What Is That Small Cylinder On My Computer Cables?

Do you know what’s that tiny cylinder towards the end of your laptop or monitor cable? It’s a ferrite core that’s used to reduce the electromagnetic interference from the cable, which acts as an ‘unintentional’ antenna, and other devices. The atoms in the core align in such a manner that they cancel the noise. Cables of many modern devices don’t have these lumps as they might’ve incorporated the fixes inside the device itself.

The digital era has gifted us many gizmos to make our lives more interesting and easy. Just like everybody else, I use many electronic gadgets in daily life. More I explore these gadgets, more I get to learn about them. Similar desires of Fossbytes readers have made our Explainer section very popular.

In the same section, a few days ago, I told you about what causes a battery explosion. Today, I’m going to tell you about a small mysterious cylinder found on many cables–particularly the older ones. I noticed one on my laptop and monitor cables. This lump is usually found on one side of the cable.

So, what is this small cylinder on these cables? What’s its use?

This small cylinder on these cables is a ferrite core, also called a ferrite bead or ferrite choke. It’s simply a hollow cylinder that’s made of ferrite (iron oxide alloyed with other metals), which is a semi-magnetic substance.

Wondering what’s the use? Its purpose is to reduce the electromagnetic interference (EMI) and radio frequency interference (RFI).

Such interferences cause our electronic devices to buzz, speakers to chirp, and monitors to flicker when they are too near to cell phones or other devices.

Our cables can act like an ‘unintentional’ antenna that broadcast or pick interference/noise. These cylinders in cables are made in such a way to reduce the interference with other electrical devices. In the cylinder, these signals get converted into heat. The ferrite’s atoms align themselves in different directions and block EMI.

Thus, the ferrite core prevents the disturbance and improves the quality of data stream.

But, why do some cables, e.g., cables of Apple’s products, don’t have these cylinders? In many new products, we don’t see this cylinder as it’s possible that the fixes may be already incorporated internally.

So, did you find this Explainer on ferrite beads interesting? Do you know some other interesting technology facts? Don’t forget to share your views and feedback.