How does the vending machine know what coin you throw in?

When using a vending machine, many people will have this question: How does the vending machine know what coin I put in? How does it know whether the coin is real and what is the size of the denomination? 　　Automatic vending machine It is a very precise machine.　　The vending machine is mainly composed of a circuit board, a coin chute, and a coin sorter.　　 When you throw a coin in the vending machine, it will first pass through 2 light sensors, which can measure the size of the coin.　　 Each light sensor is composed of a diode and a sensor that can receive the light emitted by it.　　 will block the light when the coin passes the sensor. By calculating the time that the coin blocks the sensor and the time difference when the light of the two sets of sensors is blocked, the size of the coin can be judged. Obviously, it takes longer for a dollar coin to block the sensor than a 50 cent coin.　　 Then, the coin will pass through two electromagnets, their function is to detect the metal composition of the coin.　　 Specifically, the coin passes through 2 copper coils.　　 There is electric current in these copper coils. According to the basic principles of electromagnetism, a magnetic field is formed around the copper coil, which itself becomes an electromagnet.　　When passing by, a metal coin cuts this magnetic field, which in turn changes the current in the copper coil.　　The effect of different metals on the magnetic field in the copper coil is different. According to the change of the current in the copper coil, the circuit board at the back can determine what the metal contained in the coin is.　　Through the above two mechanisms, the vending machine can calculate the denomination of the coin in less than a second, and then guide them to the corresponding coin slot in different categories.　　 If change is needed, the coin slot will carefully release coins from under the coin slot, ensuring that only one coin is released at a time. So the change sound you hear is a'boom' that needs to be picked up, not a burst of'crack'.　　Okay, then how can the vending machine ensure that the product will not get stuck on the shelf? 　　For the common snake-shaped cargo lane vending machine, there is a spiral spring device behind the bottom of the product.　　 After you press the button, the circuit board under the button will send a signal to one of the 32 matchbox-sized motors behind the shelf to make it run and push the spring cargo lane in front to rotate 360 u200bu200bdegrees forward.　　 This spring cargo lane will push the corresponding goods forward, and the goods will fall down with screams, and pass through a layer of 10 beams of far-infrared light beams like in a large film.　　 If nothing falls through this layer of grating, then the machine has every reason to believe that the delivery was not successful. At this time, the computer will allow the spring cargo lane to rotate forward again to ensure that you will not be scammed.　　 This article is organized by automatic vending machines, the views in this article do not represent the views of this site. Previous article: An analysis of the development trend of unmanned vending machines!