The magnetic ring’s ferrite bead is an inductor that can form a passive low-pass filter, then attenuates high-frequency interference. Whether the device itself flows out or externally accessed, the energy of the high-frequency signal is absorbed by the ferrite core and converted into heat to be dissipated. Therefore, the magnetic bead is used in the USB signal cable of the keyboard and mouse to shield the high frequency signal. If there is no shielded wire, the USB data cable will absorb the high frequency signals generated by the surrounding environment or the hardware inside the chassis like the antenna, thus affecting the actual transmission. Therefore, adding a magnetic ring is a more economical solution.
So the role of the magnetic ring is still very large, then the quality of the peripheral cable must be judged according to whether there is a magnetic ring? However, for 1-2 meters USB data cables, the use of magnetic rings is to prevent external high-frequency signal interference, and the effect of shielding high-frequency signals can be achieved by using shielding. So carefully designed data cables can be used to meet daily needs, magnetic ring is an additional role, and can not be used as a standard for judging the quality of USB data cables!
