Servo system feedback resolver digital measurement converter - has difference signals for sample and hold converters produced by rectangular resolver excitation waveform developed by zener diode action

摘要

A resolver, used in association with a digital measurement converter for servo system feedback, is excited by a pseudo-rectangular waveform developed by a controlling microprocessor. This produces a voltage rise over an initial period (T0-T1) after which the supply is cut off. In a following period (T1-T3), a Zener diode absorbs the inductive current of the resolver excitation winding and ensures its complete demagnetisation. A corresp. negative peak (T1-T2) results in the latter stage of the cycle. Signal level changes, used in conjunction with following sample : and : hold converters to provide representative feedback, are detected by using a level portion of the initial period (T0-T1) curve (). This provides a stable reference for the circuits which follow. ADVANTAGE - Synthesised rectangular excitation waveform provides stable reference on which difference signals controlling servo feedback can be based.