Patent ID: 6145646
Filing Date: 2000-11-14
Classification: G07D,H04N

Abstract:
Apparatus for testing the authenticity of coins (M), tokens or other flat metal articles, which has an inductive measuring element with a coil for characterizing the coin, wherein the coil can be fed with a first current from a first current or voltage source and wherein a phase shift which serves as a criterion for acceptance or rejection of the coin is measured, characterized in that the coil can be fed with a second current from a second current or voltage source, that a capacitive element C.sub.1 is connected between the coil and the first current or voltage source, the coil and the capacitive element C.sub.1 forming an impedance Z.sub.1, and that the phase shift .phi..sub.1 between the first current I.sub.1 and the voltage across the impedance Z.sub.1 serves as the phase shift.