What impact will EMI filtering circuit have on PC power supply and other PC hardware?

The EMI filtering circuit in PC power supply is essentially a low-pass filter, which can filter out high-frequency impurities in the input mains power and only allow pure 50Hz AC power to enter the subsequent rectification and voltage regulation circuit. At the same time, it can also reduce common mode and differential mode interference in the mains power supply, further improving the purity of the input current to ensure the stable operation of the power supply.

A counterfeit power supply without EMI filtering circuit is equivalent to having no protection at all

In addition, the EMI circuit of the PC power supply can also protect the power supply. The MOV and NTC in the EMI filtering circuit can suppress the sudden voltage and current in the mains input, avoiding the subsequent circuit components from burning out due to voltage or current surges. It can be said to be the first line of defense for the PC power supply and even the entire PC.

Normal power products have complete primary and secondary EMI filtering

In addition, the EMI filtering circuit can also suppress the EMI electromagnetic interference emitted by the power supply itself. Due to the fact that electronic systems, including various high-frequency signal lines, pins of integrated circuits, and connectors, can become radiation interference sources with antenna characteristics, emitting electromagnetic waves and affecting the normal operation of other systems or subsystems within the system, the power supply will also radiate electromagnetic waves to the outside during normal operation, which may interfere with the normal operation of other PC hardware. At this time, the EMI filtering circuit can reduce the EMI of the PC power supply, thereby protecting other PC hardware from interference.

At the same time, due to the fact that EMI can also propagate through wires, it can enter the power grid along power lines from within the power supply, thereby affecting the operation of other electronic devices in the grid. EMI filtering circuits can also suppress the impact of PC power on the grid, ensuring that they do not pollute the grid.

Therefore, when choosing a PC power supply, it is very important to choose a product with a complete EMI filtering circuit. On the one hand, it can ensure the stable operation of the power supply itself, and on the other hand, it can ensure that the power supply will not affect the normal operation of other hardware.