Digital position sensor including L/C sensing oscillator

摘要

A position sensing element forms a reactance (inductive or capacitive) in the L/C tuning circuit of an oscillator. The reactance varies as a function of the position of the sensing element relative to a predetermined object. This causes the resonant frequency of the oscillator to vary as a function of the position of the sensing element. The output of the oscillator is squared to provide a square wave signal, the frequency of which is a direct function of the position of the sensing element relative to the predetermined object.