DISPLACEMENT SENSING SYSTEM

摘要

A displacement sensing, system (20) including an oscillator circuit (22) having a characteristic frequency which varies as a function of a magnetic field in the vicinity thereof, an element (24) whose position relative to the oscillator circuit (22) is variedby a displacement, the element (24) being operative to vary the magnetic field in the vicinity of the oscillator circuit (22) as afunction of the displacement and circuitry for sensing a change of frequency of the oscillator circuit (22) over time (delta f/delta t) and for providing an output indication when the change in frequency of the oscillator circuit (22) over time exceeds a threshold.