Re: Primary to primary sparking?

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

Original poster: "John Richardson" <jprich-at-up-dot-net> 

Hi Chris,

I've got a few thoughts, which may or may not help.  I am going to guess
that you are tapping at a relatively small number of turns, and that your
turn to turn spacing is on the small side, say under a 1/4 inch.  I've found
this to be a big mistake.  Try to keep turn spacing 3/8 or better.  It seems
at higher power levels, when tapped at low turn numbers, that the easiest
path for energy dissipation can sometimes be the next turn as opposed to the
secondary.  This will especially be pronounced if you are out of tune, which
the lack of streamers leads me to believe.  Are you sure that your tapping
mechanism isn't coming within a hair's width of the adjacent turn?  This
will also cause your problem.  BTW, what is your power source, and what type
of gap are you using?  All I can make out from the picture is a glowing UFO
type of deal, and I'm thinking it's a TCBOR style gap.

John Richardson

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Wednesday, March 31, 2004 7:36 PM
Subject: Primary to primary sparking?


 > Original poster: Chris Roberts <quezacotl_14000000000000-at-yahoo-dot-com>
 >
 >
 > Hi everyone,
 >
 > I just got the coil out to do some pictures, along with trying it out
 > without a breakout point at the top. It seems to not like that, seeing as
 > it had plenty of racing sparks, primary to secondary flashovers, and other
 > problems. I guess it is a result of a higher breakout voltage? Anyways,
 > during one of these pictures, the coil flashed brightly with a huge mean
 > sounding spark. I shut it down and took a look. The spark seemed to occur
 > between the primary tap and the next outside winding, seeing as that's
 > where the scorch marks are. So why would the coil want to do that?
 > Shouldn't the tap and the primary be at the same polarity? Even if they
 > were, wouldn't it be easier to have the current go around one more turn
 > instead of blasting through the air? Whenever I fix this thing from
 > sparking in one spot it starts in another... except for all off the top.
Is
 > that so hard for it to do? Oh well, it at least made the ! photo look that
 > much better! =D
 >
 >
<http://hot-streamer-dot-com/temp/P1010077.JPG>http://hot-streamer-dot-com/temp/P101
0077.JPG
 >
 >
 > -Chris
 >
 >
 >