Re: General Questions VIII

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

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

Hi Wade,

At 10:27 PM 6/7/2001 -0500, you wrote:
>Hi Guys,
>
>I'm a little disappointed in the response that I received about how long
>will the TC operate???

When things are busy like this week.  Stuff sometimes goets "lost"...
Thanks for asking again...

>
>I've spoke with a couple of different people here in Omaha, and they seem
>very confident that TC's operating with static or rotary gaps can run for
>very short periods of time. Where a solid state driver is more reliable.
>I'm hoping that you folks will clear this up for me???? Please.

I almost first must ask... how long do you need your coil to run
continuously or before you have to fiddle with maintenance?

Spark gaps are the biggest wear point.

Static gaps need the most "work" since the surfaces are fixed and foul
pretty fast.  I would guess that 15 to 30 minutes of operation is a good
time to clean them but tungsten and such could go a lot longer, like hours...

Rotary gaps are used in museums and other "low maintenance" coils.  A good
tungsten rotary gaps (like Bill Wysock makes) can probably go hundreds of
hours before you need any serious intervention.

Toob coils can probably run for hundreds to thousands of hours if they are
made with care can maybe a fan.

A truly solid state coil...  Mine uses an RF generator rated at 31 years
Mean Time Between Failure...  The electrode will probably burn off before
that.  Maybe in a year, or two, or five...

The cost goes up as one goes down this list.  The high voltage will degrade
the plastics and such too...  You can probably really design one to last as
long as you wish.

>
>Onto a good question.....Will matching the impedance's of the primary and
>secondary coils increase effeciency and performance of a TC??? Or is it
>even necassary.

The primary should definitely be matched to the charging circuit's
impedance.  The secondary works best if it is tuned to the streamer
impedance.  The standard NST and primary capacitor matching stuff will
handle the primary.  A good assumption is that a streamer load is 220K ohms
plus 1pF per foot of streamer length.  This gets really messy when the
non-linear spark gap is added in since it all then needs computer modeling
to handle the non-linearities and non-continuous time functions...
MicroSim models are pretty popular at this level:

http://hot-streamer-dot-com/TeslaCoils/Programs/Programs.htm

See the bottom of this page for the MicroSim free version download and
models of my coils.

Hope this starts to answer your great questions...

Cheers,

	Terry

>
>Anyway, Thanks
>
>Wade
>