Hi all,

just a reality check before embarking on tedious winding ....

I need to make a couple of electromagnets for kind of a magnetic
suspension (not levitating, motion damping)

What I'm repelling against are fairly strong permanent ferrite
magnets. These are about 25mm diameter and 6mm thick, with
the poles on the faces

So I first Googled for ideas on construction. After seeing several
people suggesting that strong electromagnets should be U-shaped,
I thought that was the way to go. However, on reflection, that's
probably not what I want. The U-shape has N and S poles at the
ends of the U. Which might be best for attracting metal but seems
to me would be ineffective for repelling another magnet

OK so far ?

What I should be looking at then is more like a solenoid or relay
coil, which will have a pole at each end of the core rod. If so, I've
seen a suggestion that the addition of a permanent magnet to the
opposite end of the core will pre-arrange the domains so that the
energising of the coil will be more effective

Is that something anyone has tried and found to be true ?

TIA

Joe
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