Magnet system 1

[tobee11]

Hello - I have attached a drawing of a simple system that I've been working on. I have a plastic base with a neodymium magnet recessed into the top. There are small ridges protruding from the top of the plastic base. A piece of thin steel will be attracted to the magnet and lay on top of the ridges. I was wondering if it is possible to install a small electromagnet on top of the neodymium magnet such that when the electromagnet is activated, it repulses the neodymium magnet and allows the steel plate to be removed. My thought is that the electromagnet can be strong enough to repulse the neodymium magnet, but weak enough to allow the steel plate to be removed with minimal energy.
Is something like this possible? Thanks very much. I appreciate the help.

 

[EdStainless]

it is done all of the time.
it would be easier to recess the magnet further and put a steel pole piece on it, then wind your turns around the pole piece.

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Plymouth Tube

 

[tobee11]

Thank you for the reply. I'd like to add some minor detail and ask a few more questions.

The distance between the top of the recessed magnet and the top of the ridges is small - around 1/8". Can I fit an electromagnet in that small of a space?

Do you know where I can find a micro-electromagnet on small of a scale? Or, is this something I would need to devise on my own?

Thanks again. I really appreciate the help.

 

[FeX32]

take it a few steps further.....rail gun in the face


Fe

 

[FeX32]

just kidding,
An EM that small you cold build yourself. Some insulated copper wire will do the trick.


Fe

 

[FeX32]

just kidding,
An EM that small you could build yourself. Some insulated copper wire will do the trick.


Fe

 

[FeX32]

sorry, accidentally hit the button twice, and in between i caught a "u" in the dust.


Fe

 

[IRstuff]

I think you're referring to a coil gun. A rail gun has no coils, and the current goes directly through the projectile itself.

TTFN

FAQ731-376

 

[FeX32]

Thanks IRstuff. Yes, that was the picture I had in my mind.


Fe

 

[IRstuff]

As far as the EM is concerned, you need to be looking at how strong your magnet is, and if you intend to counter that, then you need to design your EM to nullify the field from the PM. That might be quite non-trivial.

You need to start from the basic requirement, and choose a magnet that does only what is absolutely necessary, and no more. Only then can you be somewhat confident on designing an EM to do its job.

It seems to me that you've pre-chosen a PM without specifically determining whether this neodynium magnet is gross overkill or not. Your one extra degree of freedom will be how much current you can run through the EM, and for how long you need it. Again, that comes from a thorough requirements analysis.

TTFN

FAQ731-376