It sounds like you're thinking of separating coins using eddy current braking [1]. This works even for non-magnetic coins because the effect is a function of the metal's electrical conductivity.
If you have a silver coin or a small piece of copper pipe and a large, strong neodymium magnet, then you can easily observe this effect at home by putting the metal sample on a table and quickly waving the magnet past it as close as you can without touching it. The metal will slide across the table following the magnet, despite the metal itself not being magnetic, because the moving magnet induces eddy currents which temporarily create a magnetic field like an electromagnet. Other metals besides silver and copper exhibit weaker responses due to higher electrical resistivity.
Thanks for explaining. Wondered how non-ferro coins were handled.
TD Bank in Canada had coin counting machines for customers for a while. I dumped a few hundred $ in and was very happy when it kicked back some silver coins to me.
A coin drops at a known speed and the right coin will get pulled by the right amount by a magnet or get rejected.