| 摘要 |
<p>A coin validator (10) comprises a slot (14) which accepts coins (20, 20A) of a predetermined diameter and thickness with a small clearance, a guide (12) which receives coins from the slot and a sensor (9) which senses coins moving along the guide. The guide has divergent sidewalls (18) so that a coin of predetermined denomination to be validated will pass close to the sensor whereas smaller coins will pass at a greater distance from the sensor. Validation is achieved by the sensor being arranged to sense the distance (X) at which the coin passes. Preferably, the sensor comprises capacitive plates (13, 15) which form a capacitor with the passing coin, the capacitance accordingly varying dependent upon the distance at which the coin passes.</p> |
