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Re: Coil only arcs when safety gap fires (what the *%@?)

Original poster: Terry Fritz <vardin@xxxxxxxxxxxxxxxxxxxxxxx>

Hi,

At 05:55 PM 8/12/2005, you wrote:
Grand Master Coilers, 

I still have all my fingers ;o)))


I have my first brand new coil running on a 15/30 NST with a SRSP at 120
bps.


"My" "first coil" made a 1/8 inch arc and then went up in smoke. >:p

I just fired it up for the first time and it is behaving oddly. After
tuning I am only getting very small arcs and only at the firing of the
safety gap (set just beyond the point where the NST at normal output would
cause an arc).

Have you tried "tuning" the coil buy trying different primary tap points? One usually has to "search" for a "sweet spot". I guess you have...

Also, the sync gap may be in the wrong position. You may have to turn the motor to different positions, say 10 degrees apart, to find the best firing time for the gap. It may be turning at 30.0000 rpm, but it might be 90 degrees wrong...

You may want to just turn the sync motor off and set the gaps real close and work on the primary tuning first. A pointy wire off the top terminal should help you see where the optimum sparks occur. that way you can work on one variable at a time.


 My cap tank is actually 2 times resonance which I know is quite large (I
was having trouble finding a cap match and so I went with what I could find
until parts come back in stock).

Ok, Probably the other two (tuning and spark gap firing position) are more important right now. The right size capacitor will be "next"... Be cautious if the transformer gives off a loud "hum"....

Might this effect my operation thusly? My
only other guess is coupling, which I have yet to fully understand. My
secondary sits 1.5 inches above my primary plane.

Don't worry, that is fine for now. When the other three things are fixed, you may want to fiddle with coupling, but not right now.


Any thought on the matter would be met with wild ululation :)

"ululation"... = To howl, wail, or lament loudly... Whaa, you a lingustists or something :o))))

Fix the tuning first, then play with the gap timing. The right size cap with fix the rest. Be double careful when fiddling with the coil that the power is off and the thing is discharged!!!

Cheers,

        Terry



Ethersmith the Apprentice