3/4" vs. 1" primary on 30 Kw system ?
From: Bert Hickman [SMTP:bert.hickman-at-aquila-dot-com]
Sent: Saturday, June 27, 1998 1:00 AM
To: Tesla List
Subject: Re: 3/4" vs. 1" primary on 30 Kw system ?
Tesla List wrote:
> From: Daryl P. Dacko [SMTP:mycrump-at-cris-dot-com]
> Sent: Thursday, June 25, 1998 7:01 PM
> To: Tesla List
> Subject: 3/4" vs. 1" primary on 30 Kw system ?
> A friend asked me to post this:
> He's designing a coil that might have up to 30 Kw input on the primary (!).
> Would there be a practical differance in performance in going from 3/4"
> to 1" copper tube ?
> The price is about double for the 1", which is why he's asking.
> C = Pi * Dia, so I'd say that resistance would go down by 25%...
> Given the losses in a standard sparkgap, I'd guess that you wouldn't
> see too much differance.
> What does the collective wisdom say about this ?
I'd agree with your assessment. Once the sparks start flyin', I suspect
you'd be hard pressed to tell any performance difference. To some extent
it also depends upon Fo and the tank cap he's planning to run with. For
example, if he's using relatively few (say 3-6) primary turns, he'd be
better off with 1" tubing, since his Ip will be significantly higher,
and the primary's skin-effect resistance may become a significant
contributor to primary losses. If he uses lower tank capacitance and
more primary turns (say 10-15) to get the same Fo, then either 3/4" or
1" should work fine.
-- Bert --