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How do these machines work (parking meter, etc )

  1. Apr 25, 2009 #1
    Hi guys ,, how are you all ??

    my teacher had us to make a report about parking meter and the coins we are using for it ,,

    the new issued ones doesn't work with the parking meters ,, so i have a question ...

    how does parking meters , Pepsi machines and other machines that you have to insert a coin work ?? by mass ? density ? or diameter or thickness ? of the coin
    and how do they work for the paper coins ?

    if anyone got an article about how do they work it would be really helpful :)
    Last edited: Apr 25, 2009
  2. jcsd
  3. Apr 25, 2009 #2


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    Staff: Mentor

    The old style that used coins went by mass and size. The ones that read paper money actually have a scanner and software that identifies the bill by sight.
  4. Apr 25, 2009 #3


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    Gold Member

    Some more security conscious machines also check the magnetic properties of a coin to make sure that it contains the right metals.
  5. Apr 25, 2009 #4
    about the old styles ,, you mean it measure both the mass and size together or one of them ,, and about size you mean the dimensions or volume or density or thickness ?? ,,could be more specific..

    another thing ,, in some machines if you insert a quarter or a half it can distinguish between them even though they are different in mass and size ..
  6. Apr 25, 2009 #5
    do you mean like in arcade games in centers ?
  7. Apr 25, 2009 #6


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    I'm not sure about arcade games, but things like movie ticket dispensers, VLT's, etc. incorporate that technology.
  8. Apr 25, 2009 #7


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    Coin accepting machines are actually quite complicated htese days (thank you Modern marvels!). Bills are, as already said, scanned optically. Coins are verified optically and i believe with sound pulses to verify what they're made of. Kinda cool from what i remember...
  9. Apr 26, 2009 #8
    so you mean bye bye old coin machines ... thanks everyone :)
  10. Apr 26, 2009 #9
    I only recall this from a TV show I saw once, so I'm not sure it's that accurate. In the early days of pay phones, an operator on the far end was trained to recognize the sound of the coin falling. I'm not sure if it was the coins falling on the same disc, or different sized coins going to different sounding bells. Think it may have been the history channel.
  11. Apr 26, 2009 #10


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    I remember that from when I was a kid.
  12. May 3, 2009 #11
    It's a cost-benefit ratio.

    Traditional "gumball" machines have the lowest monetary authentication technologies.
    Food/personal accessory product vending machines are the next highest.
    "Coin-changing" machines use even higher technology.
    Casino gambling machines use the very best monetary authentication technologies within that scope of cost.

    Of course, this is not all inclusive. Likely there are are still some coin-changing machines out-there that can be fooled, for example, but most business people are fully aware of this and thus upgraded.
  13. May 17, 2009 #12
    Its my first post, so i will make it count. Arcade machines make use of two methords, the first being the stock size/weight check. The second is the measurement of electrical resistance of the mass it self. If all is good the machine will pass it, if not it will be rejected... (you could glue two 1c pies together to make the rough shape of a Australian 2doller coin, SteertFighter1,2,3 by Capcom) until the machine was updated or you ran out of 1c coins.)
    Melbourne parking meters used to use two types two types of authintecation the first being a visual cue, you could actually see the coins in the "weigh bridge" the second was a simple size auth. so you could use a straw to push the size pin a couple of times then insert two coins for the visual auth. All parking meters in Melbourne are now digital and are now fraud proof...
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