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A detection system includes a switch device having a conductor forming part of a capacitor with variable capacitance dependent upon proximity of a person, and a detector for sensing variation in the capacitance and for generating an output signal indicating the proximity of the person relative to th

A detection system includes a switch device having a conductor forming part of a capacitor with variable capacitance dependent upon proximity of a person, and a detector for sensing variation in the capacitance and for generating an output signal indicating the proximity of the person relative to the conductor. The switch device further includes a retaining body adapted to mount the conductor to a door handle, the retaining body also having a mechanical switch arranged for actuation by a person gripping the handle to additionally or alternatively indicate the proximity of the person.

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1. A detection system comprising:a switch device including a conductor forming part of a capacitor having a variable capacitance dependent upon a proximity of a person; and a detector for sensing a variation in the capacitance and for generating an output signal indicating the proximity of the perso

1. A detection system comprising:a switch device including a conductor forming part of a capacitor having a variable capacitance dependent upon a proximity of a person; and a detector for sensing a variation in the capacitance and for generating an output signal indicating the proximity of the person relative to the conductor, wherein the switch device further includes a retaining body adapted to mount the conductor to a door handle, the retaining body having a switch arranged for an actuation by a person gripping the door handle to indicate the proximity of the person, wherein the detector includes an oscillator coupled to the conductor and includes a phase comparator, the variation in the capacitance resulting in an associated change in a frequency of oscillation in the oscillator, to produce a phase modulated signal therein which is input to the phase comparator so as to generate a signal representative of the change in frequency.