transmitter resolvers (the type described above). The two diphased windings are energized, the ratio between the sine and the cosine representing the electrical angle. The system turns the rotor to obtain a zero voltage in the rotor winding. At this position, the mechanical angle of the rotor equals the electrical angle applied to the stator. Differential resolvers These types combine two diphased primary windings in one of the stacks of sheets, as with the receiver, and two diphased secondary windings in the other. The relation of the electrical angle delivered by the two secondary windings and the other angles is secondary electrical angle, mechanical angle, and primary electrical angle. These types were used, for instance, as analog trigonometric-function calculators. A related type is also the transolver, combining a two-phase winding like the resolver and a triphased winding like the synchro. See also CORDIC, an algorithm used to calculate hyperbolic and trigonometric functions Incremental encoder LVDT RVDT Synchro External links AMCI Resolver Tutorial Sensors Electric transformers