How does the vending machine identify the face value of the invested money?

When you throw a coin into the vending machine, how does it determine the size of the coin? How does the banknote determine the denomination? And how is it achieved? 　　Coin detection is mainly carried out from three aspects: size, material and weight.　　 Needless to say the size. Counterfeit banknotes cannot pass this pass.　　Material testing relies on electromagnetic characteristics, because the coin uses a special mixed metal material, coupled with a specially designed high-frequency oscillation circuit, can more effectively distinguish the magnetic impedance of the material. In order to filter counterfeit banknotes. In addition, there is a small mysterious machine. The magnetoresistance of the coin is also related to the size, and the phase change size test has been completed.　　The weight comparison is more interesting. The vending machine is designed with a coin's 'trackOtherwise, it is false.　　 But there is one more thing: coin making is really tiring. If you don't have a big channel, you have to spend a little money. With channels, we must seize them. I don't know how much gross profit each coin needs to make a stable profit? 　　 Recognizing denominations and authenticating banknotes can be done at the same time.　　 There are dozens of identifiable features in most domestic and foreign banknotes, including various watermarks, various embedded materials, various pattern details, various concave-convex engravings, and various fluorescent patterns. At the time of recognition, the basic recognition methods include size recognition, pattern recognition, optical recognition, magnetic recognition, etc. Nowadays, currency detectors generally select some of the characteristics to recognize. If the recognition is successful, the authenticity of the banknote will be determined. If you know it, you will know the denomination.　　 This article is organized by a vending machine, and this article does not represent the point of view of this site. Previous article: What are the factors that affect the profitability of operating a vending machine?