Re: calculating safe primary turn-to-turn distance

["Garth van Sittert" <garth-at-mediasupplies.co.za> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

Yes, you are correct.  The AC current sees an AC impedance (similar to DC
resistance) accross the primary coil.  To calculate (approx.) the voltage
per turn on the primary take the primary voltage and divide it by the number
of turns.

My coil:  12000V (RMS) / 8 turns

1500V between turns.

This excludes peak voltage and the extra high voltages created by the
resonance of the primary circuit.  I suppose that peak primary voltages
could exceed 30kV in my primary.  I wouldn't go less than 0.25" spacing.

Garth


----- Original Message -----
From: Tesla list <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Saturday, August 26, 2000 7:43 AM
Subject: calculating safe primary turn-to-turn distance


> Original poster: "Stan" <sdarling-at-columbus.rr-dot-com>
>
> Greetings all,
>
> I have been curious since I started doing Tesla coils about this:  how
> does one calculate the minimum air distance of turn to turn spacing in a
> primary for a given voltage?  I'm not an EE so my common sense tells me
> that current always favors the path of least resistance and that even a
> tiny distance of air would have a much greater R than the adjacent half
> turn of Cu tubing. So if the adjacent turns weren't touching, why would
> it ever arc over through the air?  I suspect it has something to do with
> the inductance of the Cu tubing coil(s) ....
>
> Feeling stupid in Ohio.
>
> -Stan
>
>
>
>