A Feedback Method for Obtaining a Synchro Output Signal Proportional to Input Angle Θ for Large Θ

If the ac signal at the "cosine" terminal of a sine-cosine resolver (or synchro transmitter connected to a transformer so as to perform the function of a sine-cosine resolver) is fed back to the rotor through an amplifier of suitable gain, the signal at the ``sine'' terminal can be made proportional to rotor rotation for angles up to 90/spl degrees/ or greater. A theoretical analysis of the relationship θ ÷ sin θ/a + b cos θ is given, along with a method for deriving its analog. The theoretical development is supported by experiment.