Re: sec input impedance

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

Original poster: "Malcolm Watts by way of Terry Fritz <twftesla-at-qwest-dot-net>" <m.j.watts-at-massey.ac.nz>

Hi Jan,

On 31 Jul 01, at 12:50, Tesla list wrote:

> Original poster: "Jan Florian Wagner by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <jwagner-at-cc.hut.fi>
> 
> Hi,
> 
> >  http://www.abelian.demon.co.uk/tssp/
> hmm that looks interesting...!
> 
> > Yes, but what happens when the sparks start flying? 
> > Remember, for a 
> > 1/4 wave transformer, Zo = SQRT(Zbase * Ztop).
> 
> I always thought the task was to match the primary to secondary and
> then secondary to the TC secondary input impedance? Disregarding Ztop /
> Zout by disregarding streamers?

I don't think you can disregard anything. How can you possibly match 
primary to secondary without taking secondary loading into account? 
You start with the terminating impedances at each extreme and work 
out a matching network which has to match them. This applies to 
everything - right down to a single IF stage in a radio. Assuming a 
single transistor amplifying stage, you find that the collector load 
has an impact on the impedance seen at the base.  
 
> And, second question: which one is preferrable, direct base feed through 
> a step-up/matching transformer, or magnetic coupling where the
> coil in the full-bridge is a helical TC primary coil? I'd imagine the
> latter one is much harder too do, insulation & coupling wise? Which one is
> "better"?

Technically they are equivalent. Pick the one which presents the 
least mechanical and insulation problems.

> Many thanks,
>  - Jan
> 
> --
> *************************************************
>  high voltage at http://www.hut.fi/~jwagner/tesla
> 
> 
> 
>