Re: Tesla Coil Tricks

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Original poster: "Harold Weiss by way of Terry Fritz <twftesla-at-qwest-dot-net>" <hweiss-at-new.rr-dot-com>

Hello All,

On the Zinc wicked candle trick, the hardest part is to find the 
candles.  These were used for small votive candles.  They almost always 
have a square metal wick holder on the bottom of the candle, which makes a 
great contact point.  The wick can be identified by looking at the core of 
the wick, if it is black (old) or shines (fresh cut), it is zinc.  These 
candles have fallen out of favor with candle people as they like to leave 
soot marks on ceilings. (Good for us!)

When I first did this experiment, I had the coil connected with a parallel 
primary system.  Most coils today are series connected, as it is easier on 
components.  I also had a steel 6" sphere for topload.  I made one mistake, 
I did not have any way to catch spilled wax and made a big mess on the 
sphere/primary.  Streamer length at the time was 10-12", which was later 
increased to 18" with higher Q caps.
Power was supplied by a 7.5/30 NST.

With the candle mounted on the sphere, I would get from .5-5mm 
fireballs.  I noticed that the candle seemed to burn faster than 
normal.  This version produced larger balls than the car tire that I would 
burn. ( was more plentiful than candles)  Car tire averaged .5-3mm, candle 
averaged 2-5mm, for my coil setup.  Drawing power arcs to the car tire that 
I used, seemed to produced more balls, but it only works when drawn thru 
the heat plume/soot cloud above the flame.  I found that about 2/3 of max 
strike distance seemed to work best.  With more power added, balls would 
get larger.

I used to work in the still air in my basement, but as my coils became 
bigger and better, I had to move outside for safety.  Trying to get a dead 
calm night is hard at best.  I have tried a modified candle, but not a zinc 
one.  I think the biggest problem is the soot cloud gets blown away from 
the streamers.  In other similar experiments a 18-20mm ball was produced, 
that floated out about 3' and splattered like an egg on a wall.  I did have 
a 1cm ball pop out of the side of my 6" coil while I was tunning it, 
causing two turns to then arcover.  I had purposly built this secondary to 
explore severe overcoupling.  The cause on this one may have been best 
described in Tesla's patent.

I recently found about 1 1/2 dozen suitable candles in the basement, and 
sent 4 to Dan.  He tried them on a grounded rod, drawing the streamer to 
the candle with poor results.  This would be similar to natural balls, and 
why we don't see them often.  I am also thinking that a mushroom or sphere 
terminal may be the most useful in this type of experiment.

Good luck to anyone trying this experiment.

David E Weiss