MAKE YOUR OWN SLOT MACHINE
HOMEMADE COIN MECHANISMS
The simplest is a horizontal slot with a gentle slope behind. The slope has a bit of wire running down each side. A coin simply makes an electrical contact between the two wires as it slides down the slope.
The weight of a coin is enough to trip
the switch as it falls. You can make the coin slot and slide out of metal,
plywood or even cardboard.
if you know a bit about electronics, its even simpler to use a slotted opto switch or inductive sensor, as adjusting the microswitch can be fiddly.
COMMERCIAL COIN MECHANISMS
In the mechanical ones the coins roll down a slope.
Coins of the wrong size and metal fall off and come back out the reject
slot below. Genuine coins travel along the slope and off the end, tripping
a microswitch as they fall. The
Coin Controls S1 (pictured) is available from Eurocoin for
The Coin Controls S1 (pictured) is available from Eurocoin for about £45.
Inside the electronic coin mechanisms, the coin rolls past two coils which sense the eddy currents generated by the moving coin. A microprocessor then compares the eddy currents with those of genuine coins, stored in its memory. An electromagnet then deflects fake coins out the reject slot. Real coins produce an output on a serial or parallel port (the parallel port is simplest to use, one pin usually changes state for each coin denomination).
You can also buy a timer/relay board for it which gives an
adjustable timed output when the
right amount of cash has been inserted. There's even an add on LED display to show
how much has been put in.