Winding a strong electromagnet

[capthook]

I think you mean 3/16" diameter core which is .4m.

(1) H in AT/m=NxI/length

(2) B in Tesla=H x (.000001256 x 800)

2000 Gauss=.2Tesla  ur=.0010048
.2/.0010048=199 AT/m

H=N x I/5.08    199 x 5.08=1011 AT

So you could use:
N x I=1011 x 1 amp=1011T

1011 turns of 22 gauge wire @ .4 x pi=106 feet  which yields 1.7 ohms

I=V/R    I=1  R=1.7  V=1.7  W=1.7

1011 turns of 22 gauge wire at 1.7V will yield 2000 gauss at 800 ur

Nicely done!  Thanks for the correction. Plus you used SI - easier on the brain.
And one of the reasons I have half a grasp on the math is due to your considerable math skills and patience! 

(P.S. The original question was for 3/4"diameter core so it should be adjusted to 310'  5ohms)

And I've wondered..... how do you the include the core diameter into the flux density calculations (AT)?  It seems you can do this, and that, but not this AND that! lol

[Xaverius]

Nicely done!  Thanks for the correction. Plus you used SI - easier on the brain.
And one of the reasons I have half a grasp on the math is due to your considerable math skills and patience! 

(P.S. The original question was for 3/4"diameter core so it should be adjusted to 310'  5ohms)

And I've wondered..... how do you the include the core diameter into the flux density calculations (AT)?  It seems you can do this, and that, but not this AND that! lol

Actually it is 3/8", not 3/16", my typo.  The adjustment for 3/4"  for the same number of turns would be R=1.7 x 2=3.4ohms, 106 feet x 2=212 feet.  3/4 divided by 2=3/8.

The core diameter does NOT affect FLUX DENSITY.  Flux Density is created by AMPERES, NUMBER OF TURNS, PERMEABILTY, CORE LENGTH only.  The diameter affects the LENGTH of the TURNS, therefore the total length of the coil wire, which affects the wire RESISTANCE, longer wire, more resistance.  The diameter also affects the CROSS SECTIONAL AREA, greater diameter yields greater area.  The larger the area for a given flux density then the greater the amount of MAGNETIC FLUX.  The more magnetic flux then the greater the MAGNETIC FORCE.  DOUBLE the AREA, you will DOUBLE the MAGNETIC FORCE.

F=B^2 x A/2u0   u0=4 x pi x 10^-7

2u0=.000002513


EX:   B=.5    A=.01

.5^2  x  .01=.0025  .0025/.000002513=1000N/226 pounds

        B=1      A=.01

1^2  x  .01=.01       .01/.000002513=3980N/905 pounds



EX:   B=1   A=.02


1^2  x .02=.02   .02/.000002513=7960N/1808 pounds

   
         B=1   A=.04

1^2  x  .04=.04   .04/.000002513=15917N/3617 pounds

[Xaverius]

Yes.
1006, 1018, Grade 2 hex bolt, Grade 5 hex bolt

All seemed similiar with my limited tests.
I have recently read several places that without a proper annealing, you might see a 3% increase between the 1006 and the 1018.....
I put out 3 RFQ's for annealing, haven't heard back...... hard to find a resource (like everything else  ) that deals in small quantities.

Have you considered 1010?  I noticed on your reply #71 of this thread, your chart shows 1010 that is NOT ANNEALED has a ur of 1000.  I'm considering trying this.

[capthook]

The 1010 in that chart was hot formed .25" plate.  Hot formed bar may be close.  Any further processing of the material will significantly reduce its permeability.  Cold roll it - reduced.  Cut it to length - reduced.
(look at it sideways - reduced.  lol j/k)
In theory the 1006 is .06 carbon and the 1010 is .10 carbon, so the 1006 should outperform the 1010.
But as I (now) see it, whatever material used will require a proper annealing to achieve the benifit of material chemisty.  Otherwise, the chemisty of the steel is basically insignificant.
And after all, most steel is produced for its structural/workability qualities, not its magnetic properties, unless you get something like the  Carpenter or CMI materials.
However, I would suppose that that the difference might be more apparant between non-annealed materials of different classes.  ie: steel vs. nickel alloy or cobolt alloy.
But even then, annealing is the difference between it being a Yugo or a Porche.

Buch la Fonte(?) made a comment somewhere on this website along the lines of:
Many good ideas that may well have worked have failed due to the use of inferior core materials.  To acheive results requires proper funding and the use of premimum materials properly prepared.

[Xaverius]

The 1010 in that chart was hot formed .25" plate.  Hot formed bar may be close.  Any further processing of the material will significantly reduce its permeability.  Cold roll it - reduced.  Cut it to length - reduced.
(look at it sideways - reduced.  lol j/k)
In theory the 1006 is .06 carbon and the 1010 is .10 carbon, so the 1006 should outperform the 1010.
But as I (now) see it, whatever material used will require a proper annealing to achieve the benifit of material chemisty.  Otherwise, the chemisty of the steel is basically insignificant.
And after all, most steel is produced for its structural/workability qualities, not its magnetic properties, unless you get something like the  Carpenter or CMI materials.
However, I would suppose that that the difference might be more apparant between non-annealed materials of different classes.  ie: steel vs. nickel alloy or cobolt alloy.
But even then, annealing is the difference between it being a Yugo or a Porche.

Buch la Fonte(?) made a comment somewhere on this website along the lines of:
Many good ideas that may well have worked have failed due to the use of inferior core materials.  To acheive results requires proper funding and the use of premimum materials properly prepared.

So you think the 1010 non annealed is not worth it?