Re: NST failures

["Malcolm Watts" <M.J.Watts-at-massey.ac.nz> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

Hi Trent,
          What you say about failure of NSTs in ordinary 
service with regard to lead lengths is interesting 
because......

On 2 Aug 00, at 22:52, Tesla list wrote:

> Original poster: "Trent Mullins" <neontrent-at-earthlink-dot-net> 
> 
> Hello Brian and Dan,
> 
> For whatever reason, NST failure IS DEFINITELY directly related to lead
> length.  As mentioned below, the side with the longer lead will fail first
> (if failure is inevitable).  Most installers and designers configure NST
> placement in the middle of the series loop.  One common way to avoid long
> lead length is to "mid-point ground" the NST.
> 
> If you can visualize an NST placed dead center between a length of neon
> tubing, connected with short leads to the unit on each side, then the end
> unit on each side is wired directly to ground.  This setup works well with
> properly loaded NSTs and a good ground.
> 
> Overall, I would recommend keeping lead lengths as short as possible for
> neon applications, but as far as Tesla applications, I doubt of any
> significant benefit.

I think there most definitely is a benefit in keeping the 
leads short, *especially* in coiling applications.
      Consider a NST powered coil: if the lead length between 
the transformer and the gap is minimal (like ideally zero), 
the main gap doubles as a safety gap. If the leads are long 
however, you now have some arbitrary impedance between the 
transformer and gap and the gap can no longer perform this 
function. Running the transformers with minimal lead lengths 
is now the only way I run them and I haven't lost any (no 
filters, safety's etc. for the several years I've been doing 
this. To prove the point I once smoked another type of 
transformer (which up until that time had performed 
flawlessly) when on the one occasion I ran a twisted pair for 
a couple of metres from the transformer to the gap. 


Regards,
Malcolm
<snip>