RE: Help!!!, Building my first Coil Recommendations

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

Original poster: "Lau, Gary by way of Terry Fritz <twftesla-at-uswest-dot-net>" <Gary.Lau-at-compaq-dot-com>

Comments interspersed:

>Original poster: "raven0075 by way of Terry Fritz <twftesla-at-uswest-dot-net>"
><raven0075-at-home-dot-com>

>I have picked up my NST 12KV 30 ma
>I am planning  to build a small coil 2' feet tall + Toroid. 
> 
>1. what safety chokes size do I need and where to order them from.

While it was once widely thought to be the right thing, the use of chokes in
protection networks is no longer recommended.  Instead you should use an R-C
network.  R of 1-2K/50W, bypass caps of ~500pF.  See circuit diagrams on my
web site at:
http://people.ne.mediaone-dot-net/lau/tesla/protection.htm

>2. Now I need to know what size Commercial caps should I use, or if I go
MMC
>what size do I need. and how many? and do I need to put a resister across
each one.

The exact capacitor value is not too critical, as long as it's in the
ballpark, and of course, that the pri/sec tuning is correct.  Something in
the order of .005-.01 uF.  You can make a cheap MMC with as few as ten
.056uF/1600V polypropylene caps in series.  Use of bleeder resistors is
cheap and a good idea.

>3. How fare apart to I leave my spark gap?

Ideally you should set the gap such that with no cap in the circuit, the gap
just barely fires.  I would guess something like 0.25".

>4. what size copper tube should I use for my Primary coil and how many
turns.

The primary coil tubing diameter won't have any bearing on electrical
performance, it's just a matter of mechanical concerns - how easy it is to
tap.  0.25" tubing is typically used.  I'll leave it to you to figure out
the number of turns, but you should plan on having at least 10-15 turns.

>5. What size PVC should I get and how tall should I go, recommendations
>please

For a 12/30 NST powered coil, I don't think you'd see any benefit to going
above 4" diameter x 23" long (winding length) secondary.
.
>6. What awg magnet wire should I get, and how many raps on the secondary
and
>how is it fastened to the PVC.

Between #22 and #28 sounds good, fit as many turns as will fit in 23".  Do
not drill a hole in the pipe to secure the wire ends.  Glue the ends in to
secure them, then coat the entire coil with brush or spray-on polyurethane.
I would recommend building a winding jig with a hand drill to assist with
the winding and polyurethaning so it doesn't drip and run.  See:
http://people.ne.mediaone-dot-net/lau/tesla/secondary.htm

>7. How large should I make the toroide?

You can start with something like 4" x 16".
 
>??On connections,  If some one wouldn't mind a phone call, so I can get
some of
>my more in-depth questions answered.  When I first started thinking  about
a
>Telsla Coil I thought oh just a little simple thing slap some wires
together a
>little transformer how hard can it be, What the Heck was I thinking.

You mean the circuit diagram?  This is why people have web sites.
Schematics are difficult to convey over the phone, picture and a thousand
words and all...  See
http://people.ne.mediaone-dot-net/lau/tesla/myschematic.gif

>I am just getting into this and I have been reading on this for about 3
weeks,
>I am still working all the math and terminology, kinda overwhelming at
first.
> 
>Thanks all the help I can get will be appreciated.

The recommendations I've made above are just a starting place.  I've made no
attempt to calculate whether pri-sec tune will be achieved.  This is where
you have to do some work.  I don't know what size cap, secondary wire, and
toroid you will ultimately use, so YOU need to ensure that it all comes into
tune.  There are several excellent computer programs to help with this.  I
recommend that you download:

Wintesla.exe at http://hot-streamer-dot-com/TeslaCoils/Misc/.  This program will
calculate the inductance of your primary and secondary coils based on what
dimensions and wire size you use and will calculate the resonant
frequencies.  Unfortunately it does a poor job at calculating the toroid's
capacitance, so you should use:

ETelsa6 at http://hot-streamer-dot-com/TeslaCoils/Programs/Programs.htm.  This
program is the ONLY way to calculate the resonant frequency of your
secondary/toroid combination.
 
Regards, Gary Lau
Waltham, MA USA