Naked Science Forum

On the Lighter Side => Science Experiments => Topic started by: Going2try on 25/11/2014 03:28:41

Title: Building a tube magnet ?
Post by: Going2try on 25/11/2014 03:28:41
I'm new to the forum and am not sure if this question has ever been addressed . I need to build a tube electromagnet 2" x 1' for a small project I'm doing. I need to know what size wire I will need to use to wind it with, I want the magnetic charge to be quick, powerful and be constant so the wire will need to be able to handle the current for a long period of time, I also need to know what type of material to use for the tube, can I use stainless Steel,conduit or other non magnetic material or will that not work for this application, any information would be greatly appreciated.
Title: Re: Building a tube magnet ?
Post by: RD on 25/11/2014 03:31:46
Quicker and cheaper to buy something already containing one ...

http://www.greenweld.co.uk/acatalog/Shop_Solenoids_237.html

http://www.ebay.co.uk/itm/2-x-OMRON-MY2NJ-J-MY2N-MY2-DC-12V-8PIN-Power-Relay-Coil-DPDT-5A-HH52P-L-/161317570675
Title: Re: Building a tube magnet ?
Post by: CliffordK on 25/11/2014 06:46:59
I was imagining something more like the Shake Flashlights (http://www.amazon.com/Forever-Light-Shake-Flashlight/dp/B000BPJ262) which turn out to not be quite as effective as advertised.

There are a lot of variables.  Are you using your tube magnet in conjunction with a permanent magnet?  How powerful?  What are you making?  Oh, and your target voltage/amperage? 

Your core material may depend on whether you choose to periodically reverse the magnetic field (AC), or if it will always be the same direction of field (DC)
Title: Re: Building a tube magnet ?
Post by: alancalverd on 25/11/2014 09:20:29
If you want a really fast risetime, don't use a conductive former. Plastic conduit or drainpipe is excellent. I have made demonstration solenoids with single-strand 0.5 mm varnished copper wire - it holds its shape better than regular plastic-covered wire.

But you really need to start with a specification: what field strength do you want? Do you have the skill to wind a multi-layer solenoid, or just a single coil? What power supply do you have available? It's an interesting balancing act between risetime (the fewer turns, the faster the risetime), current capacity (fewer turns = more current for the same field, but you will need thicker wire to carry the current), and heat dissipation (pulsed or continuous field?)