IMPROVEMENTS IN OR RELATING TO DIAGNOSTICS OF A CAPACITIVE SENSOR

摘要

A detector circuit for detecting the presence of a remote capacitive sensor having at least two terminals connected via a protection circuit that includes one or more capacitors, the detector circuit comprising: a current supply for changing the charge on the sensor and the protection circuit, a detector for measuring the voltage on one or more of the terminals; wherein the presence of the sensor is determined by changing the charge on the capacitive sensor and the one or more capacitors of the protection circuit in a predetermined manner such that the voltage measurement on the one or more terminals when the sensor is present is significantly different than when the sensor is absent.