Winding a strong electromagnet

[capthook]

X -
The 1215 steel (.09%C) is going to have a lower carbon content than the 1018 (.18%C) and thus a higher permeability.  McMaster-Carr has it in diameters up to 4".  The 1215 is comparable to 1010.

"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."

(?)  How do you conclude 2.9ohms?

[Kator01]

Hi capthook
As I recall your quote here :

As to application - I'm pulsing the EM in repulsion against a PM over a small airgap.

Are you working on a Adams-Motor-design ?

If so have you ever had a closer look at what Thane Heins is doing ?
http://www.overunity.com/index.php?topic=4047.3600

There is an important paper of an engineer by name of Dixon on eddy-current in different coil-design.

http://focus.ti.com/lit/ml/slup197/slup197.pdf

The subject of Peripiteia a a delayed Lenz-action on a prime-mover so the p-m is accellerated unter load.
A must-read.

Regards

Kator01

[Xaverius]

X -
The 1215 steel (.09%C) is going to have a lower carbon content than the 1018 (.18%C) and thus a higher permeability.  McMaster-Carr has it in diameters up to 4".  The 1215 is comparable to 1010.

"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."

(?)  How do you conclude 2.9ohms?

Thanx for the data on 1215, I'll look into it further.

The formula for parallel circuit resistance is 1 divided by 1/r1+1/r2.  The resistance that you gave is 5.87ohms therefore 1 divided by 1/5.87+1/5.87=2.93 ohms..................

[capthook]

AT/m: Your winding is 1.5 inches.  1.5/39(inches per meter)=.0384 meters.  If you have 360AT/1.5inches(.0384m) then H(magnetic field strength)=9375 AT/m.

Line 1 of the chart: converting 298AT to gauss:  given the length of the windings, 1.5 inches(.0384m) then H=298/.0384=7760 AT/m.  u @ 50=.00006282 for a hardware bolt, u @ 2000=.0025 for electrical steel, 7760 X .00006282=.487 Tesla/4875 gauss for  hardware bolt, 7760 X .0025=19.4 Tesla/194,000 gauss for electrical steel.  Of course electrical steel saturates at 1-1.5 Tesla so you would never reach that amount.

Ok - think I know where things are screwed up?

Look at the B/H curves - the H is listed as Oersted or A/m (amperes/meter).  A/m is easier on my brain.
(1 oersted = 79.577 ampere/meter btw)
HOWEVER - the calculations you gave earlier are using AT/m (ampturns/meter).
So one would need to use the AMPS in the circuit rather than the AT.
So NOT the 298 AT but the .48 amps in the circuit?
(1.12V x .48A  = .54W)

So the above SHOULD be:
H= .48/.0384 = 12.5 A/m
12.5 x .0025 = 0.03125 Tesla or 312.5 Gauss (for 2000u electrical steel)

This looks more like it as the tiny input shouldn't be able to generate the large Tesla of the earlier calculations.

(can anyone validate the above calculations please!)

- - -
Thanks for the clarification on the resistance - sorry to make you state it again as you had given that equation before (but this time used 5.87x5.87/5.87+5.87=2.9 ohms ?algebra?). 
It's just hard for me to make "real-world sense" of it.  It's like saying split 1 gallon of gas that weights 2lbs into 2 separate gas tanks and now the gas weighs .25 lbs!

You have renewed my interest in pursing this approach!!    (+200% !!)
- - -

Kator - yes, working on an Adams motor type project.  Thanks for the links.

[Kator01]

Hey Capthook,

it is of  importance to understand this Dixon-Paper. Here it is explained how eddy-currents build up in High-Voltage-Coil ( these hV-Coils are used in Thanes coil-setup in combination with high-current-coils the ones you have in mind ) because Thane is demontrating in many videos that it is possible by combining the two coil-types to cause a delay in the Kick-Back-Force ( drag ) while the high-current-coil is under load.
This leads to a phase-shift of the magnetic kick-back-force right at the moment the driver-magnet is retreating from the coil-setup thus giving it an additional kick ( in the ass so to say ). Just watch the videos an ask him. He is very helpful but also excentic in his answers at times.

If you ever decide to change your concept and adapt your coil-design to Peripiteia-Standard I am almost sure you will end up with an new self-accellerating Adams-Motor.


Regards

Kator01