After the mains power enters the power supply, high-frequency noise and interference signals are first removed through choke coils and capacitor filtering, and then rectified and filtered to obtain high-voltage direct current. 

Then, the DC power is converted into high-frequency pulsating DC power through a switching circuit, and then the high-frequency switching transformer is sent for voltage reduction. Then filter out the high-frequency AC part, so that the final output is relatively pure low-voltage direct current for computer use.