# Re: [TCML] Short Circuit.

```Great answer! So the inductance must be at a minimum of 21mHy. Besides a sophisticated cooling system, what can be done to keep it from running so HOT! It seems that more impedence is the only option. I can't change the voltage or the amperage so I guess this means more windings or other in-line resistance. You have answered my question...Thank you very much.

Chip

---- mddeming@xxxxxxx wrote:

Hi Chip,
Your question is anything but trivial!

Here's some of the math:

for an AC circuit, Z=E/I
Z=impedence in Ohms
E= voltage
I = current in Amps

In this case, E=120V and I= 15A, so Z= 120/15= 8 Ohms.
If we assume that the capacitance of the coil is negligble,
then Z=XL, and XL=2pifL, where f is the frequency in Hz and
L is the inductance in Henries
so we have 8=377L, or L= 21mHy.

Not knowing the exact characteristics of your type of pipe, etc, it would be easier to
use an inductance meter and wind to the proper value.  At 60 Hz, Ldc is very close to Lac.
Note::This is the minimum inductance that will keep the breaker from popping,
however, it will get very hot, very fast as W=I*I*Z=1800 watts will be dissipated in the coil.
It will require some sophisticated cooling to keep it from becoming slag in short order.
Hope this helps a little.

Matt D.

-----Original Message-----
From: chipford <chipford@xxxxxxxxxxxxxx>
To: tesla <tesla@xxxxxxxxxx>
Sent: Mon, Dec 26, 2011 8:10 am
Subject: [TCML] Short Circuit.

Hopefully the Moderator will let this pass.
I was thinking of building a solenoid type device to trigger my coil. I know
here are other ways but, it brought to mind a question to me. First, if I take
6" pc. of wire and stick it into any common household 120 volt outlet, it will
ause a short circuit and kick my 15 amp breaker. So, lets say I have a pc. of
ild steel pipe, 1/2" in dia., 12" long with a washer welded to each end
reating a spool. If I have a spool of #12 thhn stranded copper wire, how many
urns will it require to prevent a short circuit and why? I am sure it take at
east a specific value of Henries or Resistance but, Don't know how to do the
ath. What is the math.
120 VAC
5 Amp Breaker
12 THHN Copper Stranded Wire
2" - 1/2" Dia. Mild Steel Tube

______________________________________________
esla mailing list
esla@xxxxxxxxxx
ttp://www.pupman.com/mailman/listinfo/tesla

_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla

_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla
```