Magnet question

bluey

mmmm!very interesting. I will check it out when I'm feeling a bit better, I just broke a bone in my foot aaaaagh!

zoobyshoe

Wow. Better get that taken care of.

bluey

Ive taken a painkiller an anti inflammatory and Ive got my foot elevated on a cushion, I wont be using magnets to try and cure it that for sure.LOL

Robin07

It doesn't shield it, its redistributed. So the field is no weaker, its just being bent around again. Look at http://en.wikipedia.org/wiki/Halbach_array this redirects the field very effectivley. A fridge magnet does the same to a much weaker extent. The HD mags can be taken off by simply twisting the ferrous plate. You will then find that the magnet is just as strong of either side and the plate is still not magnetic. Very interesting plate material for being so thin.

zoobyshoe

No, a hard drive magnet with plate attached has nothing to do with a Halbach array.

Momento

So if there is an energy source... It won't be temporary?
If it were temporary it could last a long "temporarly" time

bluey

If it is not an halbach array causing this effect then what is it? Is the shield magnetized in sections to get the effect? This is getting confusing.

zoobyshoe

A halbach array has no shield. It's a bunch of magnet segments cleverly arranged and glued to each other so one pole dominates and the other is suppressed.

A harddrive magnet with a shield on one side is doing something different. The magnetic flux from north to south is contained within the shielding material on one side and allowed to project out into space on the other.

A halbach array presents one pole on one side of the array and no pole on the other (it's there, just suppressed), a HD magnet with shield presents two poles on one side and two "contained" poles on the other.

The point of a A halbach array is to kind of "fake" a magnetic monopole, a thing that doesn't actually exist. The HD magnet with shield has two frank poles, there's no attempt at a monopole.

bluey

I now know what an halbach array is but the crux of my question is,what properties of the shielding material is causing this effect,how does it contain the flux?

zoobyshoe

I don't know how it contains the flux. All I can tell you is that it is a property of magnetic flux that it 'prefers' to concentrate itself in magnetic metals rather than space.

http://en.wikipedia.org/wiki/Magnet_keeper

bluey

I think I have it worked out? The so called shield doesn't have any special properties at all, it is really a simple bracket/short circuit device,instead of shorting electricity, it is shorting the magnetic field close to the magnet so that it cant go out into space.

zoobyshoe

That's pretty much it, yep.