How to recognize the coin vending machine/working principle?

The vending machine how to distinguish the coin? Want to learn more about automatic coin vending machine related information, consult: first sensing coil to detect the size of the coin, and the electromagnet to detect its material ▼ at the instant of the COINS cast, machine will determine the COINS, classification and put them away ▼ when found strange, counterfeit will be popup ▼ when give you find zero, the machine will be released by COINS ▼ and vending machines is how to ensure that you get your food? Behind the vending machine lock, have a miniature computer, control the motor of the corresponding 132 matchbox size ▼ the motor can drive wheel 360 degree rotation ▼ when food falls off, it will be through 10, the infrared beams without infrared sensing anything, computer sends out instructions to exit the coin ▼ we want more information, please focus on the vending machine network: