Magnetic field power levels

Endersworld · Post by **Endersworld** » Mon Mar 05, 2012 2:40 am

Whats the best ratio of voltage and amperage to use for powering the coils, using size 10 solid core?
Intending on producing a field that has an exterior magnetic field of 1/2 inch diameter around the wire.

ladajo · Post by **ladajo** » Mon Mar 05, 2012 6:41 pm

What field level are you going for?
This will determine turn count and volts/amps. (You will also need to know intended diameter, so you can get total wire length.

kcdodd · Post by **kcdodd** » Tue Mar 06, 2012 1:33 am

So power is P=I^2*R, R is about R=c*N*Pi*D/a, D=coil diameter, a=wire area, c=some material constant. But, a=A/N, A=coil cross-sectional area. And B-field goes as B=u*N*I/D, u=mag. constant. So, P=c*Pi*B^2*D^3/(u^2*A). Which does not depend on the number of turns. So it doesn't matter what you use as long as you have a thick coil (big A).

Endersworld · Post by **Endersworld** » Tue Mar 06, 2012 1:49 am

10" long wire, 1/4" spacing, 6 turns plus 2 inches for attaching power supply.

is there a way to transfer less heat to the coil, and more to the field around it? Does AC power heat the coil as much as equivalent power DC?

I want to heat a Thoriated tungsten rod with it.

kcdodd · Post by **kcdodd** » Tue Mar 06, 2012 2:28 am

so youre making an induction furnace?

Endersworld · Post by **Endersworld** » Tue Mar 06, 2012 3:32 am

Basically yes, I'm hoping that the Thoriated tungsten can be super heated and emit massive infrared radiation, without melting. I can then use the heat coming off of that to heat the atmosphere to plasma around it. I may also put this into a chamber to be shot with microwaves to promote plasma formation.

Microwaves hitting the red hot tungsten should have similar results as a flame in a microwave, but more contained around the tungsten core.

I either need to make the coil outside of the plasma generation area, or use a fluid or air cooling for the coils, the tungsten should be contained in a ceramic or glass tube that microwaves can penetrate and heat cannot, with a constant air flow through it.

like this but with atmosphere instead of argon, and with tungsten in the center.

kcdodd · Post by **kcdodd** » Tue Mar 06, 2012 4:35 am

ok. well, what you need is a monster transformer with heavy duty windings. to step down I wall voltage to the large currents you need. Alternatively you could get some monster igbt's and make a switching power supply run off some batteries. I think typically these things operate at a few kilohertz if you go that rout. but you should do some research on it. will be some intricies depending how you go about it but it probably will run some money to do what you want. And will be some safety concern too. The coil is the easy part. power supply is the hard part.

However, i don't know if hot tungsten will make a plasma. If you have the dough you may see about a standard 13.6Mhz supply, which is typically used to generate the plasma directly without any intermediates. You don't need as much power since its not heating up as much material but still it requires some know-how.

Endersworld · Post by **Endersworld** » Tue Mar 06, 2012 5:05 am

I have a small (800 watt) and large (1200) microwave transformer, a 2/35/200 amp 12 volt DC power supply, and a 90 amps worth of deep cycle batteries. Also potentially a large car alternator I could run off a gas engine.