APPARATUS FOR MONITORING THE AIR GAP IN ROTARY ELECTRICAL MACHINES USING MAGNETIC FIELD PLATES OR MAGNETO DIODES

摘要

The present apparatus monitors the width of an air gap between the rotor and stator of an electrical machine by bridge circuit means which comprise magnetic field responsive probes located in the stator, preferably adjacent to the air gap. Each probe comprises a magnetic field responsive impedance element, such as a Hall-generator, and a temperature responsive ohmic resistance element. The probes are connected in pairs to form said bridge means, whereby monitoring output signals are produced between diagonally opposite bridge terminals, which are evaluated by, for example, a peak voltage rectifier and an indicating instrument.