Winding a strong electromagnet

[Kator01]

Hey capthook,

this google-book link returns a message that this link does not exist.

Regards

Kator

[capthook]

It appears the ultimate core material could be metglass?

http://www.metglas.com/products/page5_1_2_4.htm

Maximum DC Permeability (µ):
As Cast: 45,000
Annealed (High Freq.): 600,000

Saturation Induction (Tesla)   
As Cast: 1.56

Supposedly very expensive.....

"The material with the highest magnetic permeability is Metglas Magnetic Alloy 2714A (Cobalt-based) [7] with a high frequency annealed permeability of 1,000,000 (Maximum DC Permeability (µ)). "

I guess you would have to laminate numerous thin sheets together to make a larger core (or find a company that does that?!?)

This seems beyond my scope at this point.....

Sourcing ANY of the 'fancy' materials is expensive and difficult.  Also - getting them in an easily-usable form seems non-existant (as in solid rod form).
I'm of the notion that an EM core does NOT need to be laminated - and that a solid core would actually produce the best results.

Grain orientated silicon steel (electrical steel) seems a more practical option/the next-best option.

Looking forward to recieving ferrite rods next week for testing.....

Any other ideas/sourcing for other high permeability, practical core material?
Something like a .5" x 3" grain oriented silicon steel rod?

Also - going to the University next week for some research/reading materials.....
- - -

I think the best material is silicon electrical steel which is very common but manufacturers will only sell to buyers with LARGE orders.  If you can salvage the cores from used transformers or inductors you could obtain the material, but I'm not sure how to do this.

Me either!  But I would like to find out!

You might try ScientificAlloys.net.  They have a variety of materials and their sales personnel can provide information. 

I will call them Monday.

[Xaverius]

I know this might step off topic, but I've got to ask...

Say you are to make an electromagnet where you use a great number of single turn conductors wired in parallel.  Does this create an EM with nearly zero resistance, reactance, and impedance?  What kind of capacitance would such a device have compared to one of an equal number of turns wound from only one continuous conductor?

M.

The more single turn conductors wired in parallel, the closer to zero the resistance, reactance, impedance.  The capacitance would be the same with an equal number of turns from the same conductor.  You can use the Medhurst formula.

[Xaverius]

It appears the ultimate core material could be metglass?

http://www.metglas.com/products/page5_1_2_4.htm

Maximum DC Permeability (µ):
As Cast: 45,000
Annealed (High Freq.): 600,000

Saturation Induction (Tesla)   
As Cast: 1.56

Supposedly very expensive.....

"The material with the highest magnetic permeability is Metglas Magnetic Alloy 2714A (Cobalt-based) [7] with a high frequency annealed permeability of 1,000,000 (Maximum DC Permeability (µ)). "

I guess you would have to laminate numerous thin sheets together to make a larger core (or find a company that does that?!?)

This seems beyond my scope at this point.....

Sourcing ANY of the 'fancy' materials is expensive and difficult.  Also - getting them in an easily-usable form seems non-existant (as in solid rod form).
I'm of the notion that an EM core does NOT need to be laminated - and that a solid core would actually produce the best results.

Grain orientated silicon steel (electrical steel) seems a more practical option/the next-best option.

Looking forward to recieving ferrite rods next week for testing.....

Any other ideas/sourcing for other high permeability, practical core material?
Something like a .5" x 3" grain oriented silicon steel rod?

Also - going to the University next week for some research/reading materials.....
- - -
Me either!  But I would like to find out!

I will call them Monday.

Some of the more exotic materials such as Metglas, SuperMalloy, etc have extremely high permeablities but relatively low saturation points(.25-.5 Tesla). Metglas can be purchased as a spool of ribbon but I priced it on Ebay for $125.00 for 50 feet.  It is also very sharp so it's difficult to handle.  I tried thin strips of GIron which is similar material and it didn't perform at all, I think these materials are only magnetized along the plane of the material(normally used for magnetic shielding) so I don't have a lot of confidence in using them. 

If you have access to a Sabre Saw with a metal cutting blade you might be able to obtain electrical steel laminations from salvaged objects.  You'll need it to cut the core material into the desired lengths/shapes.  I've heard old washing machine motors have cores that are easily used.  Might be worth trying.

If you don't use laminated steel or ferrite, the Reactance will be much greater.  If this is not a factor in your design then no problem, but if amperage optimization is important then you must consider using them.

[Kator01]

Hello All,

here a good website from australia :

http://www.magneticsolutions.com.au/

@capthook: Some Killerrobot is obviously observing certain activities. I was accessing the patent-link

http://www.pat2pdf.org/patents/pat3670189.pdf

and downloaded the Pdf-File. A minute later accessing the same link again ( I had closed the window after download ) an error-message popped up saying that the file has been removed.

Regards

Kator