Abstract: A coin sorting apparatus in which the oscillation constants of oscillators change with the passage of a coin, and the amount of change in each of the oscillation constants or a value converted therefrom is compared with a reference value of a coin to be identified which is stored in a memory to identify whether the coin is genuine and the class thereof. Whether the reference values for each coin are corrected is determined by a plurality of counters which correct the reference values of corresponding classes of coins when their counts exceed a predetermined set value. At the same time, when the inserted coin is identified as genuine, a corresponding counter is activated, thus improving the performance of eliminating spurious coins without reducing the acceptability of genuine coins even under ambient temperature changes or secular variations of component elements with time.

Abstract: A coin selection apparatus comprises a plurality of detection coils and an oscillation circuit which detects changes of impedances of the detection coils caused when a coin pass through the detection coils, as a change of a voltage output. The plurality of detection coils include at least two sets of detection coils each including two detection coils opposingly arranged to the coin path. One set of detection coils has its two coils connected in series and in phase and the other set of detection coil has its two coils connected in series and in phase opposition. The two sets of coils are arranged at a spacing along the coin path smaller than a minimum diameter of a coin to be selected and all of the coils are connected in series and connected as a resonance element of the oscillation circuit. Thus, material, thickness and diameter and other appearance characteristic of the coin are detected based on the voltage output of the oscillation circuit.