1. The appearance is divided into outer frame, inner frame and functional parts. The inner and outer frames of the key switch are made of PC material. The scientific name of PC material is polycarbonate, commonly known as bulletproof rubber. It has the characteristics of flame retardant, anti-distortion, impact resistance, not easy to dye, and has a smooth appearance. A good part is a functional part. If 80% of the white ones are PC, if they are black, you should pay attention to asking the shopping guide. Since the PC materials are all white, of course, it does not add black yeast.
2. Then the function piece inside has to be opened to see it. After opening the function piece, there is something like a seesaw inside. We call it a seesaw. Usually good switches are rockers without sliding. It is a sliding rocker. There is a silver-white contact at one end of the rocker. Touching the key switch is to rely on him to turn on and off the current. Good switch contacts are all silver alloys, some are silver-nickel alloys, and some are silver-chromium The purpose of the alloy, no matter what alloy it is, is to enhance the hardness of silver and increase its melting point to avoid melting silver when the current is too large; and the rocker is a current-carrying member, which is used to carry current, and its raw material is tin phosphor bronze. Yes, you can also ask the clerk, if he says it's brass, don't buy it. Some of this is because of the layout inside, you can't see it when you buy it, so let me tell you, you can ask the clerk. .
4. Look at its wiring method. Now the best wiring method is the fast wiring method. The card wiring method is used, that is, the wire is stripped out without screws, and it can be directly inserted into the wiring hole behind the switch. Now, we may think that this is nothing, it has no connection with the user, it is only convenient for the electrician, but the wiring method can detect the electrical safety of the switch. It can be seen that when you turn the switch over and see what stands out from the back, it is the functional part. There are several holes behind it. If you look through the holes, if you see a screw and a small board on one side There are also two holes, and there are marks of a few millimeters to a few millimeters around the holes, which proves that this is the layout.
Key switches are mainly used in the color TVs we often use, the audio equipment we often see and use, and we often watch The audio recorder we received, the cameras we used, the computers we used in our office, the game consoles that can be seen in the game arcade, the fax machines used by the company, the walkie-talkies used by security, the company's printers, copiers, and machine tool control equipment in the workshop , some meters, and some household appliances that we use in our homes.
