A resolver is a kind of rotary electrical transformer used to measure degrees of rotation. It is considered an analog device, and has a digital counterpart, the rotary (or pulse) encoder. The most common type of resolver is the brushless transmitter resolver. On the outside, this type of resolver appears like an electrical motor comprising a stator and rotor. On the inside, the configuration of the wire windings makes it different. The stator portion of the resolver houses three windings: an exciter winding and two two-phase windings. The exciter winding is located on the top, it is in fact a coil of a turning transformer.