| 摘要 |
PROBLEM TO BE SOLVED: To easily provide a coin identifying sensor in which an error due to a fluctuation in environmental temperature is decreased. SOLUTION: An exciting coil 3 is driven with constant currents supplied from a constant current driving circuit 12, and the temperature fluctuation of a coin material quality identification signal is put in a status where the temperature fluctuation based on the coil resistance value DCR of the exciting coil 3 is removed, and made to correspond to the fluctuation based on the temperature fluctuation of a permeabilityμof a sensor core SC. The temperature characteristics of the permeabilityμof the sensor core SC or the temperature characteristics of an applied voltage from a constant current driving circuit 12d to the exciting coil 3 are previously estimated, and the estimated temperature is easily and highly precisely corrected by a temperature correction means installed in a CPU 14. COPYRIGHT: (C)2004,JPO
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