influence Wuxi Monitoring What are the types of interference
Network HD video camera The widespread application of wireless monitoring devices has promoted the development of higher definition and intelligence. But in practical applications, signal interference has always been an important factor that hinders the rapid development of wireless monitoring technology. Today, we will simply understand the types of interference caused by wireless monitoring signals.
1. Space electromagnetic wave interference
The interference sources of space electromagnetic waves are relatively complex. At present, we can see common wireless monitoring equipment everywhere, such as mobile, China Unicom signal tower, walkie talkie, wireless, etc. These are all transmitted by wireless signals, which certainly interfere with wireless monitoring equipment. For digital wireless monitoring equipment, avoid the signal interference of the surrounding similar equipment or the same equipment. The signal source of this interference signal may be the normal signal source in our system. The receiving terminal may not receive the signal or receive the same signal due to the same or similar frequency, which makes the receiving terminal difficult to identify.
2. Horizontal stripe scroll up and down
This phenomenon shows that the stripes roll up or down continuously, and the stripes are relatively wide. It seems to be interference, but actually it is not caused by external electromagnetic waves. If the stripes are ignored, the image is clear. This phenomenon basically accounts for more than 80% of the image interference. It can certainly be said that the problem is the ground potential, which means that there is a potential difference between the ground of the front-end equipment and the ground of the central control room. This problem cannot be tested by a multimeter. If the measured number is zero, it does not mean that there is no potential difference. The only way is to disconnect its circuit, that is to say, disconnect one at both ends (select the front end). If the ground at both ends does not want to be broken, for fear of affecting lightning protection, a ground isolator can be added to solve the problem. This kind of equipment is passive equipment. As long as it is connected in series at any end of the coaxial cable, it is easy to install and has good effect, and can completely eliminate this stripe phenomenon.
3. Meshed interference
The main form of mesh interference is that the image quality is very poor, sometimes absent, which will also lead to the screen crash. This phenomenon is due to the broken or short wire core and shield of the cable. This situation mostly occurs in the joints, and some of them are not well constructed during wiring. The interference caused by welding problems or poor quality of connectors also accounts for a large proportion in the project.
4. Obstacle blocking interference
Obstacle interference in the transmission environment not only blocks the microwave wireless signal, but also absorbs the electromagnetic energy and generates weak current to discharge. Therefore, the barrier of large metal objects in the home environment of wireless signal is the floor with steel mesh inside, and the signal in this direction is almost impossible to penetrate. To be able to penetrate, the signal is also very weak.
