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Discussion board help and admin topics => Half Baked Ideas => Topic started by: AnotherNewbie on December 01, 2008, 08:54:34 PM

Title: help with an electromagnet
Post by: AnotherNewbie on December 01, 2008, 08:54:34 PM
HI,

I want to build an electromagnet, but I don't know how to determine the parts.

Can someone help me with the construction details?

I have a 2000 Gauss, 1 inch round permanent magnet. I want to duplicate the 2000 Gauss strength in an electromagnet with a 3/4 inch diameter, 2 inch length solid metal core.

The questions are:

What kind of metal should the core be? (I want minimum remanence)
What kind of wire should I use?
What gauge winding wire should I use?
How many turns do I need to make?
What other information do I need?
How do I find out how many watts are needed to make it work?

Have a good one all.

Thanks
Title: Re: help with an electromagnet
Post by: brian334 on December 01, 2008, 09:14:19 PM

I have a 2000 Gauss, 1 inch round permanent magnet. I want to duplicate the 2000 Gauss strength in an electromagnet with a 3/4 inch diameter, 2 inch length solid metal core.

Who are you and why did you post this?
Title: Re: help with an electromagnet
Post by: AnotherNewbie on December 01, 2008, 09:22:12 PM
I posted it because I don't know the specs on how to make an electromagnet like I want. This seemed like a place where I could get this information. Am I wrong?

I am someone messing around with magnets and electromagnets, like a lot of others. Are you asking me for my name, address and phone number?
Title: Re: help with an electromagnet
Post by: nievesoliveras on December 01, 2008, 09:56:40 PM
@newbie

If you want to make a strong electromagnet check this topic:
http://www.overunity.com/index.php?topic=5929.0;topicseen

Jesus
Title: Re: help with an electromagnet
Post by: AnotherNewbie on December 02, 2008, 01:34:21 AM
Quote from: nievesoliveras on December 01, 2008, 09:56:40 PM
@newbie

If you want to make a strong electromagnet check this topic:
http://www.overunity.com/index.php?topic=5929.0;topicseen

Jesus

Thanks Jesus,

I read every post in that thread, unfortunately I still don't know what gauge wire to use or the number of turns. I do have a better grasp about materials, but again there was no conclusion on what was best.

Little by little I am learning what I need to know.

Thanks for the help.

Title: Re: help with an electromagnet
Post by: capthook on December 02, 2008, 03:03:53 PM
A close approximation:

(1) H in Oersted= (.4 x 3.14 x N x I)/coil length in cm

(2) B in Gauss = (H x (core permeability x 0.00000125664)) x 10000

So if 2,000 Gauss needed with core permeability of 800u:

H= 2000/10.05312 = 199
(rearrangement of  (2))

H = (.4 x 3.14 x N x I) / 5.08 = 199

N x I = (199 x 5.08) / 1.256 = 805 ampturns

So you could use:

N x I = 805 turns x 1 amp = 805 ampturns

805 turns of #22 AWG = 8.3 ohms
I=V/R : 9volts / 8.3 ohms ~ 1

So 805 turns of #22 AWG at 9 volts on a 800u permeability core (1010 steel) will achieve a close approximation of around 2000 Gauss.