Switching device actuated by a transponder

摘要

Proposed is a device actuated by a transponder for the generation of a switch signal. The device is based on an oscillating circuit ( 10 ) with a capacitance (C₁), an identification coil (L₁) and an oscillator amplifier ( 12 ). Connected to the oscillating circuit ( 10 ) is a frequency observer ( 20 ) which evaluates the frequency (f₁) tuned in the oscillating circuit ( 10 ) and which when finding a change emits a switch signal (S). A change of the frequency in the oscillating circuit ( 10 ) is effected by the approach of a transponder ( 60 ). The device permits a nearly loadless transponder identification.