secondary suicide?

From:  Bert Hickman [SMTP:bert.hickman-at-aquila-dot-com]
Sent:  Saturday, April 11, 1998 10:08 PM
To:  Tesla List
Subject:  Re: secondary suicide?


Sorry to hear about your secondary's self-destructive tendencies! How
did you prepare your coilform prior to winding, what gauge/insulation
magnet wire are you using, and what are the diameter and active coil
length of your secondary? Also, what's the capacitance of your primary
cap, and the power level (or faceplate voltage/current rating) of your
HV transformer? 

Offhand, I'd suspect that you may be getting arcover to an improperly
prepared coilform. Alternatively, you may be inadvertantly overvolting
your secondary if it is too short for the power level you're running at.
Maximum turn-turn voltage stress occurs in the lower half of the
secondary, so if you have insufficient voltage stand-off capability, it
will show up here first.  Providing the above information should help us
determine the cause.

-- Bert --

Tesla List wrote:
> ----------
> From:  Jeff Corr [SMTP:corr-at-enid-dot-com]
> Sent:  Saturday, April 11, 1998 1:43 PM
> To:  tesla-2 list; tesla list
> Subject:  secondary suicide?
> Last week I ran into a problem I had never seen before.
> About an inch up from the bottom of my secondary,
> an arc started to appear when the coil was running
> between 5-10 turns of wire.  This started melting the
> PVC of course, so I turned it off and unwound the coil
> up unto that point, removing those turns.  All went fine
> until last night where the same thing occurred about
> half-way up the tube.  I put solder between the space which
> was arcing (about 8 turns).  I figured it would stop the arcing
> at least by shorting those turns out of the secondary.
> It did there, but 10 minutes later another "leasion" formed
> in another place on the tube about 4 inches below the
> second one.  What is causing this??
> Jeff Corr
> 2114 Monitor
> Enid, OK 73703
> http://www.harvestcomm-dot-net/personal/corr/