Right, take a look at your computer. It has a couple of leads going into the back of the screen, and one of the leads probably has something that looks a little like this picture… Looks pretty normal, right? Well, ask someone what the black cylindrical object is for and the answer will always be ‘I have no idea’. Well, I’m about to tell you exactly what it’s for. Make sure you remember for the next pub quiz you go to… This little piece of plastic is called a Ferrite Bead. Inside the plastic coating is a magnet with a wire running through it. It looks a little like this… Something else you might not have known is that any long wire is essentially an antenna. It naturally acts as a receiver and transmitter for radio waves, and this is bad news for two reasons.
- The device or power source that is connected to the wire may cause variations in the electrical flow of the wire. These variations could cause the wire to transmit radio waves and these waves could in turn interfere with nearby devices.
- Conversely, nearby devices could produce radio signals (intentional or otherwise) that get picked up by the wire. These signals could vary the electrical current in the wire which could in turn interfere with the connected devices.