How Do Vending Machines Detect Fake Coins? This machine can decipher coins with pinpoint accuracy. Light sensors measure the size while electromagnets detect the metal type of the coin. Facebook Prev Article Next Article Discover Checkout these cool gadgets... Related Posts No Matter What Trump Says, Your Gadgets Will Still Be Made in China The Truth About Photographic Memory What Would Happen If You Placed Your Hand In The Large Hadron Collider? Light Flashes on The Moon We Still Can’t Figure Out What Your Doctor Will Look Like In The Future If Global Warming Is Real, Why Is Antarctic Ice Growing?