I am working on a microcontroller based project, which is to be coin operated, but do not yet have a working coin collection system.
I have a quantity of devices described as "coin sensors" which came as freebies along with some other wanted components which I bought some time ago. They consist of three flat coils mounted side by side, with two slots in between, where coins could be passed through. The two outside coils are wired in series, but the centre coil is a separate circuit. I tried connecting one coil circuit to a signal generator and the other to a CRO to see what response they gave when a coin was passed through them. There was a response, but it was not consistent, and did not adequately distinguish between coins of different values, or steel washers, whereas the commercially available coin receivers costing several hundred dollars, and which appear to operate on a similar principle,are able to distinguish between coins of different values
Could someone please give me information on how they achieve this, or alternatively, how the coin sensors which I have, are intended to be connected.
Harry