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New cap test run
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From: Charles Brush [SMTP:cfbrush-at-interport-dot-net]
Sent: Saturday, June 13, 1998 7:20 PM
To: Tesla List
Subject: Re: New cap test run
> Glad to hear that your coil is cranking out those big sparks again! As
> you and I discussed last year, we have pretty similar systems. Last Fall
> With a 6" form wound to 28" (#22 double formvar) I was up to 77". Not up
> to the max you've achieved, but I'm still trying! :-) That coil has been
> in storage for the last seven months, so I'll have to see how it performs
> this summer with some tweaking.
>
> Zap!
>
>
> Charles Brush >>
>
>
>
>Charles,
>
>Sounds like we have about the same performance. How much power were you
>inputting for 77" sparks? What are you using for an inductive ballast? Do
>you also use series resistance?
>
>Ed Sonderman
Ed,
Well my best estimate would be somewhere between 3.5kW and 5kW. The
ammeter usually stays around 13-20 amps, yet the coil can occasionally trip
a 35amp breaker when the ammeter is reading 20 amps or so (it's pulling
current in pulses after all, so it's hard to tell where the peaks are).
For current limiting I use a Miller 225amp welder with no added resistance.
This is a very basic setup consisting of a 28amp variac, welder, and two
sets of 200amp line filters on each leg. I used to pop the breaker all the
time before I switched to a rotary gap, but now current draw is much more
even. I was thinking of trying some resistance this summer to see if that
helped to further smooth things out. This coil has also been rewound with
a double layer of #22 as an experiment, but I've noticed no difference in
performance. Spark length was about the same when it was single wound.
Charles Brush
http://www.foundrygroup-dot-com/cbrush/fun
p.s. Ah what a great way to spend a rainy afternoon here in NYC...working
on a new small 6" coil in my apartment!