Button switches are divided into two categories: the button switches that use metal reeds as switch contact pieces, with small contact resistance, good hand feel, and a "tick" crisp sound. A switch that uses conductive rubber as a contact path is habitually called a conductive rubber switch. The switch feels good, but the contact resistance is large, generally 100-300n. The structure of the key switch is to move down by the key, so that the contact reed or the conductive rubber block contacts the solder tab to form a path.
 |
 < /td> |
 td> |
| High temperature SMD self-locking key switch | Multifunction five-way key switch | Dustproof and waterproof key switch |
 |
 |
 |
| Patch waterproof touch key switch | Smiley Side Key Switch | Waterproof 6*6*H key switch |
Key Switch Principle< /strong>
The principle of the key switch is through our manual button. Squeeze it down, and then adjust it through the internal structure of the switch. The principle of closing the power supply and making the current turn on or off is also very convenient in production. Therefore, the cost of the key switch is not very high, which is one of the reasons why the key switch is used more.
Key Switch Structure
The key switch is generally composed of a handle, a slide plate, a movable contact piece, a fixed terminal, a compression spring, a shell, etc. It controls the movable contact and the fixed terminal by pressing the switch handle Turning on and off of contacts. There are two types of key switches: single key type and multi-key combination type. The single-button key switch is generally used as a power switch in a TV set, and it is divided into a self-locking and self-resetting type (this switch is pressed once to turn on self-locking, and then pressed again to disconnect and reset) and a non-locking type (no lock). Lock, connect when pressed, reset when released) two structures. How to tell if a key switch is good or bad
1. The appearance is divided into outer frame, inner frame and functional parts. The inner and outer frames of a good key switch are made of PC material. The scientific name of PC material is polycarbonate, commonly known as bulletproof glue. , It is not easy to dye, and the appearance is smooth. Generally speaking, you can see that the outstanding part behind the switch is the functional part. If it is white, 80% are PC. If it is black, you should pay attention to asking the shopping guide. The ingredients are all white, of course, do not remove the black yeast added to it.
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 I'll say something, you can know it by asking the manufacturer. .
3. If the hole of the socket is seen from the outside, if there is something black or white covering the copper sheet that cannot be seen inside, then it proves that there is a maintenance door layout, and you can take a hairpin or something hard and poke it against the single hole, but you can't get in. It proves that there is a self-locking device, which is a good socket. If there is no maintenance door, you must not buy it. The so-called maintenance doors of the brand are all plastic, and the products are all reinforced nylon, which is fireproof and durable. There are maintenance gates to keep children from being cunning when the barrel switches. This is very important.
4. Look at its wiring method. The current wiring method adopts the fast wiring method, and 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, there is no connection with the user, just the convenience of the electrician, but the wiring method can detect the power consumption of the switch, don't neglect it; we can also use the general double-hole pressure plate layout, which can be seen from the appearance. It can be seen that you turn the switch over and see that there are some prominent parts on the back, that is, the functional parts. There are several holes behind it. If you look through the holes, if you see a screw and a small board on one side, it is still there. There are two holes, and there are markings of a few millimeters to a few millimeters around the holes, which proves that this is the layout.
