RE: Many questions

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

Original poster: "Mccauley, Daniel H by way of Terry Fritz <twftesla-at-qwest-dot-net>" <daniel.h.mccauley-at-lmco-dot-com>

I m a new coiler and have done a great deal of research to design the coil I
m
currently implementing.  I ll give all the specs and then ask the questions.

(please keep in mind the only part actually built is the primary, the rest
can
possibly be changed by recommendation) The coil transformer is a 15kV 450VA
30mA 60hz output neon light transformer. The capacitor is a 25kV .3uF box
capacitor I bought off ebay.  The primary is 7 diameter 6 gauge copper wire
wound in a helix with 4.17 turns and approx 1.2 space between windings.  The
secondary is 21AWG enameled magnet wire 1395ft wound on a 4.25 diameter pvc
pipe 39 tall.  It is tuned to approximately 177kHz. The top load is a 30
x6.25
toroid.  The spark gap is a collection of 10-½ copper pipes (1.5 in length)
screwed to a piece of plexiglass with around .025 gap between each and a fan
blown over the top.  I got all these calculations by playing with the TC
java
tesla designer. However I m not sure if this is going to work correctly.
The
low amount of turns on the primary seems odd to me (I know if I use the
recommended .066uF capacitor (by another java designer) it says to wind 18
turns).

 

Questions:

 

Do you feel this should work?

>>>>>>>>>There are some problems I see.  First, the capacitor is way too
big.  For that transformer you should be using
a 0.005uF capacitor.  Thats almost two orders of magnitude smaller than what
you are currently using.  Also, for maximum tunability you probably want at
least 13 to 15 turns on the primary.  And the toroid seems much too large
for that transformer size.  You'll get streamer break-out if you attach a
sharp break-out point to the toroid, but i don't think you'll ever get the
toroid to break-out under possibly full-out power.

What wire should I use to connect it all together and what type of
connectors?
I bought high voltage wire but it doesn t handle much current.

>>>>>>You are going to hear many schools of thought on this.  I use 14 AWG,
60kV High voltage wire on mine (currently a 15kV/120mA) coil and it works
just fine.  Other people will say you absolutely need like 8 AWG or 4 AWG
welding wire, but you should be fine with only 12 AWG regular stranded wire.

How and where should I ground it?

>>>>>>>>>Check out the current threads on ground now.  Just go to home
depot, get a ground rod (usually about $6) pound it into the ground and then
get some thick grounding strap to attach the bottom of your secondary to it.

How should I connect the toroid to the top of the coil and should I leave
some
blank pvc before the toroid?

>>>>>>>>>>>>See my web page.  www.spacecatlighting-dot-com

What do you recommend I use to coat the secondary?

>>>>>>>>Again, two schools of thought.  Some prefer orange shellac and some
prefer polyurethane.  I prefer polyurethane.  Buy this at homedepot or any
other hardware store.

If you could change something on this coil, what would you change?

>>>>>Capacitor, primary, and size of toroid.


Hope this helps.


Thanks for all your help,

 

Matthew Morrissette

MIT frat boy Sophomore in Comp Sci and EE looking for fun with a tesla coil