Abstract: The differences between two pairs of the three windings of a synchro stator are individually scaled so as to provide a function of the rotor angle plus a 45.degree. phase lead. The scaled values are applied to a CR/RC bridge, the output of which bears a phase relationship relating directly to the synchro rotor angle, but is identical for shaft angles from 0.degree. to 180.degree. and from 180.degree. to 360.degree.. These signals are shaped and applied to a pulsewidth modulator; the pulsewidth modulation ambiguity is resolved by generation of a sign bit indicative of angles between 180.degree. and 360.degree.. The pulsewidth modulated output is converted to an analog level, as is the reference supply voltage, and an analog to digital converter provides a digital output as a function of the ratio of the angle voltage level to the reference voltage level. The sign bit is provided as an additional digital bit thereby providing a digital output indication of shaft angle.