Re: Primary construction

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

Original poster: The MCP <ejkeever-at-comcast-dot-net> 

Well, the wire I'm using is an interesting story... I got 8 rolls of #32 gauge
from mpja-dot-com to be used to wind a *load* of small electromagnets in an
attempt to build a maglev. I ended up using, um... 2 of them. So I've got
about 3 miles of wire, and I wanted to build a tesla coil! And I've *still*
got almost all the wire I started with...

Having this huge amount of wire available was one of the things that made me
consider making little "play-thing" size tesla coils.

On Friday 19 September 2003 06:47 am, Tesla list wrote:
 > Original poster: Bart Anderson <classi6-at-classictesla-dot-com>
 >
 > Hi MCP,
 >
 > 2 turns sounds about right with a slight topload (maybe a point or your
 > coiled wire?). Could you do us a favor and give more info as to the wire
 > type used for the primary? We are still not clear on what your actually
 > using. The topload would also be much needed data. This type of data seems
 > to be very limited from coilers (full specs with center heights).
 >
 > Both John C. and I truly enjoy crosschecking against the programs. We love
 > doing it or we wouldn't. Your coil is pretty cool to run through the phases
 > because of the extreme h/d ratio and small size. The 196 ft of wire is
 > correct (the 394 may have been due to the JHCTES v3.4 radius limitation of
 > 0.5" as John explained). I personally won't recommend the toroid size
 > unless I know your supply specs. With more top C will mean more primary
 > turns. 1.2 MHz would indicate a linear current distribution (which would be
 > wrong).
 >
 > Fres will be higher, but only "you" can prove that with a measurement (John
 > C. and myself always push for measurements when possible). If you don't
 > have the equipment to measure then I certainly understand.
 >
 > As far as calculating the small coil of wire your using as a topload, you
 > might be hard pressed because it's difficult to model this as a topload
 > when it is in situation with other components, except modeling something
 > similar in shape, maybe a sphere. For example, I tried a sphere with
 > dimensions of 2" x 2" at a center height of 12" (above coil). Fres dropped
 > to 2.2 MHz and autotuned at 2.3 turns. Again, I have no idea of the topload
 > used, but this might be a method to try. FANTC may be another option as one
 > can be innovative in it's use. I may try that tomorrow if I get a chance.
 >
 > Take care,
 > Bart
 >
 > Tesla list wrote:
 > >Original poster: The MCP <ejkeever-at-comcast-dot-net>
 > >Thank you for the info. I've got a few quirks, however: When I use .75"
 > > dia (2.35" circumfrence) times 1000 turns, I compute 196 feet of wire,
 > > not 394... Something got doubled. But for some reason, we both got about
 > > 1.2 Mhz (The simple calculator I used probably doesn't account for
 > > self-capacitance)... ???
 > >
 > >At any rate, I'm currently using 2 turns, varying from 2.5 to 3.5 inches
 > > high, and it's working about as well as it was previously (2.5" streamers
 > > -- 3" arcs). I'm beginning to wonder if something is wrong with the coil
 > > itself; Is the 27 Ohms (Measured DC) of resistance excessively high/low
 > > for a tesla coil like this? What about the large amount of
 > > self-capacitance caused by using such fine wire?
 > >
 > >Finally, how can I calculate the capacitance of the small coil of wire I
 > >mentioned that I currently use as a topload? Plus, is there a difference
 > >between the energy in the topload being stored as an electrostatic (toroid
 > >topload) vs electromagnetic (I presume the little coil stores energy as
 > > EM) field?
 > >
 > >On Wednesday 17 September 2003 03:52 pm, Tesla list wrote:
 > > > Original poster: "John H. Couture" <couturejh-at-mgte-dot-com>
 > > >
 > > >
 > > > MCP -
 > > >
 > > > The JHCTES Ver 3.42 TC computer program.
 > > >
 > > > Pri - 2.5" rad -3.5" hg
 > > >
 > > > Pri Cap - .006 uf
 > > >
 > > > Sec - .75" rad - 10.5" hg - 1000 turns - 95.24 TPI
 > > >        5.03 mh - 392 ft lg - 3.69 uh Cself
 > > >
 > > > Fres = 1167 Khz - no topload
 > > >         5.34 Pri turns - 3.1 uh
 > > >
 > > > Fres = 606 Khz - 10 pf topload
 > > >         10.28 Pri turns - 11.49 uh
 > > >
 > > > Streamer Spark = 10"
 > > >
 > > > For other parameters go to
 > > >
 > > >      www.mgte-dot-com
 > > >
 > > > Click TESLA, JHCTES, Go to bottom of Book page.
 > > >
 > > > John Couture
 > > >
 > > > -------------------------------------
 > > >
 > > >
 > > > -----Original Message-----
 > > > From: Tesla list [mailto:tesla-at-pupman-dot-com]
 > > > Sent: Tuesday, September 16, 2003 10:04 AM
 > > > To: tesla-at-pupman-dot-com
 > > > Subject: Primary construction
 > > >
 > > >
 > > > Original poster: The MCP <ejkeever-at-comcast-dot-net>
 > > >
 > > > My two new TDK caps arrived today, meaning that I now have 6nF/40Kv of
 > > > tank capacitor. However, this obviously throws the old setup completely
 > > > out of whack. I've been trying to get resonance again, but failed
 > > > miserably.
 > > >
 > > > So, here are the specs:
 > > > Secondary: .75 inch dia, 10.5 inch wound, 1000 turns, 196 feet of 32
 > > > gauge wire
 > > > Primary is helical, 5 inches in diameter, with 3.5 inches vertical to
 > > > work with
 > > > Tank caps are 3 X 40Kv/2nF TDK caps, X-fmr is 5000/20 NST.
 > > >
 > > > I've tried using JavaTC at classictesla-dot-com, but it's not working.
 > > > After giving up in it, I tried using 2, 3, 4, 6, 8, and 13 turns, none
 > > > of them that
 > > > much better than the other. I've got more 22 gauge wire than you want
 > > > to know
 > > > about and about 10 feet of .375 inch copper pipe to work with. HELP ME,
 > > > PLEASE!
 > > >
 > > > PS, JavaTC says the coil resonates at 750 Khz. Is it on crack?