We might be taking our laptop charger cables for granted. Sure, we love how they charge our much needed and loved devices like our mobiles and tablets but besides that function we don’t know how much work went into the cord.
One component of the charge cable is the small cylinder-like module. Usually this part is near the end of the cable. You will be surprised to find out what this unassuming piece does. Let’s just say this piece plays an important role in protecting your devices from slowly deteriorating.
Many people have this small cylinder on their laptop charger, yet no one has really investigated or asked what it is.
It turns out the little cylinder part on the laptop charger is called a ferrite bead. It’s extremely important in keeping your laptop running.
All of the small parts inside your laptop run because of radio frequencies. Your casing that holds everything together, stops them from interfering with each other. The charging cable attached to your laptop acts as antennae, broadcasting your laptop’s vibrations as radio frequencies and picking up signals which creates interference. So the cylinder, or ferrite bead, prevents interference between your electronic devices.
What this small cylinder on your laptop charger is for
This small cylinder is called Ferrite Bead. This is an electric choke basically and functions to isolate the laptop from electro-magnetic noise which arises out of the waves picked up by the cable, or from the noise in AC-DC converter.
It drive away high-frequency currents in a ferrite ceramic, and helps make the most powerful noise suppression device. And it is also known as EMI ring.
It is important because in its absence a circuit is very much likely to break down.
What is Ferrite Bead?
In a typical computer system found in a home or office, you normally see these “bumps” on the mouse, keyboard and monitor cables. You can also find them on power supply wires when a device (like a printer or scanner) uses an external transformer.
These “bumps” are called ferrite beads or sometimes ferrite chokes. Their goal in life is to reduce EMI (electromagnetic interference) and RFI (radio-frequency interference).
A ferrite bead is simply a hollow bead or cylinder made of ferrite, which is a semi-magnetic substance made from iron oxide (rust) alloyed with other metals. It slips over the cable when the cable is made, or it can be snapped around the cable in two pieces after the cable is made. The bead is encased in plastic — if you cut the plastic, all that you would find inside is a black metal cylinder.
Computers are fairly noisy devices. The motherboard inside the computer’s case has an oscillator that is running at anywhere from 300 MHz to 1,000 MHz. The keyboard has its own processor and oscillator as well. The video card has its own oscillators to drive the monitor. All of these oscillators have the potential to broadcast radio signals at their given frequencies. Most of this interference can also be eliminated by the cases around the motherboard and keyboard.
Another source of noise is the cables connecting the devices. These cables act as nice, long antennae for the signals they carry. They broadcast the signals quite efficiently. The signals they broadcast can interfere with radios and TVs. The cables can also receive signals and transmit them into the case, where they cause problems. A ferrite bead has the property of eliminating the broadcast signals. Essentially, it “chokes” the RFI transmission at that point on the cable — this is why you find the beads at the ends of the cables. Instead of traveling down the cable and transmitting, the RFI signals turn into heat in the bead.