Proximity sensor and its application to remote detection

摘要

This proximity detector comprises a radio frequency oscillator 1 producing a high-frequency signal, a tuned transmission circuit 3 to which the high-frequency signal is applied, and which comprises at least one capacitive antenna 5, whose capacitance is a function of the distance to a foreign body to be detected, reception means 6 forming, with the transmission circuit, a selective coupler 8 for collecting an electric signal at the frequency of the oscillator, and whose amplitude is a function of the tuning of the transmission circuit 3, and a demodulator 9 connected to the reception means 6 in order to produce an output signal which is a function of the said distance. Application to remote detection, in particular in the field of robotics and surveillance of premises. IMAGE