Testing coins for acceptability involves guiding coins to impact baffle plate, comparing resulting sound with stored sound spectrum, permitting use of coin if coincidence detected

摘要

The method involves acquiring and storing a defined sound spectrum from each permitted coin (1), guiding the coins inserted into the equipment to impact a baffle plate (3), acquiring the resulting sound, comparing it with a stored sound spectrum and permitting use of the coin if a coincidence is detected. An Independent claim is also included for an arrangement for checking coins.