Method and device for detecting the approach of a foreign body to an object

摘要

The invention relates to a device for detecting the approach of a foreign body to an object, comprising an oscillator 1 and means for applying the output signal of the oscillator to the said object. It comprises a phase comparator 3, means for applying the output of the oscillator to a first input of the said phase comparator, means for linking the said object to a second input of the said phase comparator, and means 15, 32, 33, 35 for generating an approach signal when the output of the phase comparator exceeds a predetermined threshold. IMAGE