Miner protection box

1. There are several kinds of antenna feeder joint protection boxes, which are used for waterproof protection of feeder joint. There are four models commonly used in China. 1: The antenna connector protection box is used for the protection of 1 / 2 jumper and antenna connector; 2: Feeder connector protection box is used for the protection of 1 / 2 jumper and 7 / 8 feeder connector; 3: Feeder grounding protection box is used to protect 7 / 8 feeder grounding wire. 4. TD-SCDMA special protection box is used for the protection of 1 / 4 or 3 / 8 feeder and RRU connection connector and antenna connector. This one is for mobile. At present, the domestic operators are mostly made by 3M, and the price of a set (antenna joint protection box + feeder joint protection box) is about 150 yuan per month. 3M only has these two procts, while other models do not. The quality of domestic manufacturers is uneven. Most of them say they are made by themselves. In fact, they have no entity, including the link of the downstairs answer. If you look at his answer carefully, you will find that there is a FG series protection box called Fook optoelectronics, which makes it unclear whether the protection box is made by Huamai or Fook optoelectronics. At present, the domestic manufacturers are mainly concentrated in Zhejiang, Jiangsu and Beijing. The protection boxes of most manufacturers are soaked in water at a depth of 1 meter, and the 24-hour test is water leakage, let alone high and low temperature test. Only one manufacturer in Ningbo and Beijing has passed the test, so please be careful when you cooperate with the manufacturer of the antenna feeder protection box. First, you should understand the qualification of the manufacturer, and then look at their cooperation records with the operators. The most important thing is to test their procts. Don't be superstitious about the website of the cheater company. Some companies' websites look like human models, In fact, the real company is just a few square meters of small black house.

2. Must add protective cover, there is no hard and fast regulation, but if you don't add protective cover, the project acceptance will be unqualified.

3. In the quality of mobile communication network, the reliability of antenna feeder system accounts for 30% - 50% of the reliability of the whole base station system. The most common problem of feeder system is that the connector is not well sealed, which will cause the standing wave ratio alarm and affect the normal operation of the base station. There are many problems in the traditional sealing method, such as time-consuming and laborious operation, general waterproof and moisture-proof performance, easy aging and so on! The FG series new antenna feeder protection box launched by Fook optoelectronics has been inspected by the quality supervision and inspection center of Posts and telecommunications instry of the Ministry of information instry, and all indexes meet the requirements
Proct characteristics
all indexes have passed the inspection by the Ministry of information instry's proct quality supervision center of post and telecommunications instry
after a long time of temperature cycling inspection from - 30 ℃ to 50 ℃
after the flattening inspection under the pressure of 800N / 10cm
after the impact inspection of 1kg steel ball 1m high under low temperature and normal temperature
the protection ability is outstanding, It can completely replace the waterproof tape
to complete the connector sealing in 5 steps with one hand, simplify the work at height
difficulty and rece the working time
it has a service life of more than 10 years, can be reused, has high cost performance ratio and is easy to operate, and is suitable for all kinds of harsh environments

4. The card reader is used to enable the computer to read things on the memory stick. It needs to be connected to the computer before it can be used. The protection box is a box to protect the PSP, which can be installed inside

5. The attendance system prompts: generally, this is original, which is configured in the factory (additional charge). If it is later configured, you can find suppliers or machine manufacturers to buy it directly. Many commonly used models also have protection boxes on Taobao. It's really inconvenient to buy them. You can also find someone to do it yourself.

6. Pry the knife open

7. You're talking about the built-in waterproof cover. The black part at the top is lifted up by the camera. It's very strong.

8. Quick break protection and over-current protection are current section I and current section II protection; The difference between the two protections is that the over-current protection is set according to the maximum load current at the end of the line, while the quick break protection limits the protection scope by increasing the setting value of the over-current protection; In this way, if the line fault occurs in the near end of the power supply, the quick break protection trips before the over-current action, and the action time is less than the over-current protection; The faults at the far end of the power supply are all tripped by the over-current protection. Quick break and over-current are displayed in the setting of protection device as current section I and current section II. In my understanding, this is similar to the setting of 110kV distance section I and II.

9.

You can find out what static electricity is and what substances proce static electricity The picture of electrostatic floor grounding resistance protection box is a simple one

Matter is made up of molecules, which are made up of atoms, in which there are negatively charged electrons and positively charged protons. Under normal conditions, the number of protons and electrons of an atom is the same, and the positive and negative balance, so it shows the phenomenon of uncharged. But the electron around the nucleus, once the external force is out of orbit, leave the original atom and intrude into other atoms B, a atom e to the lack of electron number and positive charge phenomenon, called cation, B atom e to the increase of electron number and negative charge phenomenon, called anion. The reason for the unbalanced distribution of electrons is that the electrons are separated from the orbit by an external force, which contains all kinds of energy (such as kinetic energy, potential energy, thermal energy, chemical energy, etc.) in daily life, any two objects of different materials contact and then separate to proce static electricity

When two different objects contact each other, one object will lose some charge. For example, the electron will be transferred to another object to make it positively charged, while the other person will get some resial electrons to make it negatively charged. If the charge is difficult to neutralize in the process of separation, the charge will accumulate and make the object carry static electricity. So when an object is separated from other objects, it will bring static electricity. Usually, stripping a piece of plastic film from an object is a typical "contact separation" electrification. In daily life, the electrostatic generated by taking off clothes is also a "contact separation" electrification

Solids, liquids and even gases are electrostatic e to contact separation. This is because the gas is also composed of molecules and atoms. When the air flows, molecules and atoms will also "contact and separate" and become electrified

We all know friction electrification, but we seldom hear of contact electrification. In fact, friction electrification is a process of contact and separation, resulting in the imbalance of positive and negative charges. Friction is a process of continuous contact and separation. Therefore, friction electrification is essentially contact separation electrification. In daily life, all kinds of objects may proce static electricity e to movement or friction

Another common type of electrification is inctive electrification. When a charged object approaches an uncharged object, a negative charge and a positive charge will be inced at both ends of the uncharged conctor

In the dry and windy autumn, we often encounter this phenomenon in our daily life: when we take off our clothes and go to bed at night, we often hear crackling sound in the dark, accompanied by blue light. When we meet and shake hands, when our fingers just touch each other, we will suddenly feel the pricking pain of fingertips, which is shocking; When you get up in the morning to comb your hair, your hair will often "float" up and become more disordered. When you pull the door handle and turn on the tap, you will "get an electric shock" and often make a "Pa, Pa" sound. This is the static electricity that occurs in the human body. The above phenomena are the result of external "discharge" of static electricity in the body

[climate]

when the air humidity is low, the weather is dry and the water molecules are few, it is easy to proce

[material]

theoretically, as long as the two sides of friction are compared, one side is easier to lose electrons, while the other side is easier to get electrons, the friction of two different materials can proce static electricity

in daily life, people often accumulate static electricity e to contact and friction with chemical fiber underwear, carpet, cushion and wallpaper. There is a high electrostatic voltage on and around the human body, and the electrostatic generated by the electrical equipment itself also makes the random existence of space electrostatic in the air. According to the calculation of professional institutions, walking indoors may proce 6000 volts, rubbing your butt on a chair will proce more than 1800 volts, and when you hear the crackle, it will have tens of thousands of volts. Generally, when the electrostatic voltage reaches 2000 V, the finger will feel it; When the voltage exceeds 3000 V, sparks will appear, and fingers will feel pain like acupuncture; When the voltage exceeds 7000 V, people feel electric shock

the results showed that, The sequence of friction electrification of different substances is as follows:

+ air → human hands → asbestos → rabbit hair → glass → mica → human hair nylon wool → lead → silk → aluminum paper → cotton steel → wood → amber → wax → hard rubber → nickel / copper → Brass / silver → gold / platinum → sulfur → rayon → polyester → celluloid → olan → polyurethane → polyethylene → polypropylene → PVC → SiO2 → PTFE