Michael S. writes: My friend and I were talking about vending machines today, and we both wondered what technology the machines use to quickly determine the monetary value of either a coin or a bill. It amazes us that they can reliably accept the variety of money that they do. Is there an article somewhere that explains the fun geek stuff that goes on in these detectors?
No doubt there’s some serious science to the whole process. Try Money Controls to get you started.