Electro magnet design software advice?

[acp]

It's part of it, the lua scripts are just text files with a ".lua" ending. I'll send you a model with a script if you like. check your private mail in 1/2 an hour or so.

[acp]

Hi Honk I found your email adress, let me know if you got the files and if you were able to run it. If you have questions I will try to help.

Regards

Albert

[dingbat]

Honk,

http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/magcon.html#c1

this is a pretty good site on magnetism in general.  It explains a lot about the relationship between turns, current, core materials, etc.

The formula for flux is basically amps times turns time the permeability of the material. (until you saturate the core)  Units are gauss, I think. (1/10000 tesla)

The length of the coil does come in to play somewhat, but not like the permeability and ampere turns.  The coil weakens as it gets longer.

I think the area of the core will mainly affect the saturation point.  You need enough core area to carry the flux.

For example:
1000 turns
0.05 amps
2000 permeability

flux = 1000 x 0.05 x 2000 = 100,000 gauss, or 10 Tesla

Your core must have a large enough area to carry 10T without saturating.

[Honk]

For example:
1000 turns
0.05 amps
2000 permeability

flux = 1000 x 0.05 x 2000 = 100,000 gauss, or 10 Tesla

Your core must have a large enough area to carry 10T without saturating.

This is how I understand it. The magnetic flux in the core will behave much like pressure (like water in a hose).
In a large diameter hose the pressure is low. When the hose is getting more and more narrow the pressure will
increase until the point that it cracks the hose. The cracking point = The saturation point of the core.

Using a big core with 1000 turns the flux will be lower than using a smaller core with 1000 turns.
But the smaller core will saturate at the same number of turns and current.
This why the coil and the core have to be calculated to never go past 2 tesla.
Trying to get 10 tesla is just waste of energy that will heat the core until damaged.

Your formula above is great but I'd like the area of the core to be included in the equation if possible

Thanks /Honk

[dingbat]

This is how I understand it. The magnetic flux in the core will behave much like pressure (like water in a hose).
In a large diameter hose the pressure is low. When the hose is getting more and more narrow the pressure will
increase until the point that it cracks the hose. The cracking point = The saturation point of the core.

Using a big core with 1000 turns the flux will be lower than using a smaller core with 1000 turns.
But the smaller core will saturate at the same number of turns and current.
This why the coil and the core have to be calculated to never go past 2 tesla.
Trying to get 10 tesla is just waste of energy that will heat the core until damaged.

You are right about the area - I forgot Tesla is flux density, which implies flux lines per square meter.  The ampere turns times the permeability will give flux lines, but not density.

I think your analogy to a hose applies, but don't confuse flux with pressure in the magnetic sense, because the term "magnetomotive force" is given to ampere-turns.  It is defined as the "force" that causes flux.  It is described as being analogous the voltage in electricity.  Voltage is the driving force that cause current where there is a path for the current.  The amper-turns is the driving force that causes flux in a permeable path.  Similar to electricity, the more "conductive" (permeable) the path, the higher the flow of current (flux).

The area of the core is somewhat like the cross sectional area of the wire.  Bigger wire = higher current capacity.  bigger core = more flux capacity (not more flux density, which is flux per area)

mostly just thinking out loud to help myself try to get a better understanding of all this.

db