What are these things and what do they do?

Psean

What are the little thingies on the leads of some power supplies? Can I cut it off if I want to get rid of some excess length in the lead or does it do something important? (my guess is the latter but it would be handy to neaten things up with a shorter lead)

nick

Probably a neodymium magnet of sorts to stop interferance, can safely lob it off

Heath

actually a ferrit bead , used to suppress high frequency noise . you can safely cut it off

Psean

Will the interference not add noise into the system? It's the PSU for my pedals

nick

Psean wrote Will the interference not add noise into the system? It's the PSU for my pedals

I removed mine off my PSU and havent noticed any.

Psean

Thank nic.
You also have the one from Mantech right? I might just do the same then.

nick

Psean wrote Thank nic.
You also have the one from Mantech right? I might just do the same then.

Yip, same one ?

Psean

Cool?

AlanRatcliffe

Ferrite beads are used to suppress high frequency and radio interference. They are usually needed on a cable coming from any switch mode supply.

Psean

Alan Ratcliffe wrote Ferrite beads are used to suppress high frequency and radio interference. They are usually needed on a cable coming from any switch mode supply.

Thanks Alan. So will cutting it off lead to a noticeable amount of interference and make it noisy? I'm really not clued up on this stuff, but occasionally particularly with my wah (which I've been running on a battery until recently) in an open position I pick up radio through my amp. Will removing the bead make it worse? As Nick says, he's removed his and there's no noise. But radio interference?

AlanRatcliffe

I think it depends on the circuit you are plugged in to and how susceptible it is to interference. I generally assume that if the manufacturer thought it was necessary to add a ferrite bead, the chances are there will be a situation where it is needed so it is safer to leave it intact.

Psean

Thanks. The wiring in parts of my house is old and susceptible to interference (I'm also not too far from SABC so I think that adds to it). I'll keep it then.

SnapcaseZA

Yip, they are ferrite beads. They are there to reduce interference/emissions, but not only into your device, but from your device into the mains of your home or wherever. Its called conducted emissions, so what your circuit pumps out over conductors (mains wiring). This is different to radiated emissions which is what EMC fields your circuit pumps into the air. There are obviously standards that electronic equipment must pass before it can be sold in many areas of the world....and you probably find that power supply failed those without the bead....