Winding a strong electromagnet

[Xaverius]

@ CapNhook,

      please let me know how your salvage operation goes, that is where you find junk and how you dissect the metal.

Another avenue is motor/generator components.  I contacted a local motor rebuilder.  He had no parts in stock.  He said to contact the manufacturer directly, that's what he does.  It is possible to obtain pole pieces, they are used for salient rotors and stators.  I did a search from several manufacturers including GE.  Their site is so damn big it's like looking for a needle in a haystack.  Any parts you find should list a data sheet with dimensions, core material, heat resistance, etc.  So far I haven't found anything, but I'll keep looking, it seems the manufacturers don't list their product components.........

[capthook]

Attached are useful (and hard to find) material B/H curve comparisons and some annealing data.........

[capthook]

Xaverius-
I have ordered some 1006 steel and am proceeding that route for now.
I'm thinking that is going to improve performance significantly over a hex bolt and is the best material when considering ease of sourcing and cost.
(An upgrade to 99.99% iron fully annealed to 1700 deg. F in hydrogen atmosphere would be my next choice: $$$ )

Ways to source scrap laminated electrical steel:

Old microwave: http://www.overunity.com/index.php?topic=4047.msg101636#msg101636
(step by step pictorial)

"You can also get good laminations from junked alternators." wattsup

- - - -

And I've been doing some thinking on your "2-in-hand" winding of an EM to reduce resistance and thereby increase amps and AT.  But......

(if) The goal is the most AT/watt.

Ex:

3/8" x 3" core
#24 AWG
Windings 1"OD x 1 7/8" L
10mm ID x 26mm OD x 48mm L

# turns: 1232   
Ohms: 5.87   
volts: 1.5
amps: 0.256   
watts: 0.383   
AT: 315

Now wind that 2-in-hand.  Each coil then equals:
# turns: 616
Ohms: 2.28
volts: 1.5
amps: 0.658
watts: .987
AT: 405

Add the 2 coils together you get:
ohms: 4.56
watts: 1.97
AT: 810

SO - results:

AT increased by 257%
Watts increased by 514%

A large increase in power for a relatively smaller increase in AT

If AT/watt is not the criteria, but instead is maximum AT for a given coil size/dimensions, the 2-in-hand would be the way to go.

However, if AT/watt IS the criteria, then 2-in-hand is less efficient.

Yes?

[Xaverius]

CapnHook, good luck with your 1006.  That seems to be a viable way to go.  I would order some from McMasterCarr, myself, but the largest diameter is .5 inch and I need 1 inch.  I'm looking at 1018 now from MSC, lower ur but 1 inch diameter.

I'll check the microwave scrap link.  I guess I would have to look for some used alternators and microwaves.

Actually two coils wired in parallel would have lower total resistance that  would be less than the lesser resistance of the two.  In your example, wind another coil with the 1232 turns, fasten them in parallel, the total resistance is now 5.87x5.87/5.87+5.87=2.9 ohms.

1.5/2.9=.51 Amperes......   .51x1.5=.76 Watts   1232x2=2464   2464x.51=1256AT

1256AT/.76Watts=1653AT/Watt

When you REDUCE

[Xaverius]

.......(continued).......the TOTAL RESISTANCE, then the AMPERAGE will INCREASE which will INCREASE the TOTAL AMPERE-TURNS.  If the VOLTAGE remains the SAME, then the TOTAL WATTAGE will INCREASE.

I believe in your first application: 315AT/.383 watts=822AT/watt

1653/822=200% gain


Please let me know if this makes sense with your application.