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Coin sensor

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

Reply to
Harry Pfeifer
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Can you take a photo of it and post it to a website somewhere? Typically there are 2 main types of coin validators. One is an electronic unit that measures metallic content and then either sets an output high or sends a serial message. These can be single denomination or multi denomination. The latter being far larger in size.

The other type is a single denom coin comparator. These measure the metallic content of a reference coin then compare it to the coin traveling through the slot. They are typically analogue devices that from memory run from 24VAC. Most will divert the coin to another chute if it does not match, with the actual coin count being handled by a photointeruptor. In fact, there is usually 2 sets of optics that can also detect coins going in the wrong direction in case some is trying the ol coin 'YO-YO'!

Reply to
The Real Andy

Old Telstra yellow payphones used weight to accurately detect coins, this was good enough to determine if a coin was Australian or Kiwi as the identical sized Kiwi coins were of a different weight but identical size and most likely to end up in a coin slot. I forget if they had different diameter chutes for the coins to be sized in before weighing but they passed extensive testing using slugs, washers etc.

Reply to
Mark Harriss

easiest way is to buy one, Microsystems Corp. makes a good product.

it sounds like he could place a good coin in one of the slots and then feed one of the coils with a reference signal [maybe a 1Khz square wave?] and look for a null on the other coil when another coin of the same type passes through the other gate,

Bye. Jasen

Reply to
jasen

True this is, but did the OP not ask about an existing unit?

You have no idea, perhaps its time you stopped pretending to be a genius by reading the internet and focused on shit you actually know something about.

Reply to
The Real Andy

Ebay. Pinball machine section. Can usually be had cheap.

Rob

Reply to
R1rob

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