Re: A few quick questions....

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

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

Alan,

Yes, an NST can draw more than its rated power especially if you
power it with a step up variac (260V).  With an LTR cap, and step
up type variac, a power factor corrected NST can draw double the
rated power or more.  A resonant sized cap will also increase the
power draw when using a step up type variac.  If you don't use
PFC, then it will draw an even higher current.  (it can be surprisingly
high in fact.)
>  
>  2. Power factor correction capacitors for the NST. It's a Tunewell
>  transformer and the makers suggest using a pfc cap of 40uF. Is it actually
>  worthwhile using a PFC in TC work.....if only to reduce the electricity
>  bills ?! 

It's more important in the US where we usually use 120 volts with
NST's.  If we don't use PFC, our fuses or breakers may blow depending
on the NST and ac feed circuit rating.  PFC also reduces power wasted
in the wires, lets you use a smaller variac, etc.

>  
>  3. Positioning of the NST. I'm thinking of putting the MMC etc under the
>  primary and secondary coils as in the most popular TC designs but was
>  wondering if there are any undesireable effects of having all this 
equipment
>  sitting in the magnetic field of the primary ? Particularly a huge lump of
>  soft iron in the form of the NST !  If the NST is under the coil so that 
the
>  mains leads run across the floor has anyone had a secondary strike the 
mains
>  leads ? At the moment I'm leaning towards having the NST and NST protection
>  filter at a distance from the coil and running the EHT leads across the
>  floor....

Caps and NST can be placed under the coil, but not too close to the
primary.  http://hometown.aol-dot-com/futuret/page3.html       for a photo.

John Freau