A transducer using a short-circuit rotor

AS CONTROL EQUIPMENT becomes more automatic and accuracy requirements increase, more highly specialized position-sensing equipment becomes necessary. In the signal-generator type of position-sensing equipment, angular rotation of the input shaft causes a proportionate voltage to appear as the output of the device. It is usually desirable that the output be of line frequency and phase sensitive, that is, that the voltage increases on either side of a minimum or null voltage position and the phase of the output shift 180° as the rotor passes through the null position. This article describes a signal generator which has two unique characteristics: (1) the output is practically unaffected by linear motions of the rotor, and (2) magnetic side pull on the rotor is negligible even when the rotor is not centered.