Payout
You may notice a great variety of payout systems when playing slot machines. Let’s look at one of the simple designes. A jackpot is detected by measuring the depth of notches in the discs that drive the reels. To make it simple, we’ll look at this sort of payout system in bare-bones slot machine. Only one kind of coin is accepted here, and there is only one winning combination of images.
An inserted coin falls into a TRANSPARENT CASE, which bottom is a movable SHUTTER that is connected to a metal linkage. You can see it in the diagram. Generally, the shutter is held closed by the linkage. Yet, when the jackpot is being hit, the linkage is shifted up by the third stopper. At this moment, the shutter is being opened and the coins fall out of the machine.
Each of the three discs has notches for each stop position of the reel. The notch for the JACKPOT STOP is deeper than the other stops. Accordingly, when the first reel stops on the jackpot, the first stopper moves further to the left than it would for any other stopper. The same happens, if the second reel lands on the jackpot- the second stepper also moves further left. And consequently, the same goes for the thirs reel and stopper.
However, if the second reel stops on the jackpot, the second stopper will not move all the way onto the notch. It is due to the first stopper catch which prevents the second stopper from moving past it. Seemingly, the third stopper is held back by the second stopper catch. Now we are getting close to jackpot. All we need is the first and the second reels land on the jackpot image. Then, the shutter would open and dump all of the coins that have been played since the last jackpot.
Some electrical machines use another system. A series of METAL CONTACTS is attached to the discs. At the moment of the reels stop, a stationary contact wired to a circuit board is possible due to one of the contacts. This enables every stop of each reel to close a different switch in the electrical system. And finally, some combinations of closed switches ( jackpot winners ) will arrange the machine’s electrical circuit to operate the payout mechanism.
There is even more sophisticated system. It uses PHOTOELECTRIC CELLS (called photo diodes), which generate a current when exposed to light, to detect the position.
The system provides a series of holes which are drilled through the rotating discs, all around their outer edges. The photo diode is situated on one side of the disc, and the light source comes from the other side. At the moment the disc is turning, the light shines through the holes onto the photo diode. The pattern of holes in the disc makes the photo diode generate a similar pattern of pulses of electricity. On the basis of the pattern, the reel position can be established by an electronic circuit.
In the next article, we’ll focus on the latest slot machines, which use computers instead of GEARS.
