RE: Spark Length was Re: Voltage determination

["John H. Couture" <couturejh-at-worldnet.att-dot-net> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

Bart -

I am talking about the JHCTES Ver 3.1 program. If you change only the
secondary turns input the spark length will increase. The computer makes all
of the other changes necessary to keep the system in tune. You do not have
to make any other changes in the inputs to increase the output spark length.
I agree that more than Ls changes in the system.

Note that all of the variables in the posted equation are factors and not
the usual parameter values.


John Couture

-------------------------
-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Wednesday, July 26, 2000 11:37 AM
To: tesla-at-pupman-dot-com
Subject: Spark Length was Re: Voltage determination


Original poster: "Barton B. Anderson" <tesla123-at-pacbell-dot-net>

Hi Malcom, John C., David,
<a few bandwidth snips>

Tesla list wrote:
>
> Original poster: "Malcolm Watts" <M.J.Watts-at-massey.ac.nz>
>
> In order to increase Ls you *have* to change something else if
> tune is to be maintained, whether it is decreasing Cs
> (physically smaller coil, hence smaller wire, hence higher
> secondary losses), increasing Cp (in which case you'd have to
> lower Vp in order to retain an identical Ep = same Vout) or
> increasing Lp (in which case the impedance ratio is the same =
> same Vout). I think it is unrealistic to simply attribute
> increased sparklength to a change in one variable only when in
> reality others change or must be changed as well. The
> foregoing arguments assume negligible losses in the primary
> which isn't true either and then of course any modification to
> either coil affects k. Not so simple I would say.
>
> Regards,
> malcolm
>

Now this I agree with. It's not as simple as changing Ls, but the equation
posted would suggest otherwise (Spark length = W*Vp*Ls*B).

John, are you saying Ls alone will increase spark length? I'm guessing your
not
meaning to and maybe "only" in a case where Ls was originally not optimal
for
the coil to begin with. But even then, there must be a point where further
increase of Ls moves away from optimal (regardless of everything else that
changes), which suggest that Ls in the equation can't be used in the
mathematical way expressed.

BTW, optimal Ls (IMHO) is governed by the primary tank design. In other
words,
I might be so brave as to suggest that part of the reason H/D becomes a
factor
is biased towards a high loss or low loss primary tank circuit.

Take care,

Bart