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RE: First light - sort of


Greets again,

Ron I forgot to report something else I altered on the plans that
helped out.  I put a 100k ohm variable resistor in series with
the 10kohm resistor the plans called for.  So maybe
play with that resistor and see if this helps some.  I found the 
higher frequency gave much better results.  It's also more fun
you have a dial knob to adjust things on the fly.  Put some good
insulator tape on the potentiometer, trust me it will bite a little.

Cheers, 
Bill

> -----Original Message-----
> From: Tesla List [mailto:tesla-at-pupman-dot-com]
> Sent: Saturday, February 19, 2000 2:52 PM
> To: tesla-at-pupman-dot-com
> Subject: First light - sort of
> 
> 
> Original Poster: "Ron West" <ronwes1-at-juno-dot-com> 
> 
> I had somewhat puzzling results with my new coil last night.  The first
> thing I should say is that I am building this coil in two stages:
> 
> First stage, I built it with a VERY low power source (anyone familiar
> with the "Solid State Tesla Coil" plans in the Nov. '99 Popular
> Electronics? - 24 volt transformer stepped up by two auto ignition
> coils).  I did this to learn the priciples and safety involved in
> building a coil and as an introduction into HV before jumping in with
> something larger.  My coil has a primary with 11.5 turns of 1/4" copper
> tubing wound with inside diameter of 7" and outside of 18".  Secondary is
> 4" coil form with 21.2" of 22AWG polyester-amide-imide magnet wire.  Cap
> is two series-connected Glasmike mylar caps totaling 27,500 volts 25nF. 
> Voltage out from the ignition coils is about 12KV but I have no idea what
> the current is.  Torroid is 4" X 12" aluminum ducting.  I went all out on
> my ground, I have 5 - 8' copper clad rods spaced at 8' interconnected
> with 4 AWG bare copper wire and connected to the coils via 2" wide copper
> strap.
> 
> Second stage, to use the coil (primary and secondary coils and the base)
> as a "stepping stone".  I plan to upgrade this to a 'real' coil with NST
> power source, MMC, improved spark gap, etc.
> 
> I had expected to have 6" - 8" streamers (according to the article) but
> only got 4" sparks with some corona visible on a ground wire held near
> the toroid at about 6".  This may be all this coil is capable of (and it
> may already be time to proceed with stage 2), but it brings up a few
> questions I hope somebody can answer.
> 
> When tuning it seems to tune at (only) 4 turns.  I had expected it to end
> up closer to 8+ turns.  Is this somehow related to the low power, or is
> it simply a result of the frequency of the secondary?  In other words
> when I change to my NST will I need to re-tune to more turns?
> 
> Could the torroid be too large or two small for the coil?  I tried the
> coil without the torroid and the sparks were only about 1" in length
> instead of the 4".  So the torroid does seem to be doing it's job, but
> maybe it could be more efficient?
> 
> Thanks to everyone for a great list,
> Ron West
> 
> 
>
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