A coin detector and counter comprising a coreless oblong transmitter coil and a coreless oblong receiver coil spaced apart on opposite sides of a coin path arranged to cause the entire diameter of each coin to pass between the coils. The maximum peak voltage generated in the receiver coil upon passage...http://www.google.fr/patents/US4998610?utm_source=gb-gplus-shareBrevet US4998610 - Coin detector and counter
