Resolvers are devices used to measure the angular position, velocity, and acceleration of a rotating shaft. They are used for a variety of applications, including providing feedback signals for servo motors and controlling automated processes. Resolvers typically consist of two components: a rotor, which is attached to the rotating shaft, and a stator, which is mounted to the stationary part of the system. The rotor contains a winding which is energized with a sinusoidal voltage, while the stator contains a winding which is energized with a reference voltage.