Jul 20, 2017
In life, many things you have already used to. But when the child asks you: "Why are ATM machines all metal keyboard?" "Did you really answer that?"
Today, the knowledge of June to give us popular science, some hidden in the life of small knowledge, learned to quickly find children show off!
1. What are these small cylinders on the laptop's power line?
Modern people almost have a laptop, but have you ever noticed that there is a cylindrical object on the power cord of the pen? You know what it does?
The real name of this cylinder is "ferrite magnetic ring", it is also called "anti-interference magnetic ring" or "absorbing magnetic ring", the main function is to suppress the circuit high-frequency noise and noises.
Its material usually belongs to iron-magnesium alloy or iron-nickel alloy, whenever the high-frequency energy through the magnetic material, it will be converted to heat dissipation.
This anti-EMI element, because of its low price and small size, is often used in the transmission line of 3C electronic products.
Do not say do not know, originally this small cylindrical body has such a big effect! Stop when it's a toy!
2, why the notebook computer power key has a specific logo?
Because the power button is in order to control the Open/shutdown (standby), a specific symbol is used. Do you understand?
3. Why are ATM machines in banks usually metal keyboard?
Knowledge June used to think that the ATM keyboard metal manufacturing, because the metal damage resistance is better, until today I know that the choice of metal is not for this reason Ah!
But because it has the advantage of preventing leaks.
When you press the password with your finger, the temperature of the keyboard is changed. If we take a photo with a thermal sensor after the transaction has just been successful, we can get the password by looking at the photo. (May happen in department stores)
The advantage of the metal keyboard is the high conductivity of metal, temperature changes particularly fast. It is difficult to observe the sequence of color judgments even if someone has taken a picture with a thermal camera.