Comments on: How Do Vending Machines Know Which Coins And Notes You Put In?

By: Anonymous

Anonymous — Sun, 24 Jan 2010 00:21:41 +0000

It’s on weight, size and shape.

By: Fox

Fox — Sat, 23 Jan 2010 22:46:41 +0000

By the weight of the coin, thats why sometimes the vending machine will accept foreign currency aswell.

By: Anonymous

Anonymous — Sat, 23 Jan 2010 19:36:48 +0000

a small goblin with a ruler and scales for coins, and good eye site for notes

By: lisa n florida

lisa n florida — Sat, 23 Jan 2010 16:15:37 +0000

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!

By: cowgirl

cowgirl — Sat, 23 Jan 2010 15:45:15 +0000

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.

By: charlott

charlott — Sat, 23 Jan 2010 13:39:00 +0000

there are little people living inside who check all the notes and coins

By: jocky674

jocky674 — Sat, 23 Jan 2010 13:27:52 +0000

no… they have a trained chimp inside every machine !!!!

By: Charlie Brigante

Charlie Brigante — Sat, 23 Jan 2010 13:27:05 +0000

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.