Coin discrimination apparatus

摘要

In a metal body discriminating apparatus eg for a coin 21 the coin passes through a coil 24 forming part of an oscillator circuit. Changes in the frequency and amplitude of an oscillation signal in response to changes in impedance and inductance of the coil by the operation of the eddy current which is generated in the metal body by the magnetic lines of force by relatively moving the metal body through the coil are detected as feature parameters of the metal body. In a second embodiment two or more coils forming a similar oscillator are arranged at regular intervals and the size of metal body is discriminated from each of the oscillation signals having a phase difference which are obtained when the metal body passes through the coils.