How does the coin machine recognize coins?

Slot machines are equipped with sensors to identify coins.

The metal raw materials of 1 yuan, 5-jiao and 1 jiao coins currently issued in China are all special alloys specially used for coinage. Therefore, when it enters the magnetic field generated by a special high-frequency oscillation circuit composed of inductance and capacitance through the coin entrance, the difference of metal material and volume has a slightly different influence on the inductance, and the change of inductance causes the change of oscillation frequency. Then, by detecting the change of frequency and comparing it with the set value, the type of a certain coin is determined, and then the frequency signal is converted into a voltage signal through a narrow-band frequency selection circuit for output, thus completing the identification of metal coins.

Extended data

Size: The slot of the machine is set according to the standard.

Material testing: mainly depends on electromagnetic characteristics. Because real money uses special mixed metal materials, the magnetic impedance of the materials can be distinguished efficiently through specially designed high-frequency oscillation circuit, so as to identify counterfeit money.

Weight detection: The slot machine has designed a "runway" for coins. Only when the size and density are consistent can they pass through the coil within the specified speed range, and counterfeit money can be easily screened out.

The vending machine technology has been updated and iterated, and the sensing device can sense the number of coins, so the vending machine can calculate the amount of change, thus selling goods and finally completing the transaction.

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