Ferrite beads bumps use at the end of Computer cables
Ferrite beads bumps use at the end of Computer cables – Electronic Cables are mostly used to transfer signals, data or electricity. You may have seen a bump at the end of electronic cables of mouse, keyboard, monitors, printer, scanner & others. You may also find them on power supply cables where external transformer is used. What is the use of such a bump at the end of the cable? These bumps are known as Ferrite beads or ferrite chokes. The main duty of beads is to reduce Electro Magnetic Interference (EMI) and Radio Frequency Interference (RFI).
The ferrite bead looking like a cylinder is made up of ferrite, which is a semi-magnetic substance made of iron oxide alloy and other metals. The bead is encapsulated inside the plastic. When you cut the plastic, you will find a black metal cylinder inside it. The ferrite bead is simply slipped over the cable at the time of manufacturing. This substance is very essential and used on many types of electronic cables.
Computer generally make noise while running due to devices attached inside it. The motherboard inside the computer case has an oscillator running continuously between 300 MHZ to 1000 MHZ frequency. The keyboard attached with the computer has its own oscillator. Likewise, video card has also its own oscillators to run the monitor. Since all these oscillators continuously emits radio signal at their own frequency. This will possibly create an interference between those radio signals. So, in order to eliminate such interference, the cases and beads are used.
Similarly, you may have heard noise where cables are used to connect the devices. They successfully carry and broadcast signals. And the signal they broadcast might interfere with the signal generated by radio or TVs. So, in this place ferrite bead will eliminate the radio frequency interference. Alternatively, it chokes the RFI transmission at the ends of the cables. This is the reason why beads gets heated.