| 摘要 |
<p>The coin testing appts. stops an inserted coin in a predetermined position and tests its diameter, composition and thickness. It may also test its weight. To test the dia. the inserted coin serves as one electrode of a capacitor. The coin rests by gravity against an inclined board of dielectric material, on the other side of which arcuate electrodes are arranged such that, for a coin of predetermined dia. one electrode will be opposite a position outside the periphery of the coin and another will be opposite a position inside the periphery. The presence of a coin of predetermined diameter will cause change in the capacity between the coin and the other electrode and is indicated by the capacities between the two electrodes and the coin differing by more than a predetermined value. The composition check involves disposing a coin in an air gap of a single magnetic core having a coil wound thereon.</p> |
