Oscillating circuit proximity sensor for object detection

摘要

The inductive or capacitive proximity sensor, includes an oscillating LC circuit (10) designed to deliver a signal which varies as a function of the proximity or presence of an object. The sensor has also an oscillator (11) associated with oscillating circuit which generates pulses of a fixed frequency, independent of the presence of the object. A processing circuit (14) connected to the output of the oscillating circuit (10) emits an output signal when the presence of an object is detected. The detector is fitted with a calibrating device which allocates the frequencies for the oscillating circuit and oscillator. The calibrating device includes a regulator (20) for the cyclic pulses from the oscillator (11). The oscillating circuit (10) receives the signal (s3) made up of width modulated pulses from the regulator (20).