We will find Laptops have cylinder thing on the charging card. What is it? And more importantly, why don’t Mobile (Android or iPhone) products have them?
In a typical everyday computer or digital system you use in a home or office, you normally see these cylinder “bumps” on the laptop charging cables, keyword cables, and monitor cables, even in some high tech mouse cables.
These “cylinder things” are called ferrite beads or EMI filters. Their purpose is to reduce RFI (radio-frequency interference) and EMI (electromagnetic interference)
Which in layman’s term, they acts as filter and reduces unwanted noises.
Because a cable may transmit any noise generated by the device, all the tiny moving parts in the laptop’s hard drive, video card and etc. they are capable of producing radio frequencies to the external world, or pick up existing noise. This is undesirable it is a cost-effective way to prevent interference between your many great electronic devices sending receiving noises.
Now you wonder why your phone’s charging cord doesn’t have one, because they don’t need one because simply put they have less moving parts.
It is a small thing with a big role, now you know why.