What’s Inside? TheGreat Mystery of theTiny Cylinder in LaptopChargers Solved

I can’t say it’s really bugged me, but
it’s always seemed strange that there
is a bulge in my laptop charger right
after the charger connects to the
laptop.


 It can’t be an aesthetic decision
to put a bulge in the middle of a
streamlined piece of hardware and it
certainly wouldn’t save money to add
extra weight to the machine (building,
raw materials, shipping costs would
increase), so why does the charger
have that little cylinder preinstalled?
Well the answer is quite simple actually.



Every device that transports energy or
deals in the transfer of energy gives off
and picks up energy from different
sources. The energy generated from the
socket that powers your laptop is just
enough to transmit radio waves.



Also,
the laptop charger that transports all
that energy can also pick up radio
waves of that frequency. All of this is
called Electro-Magnetic Interference
(EMI).

So, of course, to reduce energy
loss and white noise from random radio
waves swimming around in the air, one
needs a filter, the little cylinder.



It’s called a Ferrite Bead, an EMI filter
or a Ferrite Core. It is specifically built
to ward away radio waves and prevent
energy loss of the same type from
within the charger.


This makes the
charger much more efficient and helps
charge your computer more quickly.



And you may have noticed that
the Ferrite Bead is covered in what
seems to be plastic casing.

 That’s just
to protect it from damage. Of course
there are ways to avoid the need for
the Ferrite Bead but since it is
relatively cheap to purchase and
increases efficiency, it’s a welcome fix.