| 摘要 |
<p>A discriminator for coins and tokens monitors the extent to which an alternating electromagnetic field is coupled through a deposited coin and a reference coin, as the deposited coin passes along a feed path. A first electromagnetic field is incident on a reference coin along an axis normal to the reference coin and displaced from a midpoint of the reference coin. As the deposited coin moves through a second electromagnetic field traversing the feed path, the deposited coin passes two positions at which the second electromagnetic field is aligned to the deposited coin to a same degree as the first electromagnetic field is aligned to the reference coin. The electromagnetic fields preferably are provided by two series connected coils in a stack, and the fields passing through the coins are added at opposite polarity by a receiver coil placed between the series connected coils (and also between the sample coin and the deposited coin). The received signal is rectified, filtered and digitized, whereupon at least one of the following may be ascertained: the received waveform shape, the maximum and minimum peak levels, and the timing characteristics. This ascertained information, and detected data of an optical code on the deposited coin, can be compared to stored criteria, for passing or sorting coins.</p> |
