Resonant sensor

摘要

A resonant sensor of a simple structure for use in an electronic security system, which can increase the reliability of electronic deactivation therefor, is disclosed. The resonant sensor comprises a resonant circuit having an induction coil (30), wherein a conductive piece (50A) is provided on the induction coil through an insulating layer, over a plurality of turns of the induction coil (30). <MATH>