How Do Vending Machines Know Which Coins And Notes You Put In?
I heard it was to do with weight and size but they’d have to be very precise and surely coins lose weight over years by being chipped away etc. I’ve tried making fake coins but they never get accepted despite me using the same size and weight as a normal coin.
What about notes, how can a machine read notes? Is it by the serial number?
January 23rd, 2010 at 1:27 pm
Firstly, coin machines detect not only the weight (within a range), but also the type of material. If the material is incorrect, then the coin gets rejected. Also very sophisticated coin detectors have cameras that recognise shapes on the coin and can distinguish between foreign cash.
As for notes (I don’t know much about these but I’ll guess this bit), I assume they have various tests and imagine recognition. Software will detect certain parts of a note to ensure it is genuine. Detectors will also pick up the metal strip and also reflection of UV light. The imagine software allows the machine to recognise what type value of note it is and if it is the right currrency.
January 23rd, 2010 at 1:27 pm
no… they have a trained chimp inside every machine !!!!
January 23rd, 2010 at 1:39 pm
there are little people living inside who check all the notes and coins
January 23rd, 2010 at 3:45 pm
Every coin has “ridges” around it. The machines “read” these ridges. They also “read” bills. For instance some of the newer 5 or 10 dollar bills can not be used in alot of machines. They require the vendor to update the mechanism. Over time these ridges wear and can not be read and that is why machines spit them back out.
January 23rd, 2010 at 4:15 pm
i believe they look for the watermarks and other pertinent info related to each bill plus it reads one , five , ten so can determine bill amount.
What I want to know is how some blind people know the difference…. that just truly amazes me!
January 23rd, 2010 at 7:36 pm
a small goblin with a ruler and scales for coins, and good eye site for notes
January 23rd, 2010 at 10:46 pm
By the weight of the coin, thats why sometimes the vending machine will accept foreign currency aswell.
January 24th, 2010 at 12:21 am
It’s on weight, size and shape.