[Prev][Next][Index][Thread]

Re: Neon Question

>Date: Wed, 27 Mar 1996 22:09:39
>To: USA-TESLA-at-usa-dot-net
>From: lcwang-at-students.wisc.edu
>Subject: Re: Neon Question
>
>At 07:12 AM 3/27/96 GMT, jim fosse wrote:
>>Lawrence,
>>        Can you give more specs for your coil? Like, enough that I
>>could build it?
>
>For the power supply, I've got one 15-30.  The primary is made of six
ten-foot one-inch-wide strips of aluminum flashing ("welded" together with a
12-60 :) ) connected together and hot glued to a 1/8" thick piece of
uninsulated plywood, such that the inner diameter is 18 inches and the
spacing is at 0.5".  The primary cap is sixteen large jam jars inside a big
Tupperware container (salt water cap.)  For the spark gap, I have ten
three-inch sections of 1/2" hard water copper pipe (for a total of nine
gaps), each set at some distance less than 0.1 inches.  They are mounted on
a piece of plywood with the help of some double-sided Scotch tape (how the
heck do you guys measure out 30 mils and keep the rods just that far
apart?!?!).  At the moment, I have no protection for the neon transformer
(no safety gap, no bypass caps, no RF chokes;  I have neither plans nor
money.)  All this crap is connected with 16 AWG hookup wire (yeah yeah screw
the skin effect;  my system Q would still be miserably low with RG-218,
which is impossible to find.)  The secondary is currently 2100 turns of #26
Heavy-Armored Polythermaleze (made by Belden) on a 2.175" O.D. piece of
thick-walled PVC pipe (hey, I got it for free, ok?)  The winding is about 50
inches long.  For a toroid, I put a big caribeaner on top and covered the
knurled part with black electrical tape.  The "ground" is a 4 foot by 10
foot metal screen suspended off of my vinyl covered basement floor by four
small styrofoam cups.  I didn't bother to ground the center tap of the neon;
is this real bad?  I also use a 1 kVA autotransformer to control the voltage
on the autotransformer.  I have never gone above the 50% setting, except for
the very first time I applied power to the system.  That time I went up to
about 60% before four of the jam jars shattered and spilled brine all over
the place.  Now , whenever the gap fires, I still have big, vicious-looking
purple sparks that run from the salt water under the oil to the inside of
the jars.  On the advice of the esteemed Richard Quick, I am collecting beer
bottles for use in the cap instead of the jam jars.  Also, I plan on
building a new secondary:  I have a polyethylene form that is quite thin and
is about 52 inches long and has on O.D. of 12 inches.  I plan on winding a
48 inch winding with #20 AWG wire;  this gives 1267 turns and a resonant
frequency of 102kHz, theoretically.  The new secondary, along with the 0.025
uf CP cap (!!!) that I just ordered through Scott, should probably work a
lot better.  I think now that my cap might be holding me back, jim, since I
can't go above 50% power without messing it up.  The best output I have ever
gotten is about 15 cm of purple-colored, relatively straight and very
short-lived sparks.  On the other hand, there are all kinds of whitish
sparks running down the length of the secondary winding, but not
slow-changing and curved like the ones in the RQ video.  I can't really seem
to tune the system:  more turns just seems like more spark all the way down
to one turn.  At first, I thought that I might not be filling up the cap;
this is why I suspected that the 15-30 was not doing it's job.
>
>-Lawrence
>