Why should the LED display power supply be grounded? This is related to the working mode of the switching power supply. The LED display switching power supply is a series of methods such as filtering-rectification-pulse modulation-output rectification-filtering and other means to convert AC 220V city power into direct current (DC) 5V DC power supply. A device with stable output.  

 

In order to ensure the stability of the AC/DC conversion of the power supply, in accordance with the national 3C mandatory standards, the power supply manufacturer connects an EMI filter circuit from the live wire to the ground wire in the circuit design of the AC220V input terminal. In order to ensure the stability of AC220V input, all power supplies will have filter leakage when working, and the leakage current of a single power supply is about 3.5mA. The leakage voltage is about 110V. What will happen if the power supply of the LED display is not grounded? Let me give you an analysis and analysis below.  

 

1. The LED display is not grounded, and the leakage current may not only damage the chip or burn out the lamp. If more than 20 power supplies are used, the accumulated leakage current will reach 70mA or more, which is enough to damage the leakage protector and cut off the power supply. This is also the reason why the LED display cannot use the leakage protector.

 

2. If the leakage protection is not connected and the LED display is not grounded, the leakage current superimposed by the power supply will exceed the safety current of the human body, and the voltage of 110V is enough to cause death. After grounding, the voltage of the power supply shell is close to 0 to the human body, indicating that there is no potential difference between the power supply and the human body, and the leakage current is led to the ground.

 

Summary: The main components of the LED display are LEDs and drive chips, which are a collection of microelectronic products. The working voltage of LEDs is around 5V, and the general working current is less than 20 mA. The working characteristics of the LED display screen determine its resistance to static electricity and abnormal voltage or current shocks is very fragile. We must recognize this point and pay enough attention to it in the production and use process, and take measures to protect the LED display. The power supply grounding is the most commonly used protection method for the LED display. In order to use the product safely, the power supply of the LED display must be grounded.