Re: Coil Doesn't Fire

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

Original poster: "Bart Anderson" <tesla111-at-sbcglobal-dot-net> 

Hi Jim,

Well, interesting (your are breaking out, although you have to beg for a 
spark). Probably, loose coupling and tuning is the real problem. You may 
want to use some scrap wire to add 1 or 2 inner turns as per my previous 
post (scrap wire for a quick test). If that dramatically improves the 
output, then make it pretty and robust, and don't forget to retune.

Take care,
Bart B.



Tesla list wrote:

>Original poster: JBarrett-at-trumbullcorp-dot-com
>
>Man you guys are a wealth of good information! Thanks!
>When I power up my coil the spark gap immediately begins to fire. It is 
>pretty loud too. I had it set to 1/4" and tried to open it up slightly 
>until it wouldn't fire at all, or the air psi applied would quickly quench 
>the spark. My gap consists of two solid brass dowels mounted in 1 inch 
>thick plastic shaped in the form of an U. A set screw in the plastic 
>allows for adjustment of the two dowels and air is applied through the bottom.
>
>The only way I can get any fire at all from the torrid is if I suspend a 
>ground wire to within two inches of the torrid. Even then the corona is 
>very very small.
>
>As far as the caps go I must admit ignorance on this. I purchased these 
>caps from Ebay because I thought they were similar to the ones Terry Fritz 
>uses. The funny thing about these caps is nobody seems to know anything 
>about them. Each cap has a 10 meg bleeder resistor .      Ebay Description 
>Below
>Description
> > > >SEALED BAG OF 100 PANASONIC HIGH FREQUENCY
> > > METALLIZED
> > > >POLYPROPYLENE FILM CAPACITORS. PER PANASONIC'S DATA
> > > >SHEET "DESIGNED FOR APPLICATIONS WHERE HIGH
> > > FREQUENCY
> > > >AND HIGH PULSE ARE REQUIRED". .0043 MICROFARAD,
> > > >2500VDC, PANASONIC PART # ECW-H15H432F7
>
>.  Maybe this will shed more light on the situation.
>
>Thanks Again for everyone's input.
>Jim Barrett
>
>
>"Tesla list" <tesla-at-pupman-dot-com>
>
>09/16/2004 07:36 PM
>To
>tesla-at-pupman-dot-com
>cc
>Subject
>Re: Coil Doesn't Fire
>
>
>
>
>Original poster: Esondrmn-at-aol-dot-com
>
>In a message dated 9/15/04 11:52:36 AM Pacific Daylight Time,
>tesla-at-pupman-dot-com writes:
>
>
> >Original poster: JBarrett-at-trumbullcorp-dot-com
> >
> >
> >Hey I bet no one has had this problem. Just kidding!
> >
> >Transformer:
> >12,000 Volt 30 ma
> >
> >Caps
> >Panasonic ECW-H 0.0043uf +- 3% W.V. 1500 VP-P 2500 VDC with a 1 megaohm
> >bleeder resistor across each cap. 8 in series 12 parallel.
> >
> >Secondary
> >21" of 22 guage wire on a 4 1/2 inch PVC Pipe
> >
> >Primary
> >14 turns of 3/8 copper tubing mounted on 3/4 inch plastic risers set at 30
> >degrees. The inner radius is 5 1/2inches.
> >
> >Torid
> >22 inch major radius of 4 inch flexible dryer duct mounted on aluminum foil
> >covered 1/4 inch plywood.
> >
> >Spark Gap
> >Air cooled at 25 psi
> >
> >Grounding
> >2- 4 foot ground rods driven into ground and soaked with h2o.
> >
> >I believe my caps are the major source of the prolem however someone
> >pointed out that my transformer is a little small too.
> >Any other thoughts?
> >
> >JIM
>
>
>Jim,
>
>What is the coil doing?  Is the primary spark gap firing?  With a low power
>coil like this, you don't need a blown gap.  A static gap made of 1.0"
>copper tube sections about 3.0" long would work fine.  Use about six copper
>tubes with about .020" to .030" gap between each.  Then start by using only
>about four of these gaps to see if you can get the coil running.  It is a
>good idea to use a small fan for cooling on the gap.
>
>If the gap doesn't fire, either something is wrong with the transformer,or
>the caps or it is not hooked up correctly.  I am not familiar with the caps
>that you are using.  Are these the good poly/metal foil caps?  The total
>equivalent capacitance is only .0065 ufd.  That is kind of small for a coil
>of this size.  Some quick calculations show the coil should tune as is with
>the primary tap set at about turn 12.5.
>
>I see Gary mentioned the bleeder resistors.  That is a good catch.
>
>Ed Sonderman
>
>
>
>