Re: Inter-Primary Arcing?

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

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <FutureT-at-aol-dot-com>

In a message dated 8/30/01 3:15:02 AM Eastern Daylight Time, tesla-at-pupman-dot-com 
writes:

> Ok, just like the subject says, I've been getting some arcing between the 
>  primary turns, non-constant, just at odd intervals.  Causes the Cap saftey 
>  gap to fire, then resumes normal, then repeats.
>  
>  The thing is, I've been fooling around with toploads a bit, and this 
little 
>  problem only appears with a specific toroid mounted.  Non of the other 
>  setups do this, even when tuned exactly the same.
>  
>  Any thoughs?
>  
>  Erik.

Erik,  

Generally, when a larger topload is used which has a
large ROC, this delays breakout and delays the quenching, and
there's more time for ionization between primary turns.  Also,
the secondary reaches a higher voltage and may promote 
ionization on the primary.  Do the arcs occur only between
the outer (unused) turns "outside" the tap point?  If so, this
can result due to autotransformer voltage build up in those
turns.  If you're using just a few primary turns, which are
closely spaced, such arcing is more likely.

John Freau