CATEGORY : POSITION SENSING AND FEEDBACK

Resolvers A robust, absolute position sensor

The resolver is a highly accurate and highly dependable device for absolute position shaft encoding. Resolvers have a reliable track record of applications in aerospace, military, and industry, where they have been used for decades for position sensing. Some of the common applications are radar antenna position sensing, missile guidance systems, NC machine position feedback, automotive stamping presses 2-piece can manufacturing presses, and packaging machines. The resolver is designed to operate reliably under extremely hostile environments, such as continuous mechanical shock, vibration, extreme temperature and humidity changes, oil mist, coolants, and solvents.

The resolver is a passive transducer. It is a brushless rotary transformer with one rotor and two stator windings. The stator windings are electrically 90 out-of-phase with each other. As the shaft rotates, the relative position of the rotor and the stator windings change. Either the rotor or the two stator windings together can be used as the primary of the rotary transformer and the secondary will then produce an analog voltage corresponding to the shaft position.