Therefore, the cables have a plastic cylinder at the end of
Oct 01, 2019
In many cables, for example, to load cables of Laptops, is at the end of a plastic cylinder. This is a so-called interference filter, or sheath wave filter. We will explain in this article, what this Filter is and how it works.
Plastic cylinder at the end of the charging cable To the EMI filter is used
A device, such as, for example, a Notebook computer, generates electromagnetic waves. These waves are sent from the charging cable and to the environment. The cable works very similar to a radio antenna.
These so-called sheath waves to interfere other electronic devices or the Wi-Fi on, if it transmits on the same frequency (wavelength).
Now the EMI filter comes into play: It cancels out the electromagnetic waves, before they can be reinforced via the cable. How this works, read in the next paragraph.
How does a sheath wave filter?
A sheath wave filter in the simplest case of a ferrite core. Ferrite is not or barely electrically conductive Material.
Through this ferrite core to the cable. The ferrite absorbs the electromagnetic waves and provides for filtering.