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 This Man Is Using Satellite Imagery To Search For A Hidden Nazi Treasure Are Lasers The Weapons Of The Future? NASA Predicts a Mega Drought for America in 2075 How Simple Ideas Lead to Scientific Discoveries Capture 360 Degree Video Around You What Will the World Look Like in 2020?