Admotec’s patented position sensor technology (resolver technology) produces a resolver with fewer parts, a solid rotor without slots, windings, or the need for a rotating transformer. And unlike other variable-reluctance resolvers, the Rotasyn utilizes a constant air gap so it is less sensitive to eccentricity and stray magnetic fields. It interfaces directly to standard Resolver-to-Digital (R/D) converters.

Electrical Schematic

Solid Rotor

Unlike a traditional brushless resolver, the Rotasyn position sensor technology has both primary and secondary windings in the stator and thus no transformer is required—the Rotasyn is intrinsically brushless! The transferred energy remains magnetic from the primary coil through the airgap to the sinusoidally shaped poles of the solid rotor. The Rotasyn is similar to a rotary variable differential rotary transformer (RVDT) in which the rotor acts as a magnetic valve completing the flux path.

The total flux through the gap is constant—the rotor determines the angular position within the stator bore where the coupling occurs, and thus the relative amplitudes of the output signals. More detailed information is available in our Understanding_Resolvers_and_Resolver-_to-Digital_Conversion.1.pdf