg/ and an accuracy 0.2/spl deg/.