A coin validator is provided with at least two reference positions (U, D) for determining a diameter related characteristic of a coin being validated. In order to reduce the running to the testing station, the timing of a trailing point of the coin passing a first reference position (U) is used to determine...http://www.google.com.au/patents/US6467604?utm_source=gb-gplus-sharePatent US6467604 - Apparatus and method for determining the validity of a coin
