Winding a strong electromagnet

[capthook]

It is "soft" - non-magnetized. As is the ferrite I ordered (guess it will be here Monday).
And when you remove the magnet - it loses it's magnetisim right away - no remenance.

[capthook]

Amp turns per watt:

Some time ago I ran some numbers to try to find the "efficiency" of an EM winding.  How to get the most AT (ampturns) per watt.

I used the awesome coil calculator to determine wire length, # turns and ohms at:
http://www.coilgun.info/mark2/inductorsim.htm

The attached picture is of an excel spreadsheet showing these.
I'll run some more in the near future - and post the thing as a .pdf (I hate downloading an unknown .xls)

This is a winding comparison using the same winding length - 1.5" (not wire length) and core.  The actual gauss/tesla would depend on the permeability/width of the core?

Note the appreciable difference between the 1st and 2nd winds.  #2 is MUCH more efficient!

Comments?  Additional math to apply? etc?

[Kator01]

Hy capthook,

tedious work, really. I now would take double the length 740 ft ( not double the AT) of this #2 calculation and make two seperate coils a 370 ft and put these two coils in parrallel. Now you have the same input-wattage and much more Tesla.

I have to think about optimization based on your excel-data.

good work

Rgards

Kator

[hoptoad]

This is a little off topic (sorry), but, if you are not an electromagnet purest, and you don't mind the idea of utilizing permanent magnets to aid the electromagnets in their specific task, then you may try to incorporate one of NASA's early space exploration ideas:

visit this link: http://www.cheniere.org/misc/astroboots.htm

Cheers from Hoptoad.

[Xaverius]

It is "soft" - non-magnetized. As is the ferrite I ordered (guess it will be here Monday).
And when you remove the magnet - it loses it's magnetisim right away - no remenance.

Yeah, the ferrite I have reacts to a permanent magnet positively, that is it is attracted to it, and no remanence.  Very little EM abiltiy however.