Acceptance checker for Foucault current appts - simulates operation of appts and measures winding currents

摘要

The function of the pick-up of this type of apparatus is simulated and the effective value and frequency of the current passing through the primary coils of the pick-up are measured. An input block provides information proportional to the current flowing in the primary coil and a variable gain amplifier provides a constant amplitude output signal when its input voltage varies in inverse proportion to the frequency of an oscillator. The output of the amplifier is passed via an attenuator to a phase-lag circuit and the output from this circuit is the simulation signal which replaces the output signal of the pick-up and is passed to the visualisation unit, e.g. a CRT.