Re: Power Rating of a coil

In a message dated 99-01-27 21:19:24 EST, you write:

> I just have a quick question about the power rating of a tesla coil. I see
> everyone rates thier coil in watts instead of VA. I was just wondering if
> is done because in a tesla coil the reactance of the primary winding should
> equal the reactance of the capacitor therefore cancel each other out.  So
> to this all that is left is real power? Or am I totally of base here?
> Thanks
> Jess Britt >>


People use VA because they often don't have a wattmeter, and they
also often don't know the TC's power factor.  Other times the "VA" 
figure they mention is actually simply the rating of the NST. 
However, they may actually be drawing much more than the NST's
rated power due to resonant charging and/or poor power factor.
(As an example, my 12kV, 30ma NST, which is rated at 360
watts, actually draws 720 watts in my TC.)

Ordinary ammeters and wattmeters may read somewhat incorrectly
in TC circuits.  Depending on the TC, the meters might read reasonably
accurately, or not.

John Freau