Common signal interference factors and solutions of LED splicing screen
As the best terminal display equipment in the security industry, LED splicing screen has attracted much attention in the market. With the maturity of splicing technology, the application field of LED splicing screen has been continuously expanded and has now spanned entertainment, government, venues, transportation, energy, finance, In various industries such as radio and television, we can often see LED splicing screens in our daily work and life.
When the LED splicing screen is interfered by the signal, it will have a significant impact on the display of the splicing screen. For example, when the large screen is disturbed by static electricity, there will often be multiple lines and ripples; when the splicing screen produces several lines with equal spacing Vertical bar interference is usually a fault phenomenon caused by the mismatch of the characteristic impedance of the transmission line.
According to the experience of engineers for many years, the general causes of interference are as follows:
1. The quality of the video transmission line is not good, especially the shielding performance is poor.
2. There is a strong interference source near the system.
3. The fault caused by the short circuit or open circuit between the core wire of the video cable and the shielding network.
4. The fault caused by the mismatch of the characteristic impedance of the transmission line.
5. Space radiation interference introduced by transmission lines.
6. Failure caused by the power supply of the power supply system.
Here is a brief analysis of the solutions when the above factors cause signal interference
1. The quality of the video transmission line. The line resistance of this type of video line is too large, which causes a large attenuation of the signal and also aggravates the fault. In addition, the characteristic impedance of this type of video cable is not 75Ω and the parameters are out of specification is also one of the reasons for the failure.
2. The interference source near the system is too strong. The shielding of the camera can be strengthened, and the pipeline of the video cable can be grounded.
3. The core wire of the video cable is short-circuited or short-circuited. When this kind of failure phenomenon occurs, the LCD video wall often does not have problems with all the signals of the entire system, but only on the number of channels with bad connectors. It can be solved as long as you carefully check these connectors one by one.
4. The fault caused by the mismatch of the characteristic impedance of the transmission line. This phenomenon is caused by the fact that the characteristic impedance and distribution parameters of the video cable of the LCD video wall system do not meet the requirements. This situation can be solved by the method of “starting series resistance” or “terminal parallel resistance”. .
5. Space radiation interference introduced by transmission lines. The solution to this situation is to understand the surrounding environment when the system is established, and try to avoid or stay away from the radiation source as much as possible. When the radiation source cannot be avoided, strengthen the shielding of the front-end and central equipment, and use the steel pipe for the pipeline of the transmission line and ground it well.
6. The power supply problem of the power supply system. There are interference signals superimposed on the normal power supply. In this case, as long as the entire system of the LED splicing screen is powered by a purified power supply or an online UPS, it can basically be solved.