Principle and practical use of magnetic rings

Ferrite bead is a kind of inductor, can form a passive low-pass filter, can attenuate high-frequency interference, both outflow from the device itself and outside into the world, and high-frequency signal energy will be absorbed by the ferrite core is converted into heat emitted.

Magnetic ring for keyboard and mouse USB cable is to shield the useless high-frequency signals, because the USB cable is usually very close to the computer chassis, if the cable does not have a shielding layer, the USB cable will be like an antenna to absorb the high-frequency signals generated by the surrounding environment or hardware in the chassis, thus affecting the actual transmission. Adding a magnetic ring is a more economical solution.

The "pimple" on the USB cable: so useful!
Magnetic rings do guarantee the quality of signal transmission

Do I need a magnetic ring?

Since the magnetic ring has a considerable role, then judge the peripheral cable is good or bad must look at the magnetic ring this point?

This is not the case. For 1-2 meters of USB cable, the use of magnetic ring is more to prevent external high-frequency signal interference, and through the use of shielding layer can also achieve the effect of shielding high-frequency signal interference, so the choice of USB cable simply by the presence or absence of a magnetic ring to judge too sweeping, is not very reasonable, well-designed USB cable to meet the daily use of USB data.

Translated with DeepL