Laptop power supply question

[unwiseowl]

I have to repair the wire of my laptop power supply. Just before the plug, there's a cylinder on the wire, about 30mm long, 12mm dia. What is this? Surge protection, or what?

[Feline]

It's a ferrite "bead" (or "beads") which attenuates RFI (Radio Frequency Interference) which could otherwise get back into your mains socket and cause interference to other devices plugged into the same mains supply. Unless you are using a radio on S/W or Medium Wave (AM) in the near vicinity, it generally doesn't make too much difference as to whether it's there or not - it's primarily there to satisfy some bureaucrat in the EU or he FCC.

OK?

[shuttlebus]

unwiseowl,

Agree totally with Feline, but if you are paranoid, you can probably pick up one in Maplin... Just a couple of quid!

Regards,

Shuttlebus

[unwiseowl]

Thanks for the info! That's what I wanted to hear.