Abstract: The present invention relates to an apparatus for accepting or rejecting a single type of coin, which is designed and constructed only to accept genuine coins of a particular value or denomination, and to reject spurious coins or slugs which may have the same dimensions. The present invention also provides an auxiliary coin acceptor-rejector component or device which may readily be fitted into already existing coin operated devices so as to discriminate more accurately between genuine coins and spurious coins or slugs. In such apparatus a sensing coil is provided for discriminating between genuine and non-genuine coins by suitable circuitry to actuate an accept solenoid to receive a genuine coin in an accept slot and to direct all other non-genuine coins to a reject slot. To discriminate between genuine and non-genuine coins two parameters are utilized.

Abstract: The present invention provides a single coin acceptor or rejector for use with coin-operated machines, which has an oscillator circuit and a sensing coil, wherein the oscillator oscillates at a constant amplitude, and has sufficient gain that it will continue to oscillate at such constant amplitude when a coin is placed within the sensing coil. A field effect transistor (F.E.T.) which is utilized in the circuit becomes in effect a variable resistor, the value of which is controllable by materials passing through the sensing coil. Such effective resistance changes are detected by a resistor connected in series with the F.E.T. and which functions as a current to voltage converter.