Monday, February 21, 2005
The Coin Mech...
Modern fruit machines take a wide range of coins, 5p 10p 20p 50p £1 and £2 coins
are the norm for a pub machine.
Old machines, in the dim and distant past used to mechanically measure the coinage to make sure it was of the correct size, and they were fairly easy to cheat on, by just making a "fake" coin the exact right size.
New machines are a lot more sophisticated, as they use electronics to determine the coin acceptance. When a coin enters a machine, it usually does not drop straight into the coin mech, as this would make it to easy for people to try to "pull coins" back out of the machine (a process known as strimming).
In order to defeat this (and other types of fraud) the coin first passes through a guide which then drops it down into the coin mech. This guide is designed to make strimming a thing of the past.
A picture of the coin mech is shown below, above the mech is the coin chute guide.
Once in the coin mech, it passes through a channel, where the coin is measured using magnetism from a set or more coils, the coin mech is pre-programmed with the known measurements of several different "good" coins. If a match occurs then the mech outputs a signal to the fruit machines main mother board (mpu) which registers the coin and gives you your play.
As the coin mech relies on detecting the electrical characteristics, a coin does not have to be just "the right size" it has to be made of exactly the same metals, and in the same way as a real coin for it to match.
Coin mechs can be re-programmed to accept virtually any coinage, so owners can update
their machines when new coins are introduced. Fake coins known as "slugs" are in existance, but owners can download updates to make the coin mech aware of these fakes, so they are rejected.
The mechs are not foolproof, but they are do offer a good level of security.
Some coin mechs, particularily in the USA do not hold data for multiple coins, instead they actually compare the coin you put in with readings from a real coin stored in the mech, this means its easy to change the mech to a new coin - but it can only ever handle one type of coin at a time.
Bent coins can cause problems inside the machine, so the coin mech tries to catch those, and jam them so they dont go any further, if this happens the user simply presses a button on the front of the machine, which is physically connected to the mech, this releases the mech door slightly allowing the coin to fall back out into the payout tray.
are the norm for a pub machine.
Old machines, in the dim and distant past used to mechanically measure the coinage to make sure it was of the correct size, and they were fairly easy to cheat on, by just making a "fake" coin the exact right size.
New machines are a lot more sophisticated, as they use electronics to determine the coin acceptance. When a coin enters a machine, it usually does not drop straight into the coin mech, as this would make it to easy for people to try to "pull coins" back out of the machine (a process known as strimming).
In order to defeat this (and other types of fraud) the coin first passes through a guide which then drops it down into the coin mech. This guide is designed to make strimming a thing of the past.
A picture of the coin mech is shown below, above the mech is the coin chute guide.
Once in the coin mech, it passes through a channel, where the coin is measured using magnetism from a set or more coils, the coin mech is pre-programmed with the known measurements of several different "good" coins. If a match occurs then the mech outputs a signal to the fruit machines main mother board (mpu) which registers the coin and gives you your play.
As the coin mech relies on detecting the electrical characteristics, a coin does not have to be just "the right size" it has to be made of exactly the same metals, and in the same way as a real coin for it to match.
Coin mechs can be re-programmed to accept virtually any coinage, so owners can update
their machines when new coins are introduced. Fake coins known as "slugs" are in existance, but owners can download updates to make the coin mech aware of these fakes, so they are rejected.
The mechs are not foolproof, but they are do offer a good level of security.
Some coin mechs, particularily in the USA do not hold data for multiple coins, instead they actually compare the coin you put in with readings from a real coin stored in the mech, this means its easy to change the mech to a new coin - but it can only ever handle one type of coin at a time.
Bent coins can cause problems inside the machine, so the coin mech tries to catch those, and jam them so they dont go any further, if this happens the user simply presses a button on the front of the machine, which is physically connected to the mech, this releases the mech door slightly allowing the coin to fall back out into the payout tray.
# posted by fruityarcade @ 5:20 PM 
