Re: Microsim Modeling - SRSG

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

Original poster: "Terry Fritz" <teslalist-at-qwest-dot-net>

Hi Jeremy,

At 07:48 PM 4/28/2003 -0700, you wrote:

> > You need to model the 15/60NST.  See:
> >
> >
>http://hot-streamer-dot-com/TeslaCoils/MyCoils/BigCoil/BigCoilSCH.gif
>
> > By adding winding resistance and reducing the
> > coupling, the short circuit
> > current will be reduced to 60mA just like the real
> > NST.
>
>I'm actually modeling a potential transformer, which
>has no internal current limiting or center tapped
>secondary. I always though the resistance in your
>diagram (2373 on each side of the secondary) was for
>the wire resistance of the secondary, not actually
>intended for current limiting. I measured the DC
>resistance of a 15/60 NST and I got about 3.5K on each
>side. Anyway, (15000V/4746ohms) = 3.16A. Add the 10K
>worth of filter, and it becomes 15000V/14746 = 1.01A
>Still both way too high.
>
>So I'm guessing the real current limiting then comes
>from the primary side variac.

With a potential transformer, you can just measure the primary and 
secondary DC resistance and us that for the model.  Since a PT is not 
current limited, you can put the coupling way up at say 0.995.

For current limiting, PTs need an external inductor or resistance which you 
can easily add to the model.

Cheers,

         Terry