Re: Welders vs. Variac ballasts, was Rotaty popping, (Was Re: comm
In a message dated 4/29/00 7:05:21 PM Pacific Daylight Time, tesla-at-pupman-dot-com
<< Hi Ed,
OK, so the welder was infinitely variable, and had a wide inductance
range. Did you ever use the welder with the .05uF cap, or only with
the .025uF set up? I'm thinking maybe that made the difference....
the cap size? I'm still having trouble seeing what the difference would
be between a welder and a variac if they both have the same inductance
(other than saturation issues that is). Maybe the welder inductance
did not go low enough? I'm wondering if the improvement you're seeing
is due to the larger caps, not due to the use of the variac. Although it
is possible that when you added the larger caps, you no longer had
enough inductance range in the welder. A different sized cap, requires
a different amount of inductance. Also, for a given total power and
spark length, a larger cap will not need to charge up to as high a
voltage assuming the break rate is still the same, so this in itself
would keep the cap voltage lower, etc.
I think the variac has a lot of inductance for its size because the
toroidal core shape really does a good job of containing the
I did run the coil with the original .025 ufd cap and the new variac ballast.
I stayed with the same cap until I solved the 60 hz primary resonance
problem. Once I got the problems resolved and the coil running smoothly,
then I added the second cap in parallel. The problems using the welder
remain a mystery to me.