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Help Building Electromagnetic Device. Some challenging problems.

Help Building Electromagnetic Device. Some challenging problems.

Help Building Electromagnetic Device. Some challenging problems.

Good day and thanks for looking at my post. :)

I will get down to the business at hand.
I am at the drawing board trying to design a compact device that will produce a powerful electromagnetic field for a short period of time, say 5 seconds or so. My intention is to create a device that can produce a saturation effect in a ribbon of metal.
My understanding is that my device will be limited by the following design features:
1. the wound core. (material)
2. the winding itself and its number of turns.
3. the power supply.
4. the way in which the power flows thru the winding.
5. 9v-18v 6000mah

I have so many questions but for now i will only ask a few.
a. in making the turns around the core i intended on using very small gauge wire with the insulation still on it so that as i form the turns it does not short across "loops" effectively lessening the number of turns. will this disturb or inhibit the transfer of energy to the core in an appreciable way? thoughts?
b. instead of connecting the device straight to a battery i intend on using an arduino board to control external switches, these switches are intended to control a seperate circuit (the EMC circuit) I am wondering if a can 1. use capacitors to discharge large voltages thru the winding or 2. create something similar to the HEI ignition system (ie. using the high backfed voltages of low voltage circuits being opened and closed. option one seems more likely to work.
and finally
C. what is the ideal core to use in this inexpensive project? a simple iron bar or bolt?

RE: Help Building Electromagnetic Device. Some challenging problems.

You say in a ribbon? Can you build a "C" shaped core?
If you have a full return path you can get much higher field strength.
And if you can make the "C" tall you can put the windings on the back leg or all along it, whatever is easier.
The smaller the air gap the better.

A pulsed coil will be a lot less than 5sec. more like 0.5sec.
If you want to pulse you will need to fully pot the windings so that they can't move.
Ramping the current will be easier on the windings. (I have seen pulse coil leads made from welding wire grow as windings repel each other)
Actually potting is a good idea anyway, it will minimize fatigue of the windings and help with heat dissipation.
Use an epoxy that is filled for good thermal conductivity.

When you wind you will get NxA, the number of turns times the current, that is what produces the field.
You can use a few turns and high current, or more turns and low current. But with finer wire you will have less packing density.
What is the smallest wire that you can buy that is square? That would maximize the packing.
Pick a wire size, figure out how many turns will fit in your space, choose a max current, see what the NxA is.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

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