Re: Flat secondary measurements

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>

Hi Peter,

At 12:38 PM 2/15/2002 -0800, you wrote:
snip...
>what I meant was that this is a simple geometric change that should require
>only simple changes to the software (not require rewriting EM theory... :-)))
>
>I am imagining two slightly different geometries though
>
>a) upside-down TC - flat secondary has inner diameter about the same as
>   the diameter of the helical primary, and they would be grounded together
>   there (using a single ended OBIT to power the TC). The outer edge of the
>   flat coil will be the high voltage end - place a toroid there.
>   
>b) the primary is helical but at the outer diameter of the flat secondary,
>    so the secondary's inner diameter is quite small, and run a wire upwards
>    perpendicular to the coil to a spherical topload.
>
>The real problem with both of these is that the turn-to-turn voltage will
>be much worse for a given overall size than with a traditional helical
>secondary. My 12" high helical secondaries have 11" between top and bottom,
>but a 12" diameter flat coil will only have ~5" between its inner and outer
>windings. That is twice the volts-per-inch flat verses helical if you're
>trying to get the same voltage from each (that may or may not be relevant
>to spark length, which tends to be more dependant on bang size, but we wont
>know what happens with flats until we try them...).

Changing the code is pretty simple if I know the data and voltage profiles
to use.  E-Tesla can predict voltage stress so arc over points could be
predicted.  "parts" can be arbitrarily placed anywhere but I Just have to
be sure there surface voltages are correct.  Right now, I assume the
primary (the flat one) is a ground.

>
>
> >
> >** Oops!!  The secondary voltage profile will not work...  Hmmm...  A bit
> >of less than trivial change there.  I will look at it when I get a chance,
> >I have to go buy some parts to start building my flat secondary right now
> >   :-)))
>
>
>Paul will have to work out the current/voltage profiles over the radial
>dimension of the flat coil. Again I'm assuming this is a simple geometric
>change from the existing ones and the software will be simple enough to
>change.

Having the voltage profile across a flat secondary is a very key thing!!!

>
>
>>
>>I though at least finding the wire length would be easy, but I see Jim's
>>work is looking pretty complex (Make use of b^x = exp(x*ln(b)) so now you
>>can integrate using integral( exp(ax) ) =1/a*exp(ax), where a=ln(b)...)  It
>>"sounded" easy but...
>
>
>WHAT???
>   wire_length = number_of_turns * PI * (average_diameter, ie (ID+OD)/2)
>DOH!!!
>

I guess they are far beyond the wire length in that thread...  I am not
sure what they are taking about now...  Since they were not tearing each
other's throats out on that thread, I have been paying attention  ;o)))

Cheers,

	Terry