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Primary Qs


From: 	Malcolm Watts[SMTP:MALCOLM-at-directorate.wnp.ac.nz]
Sent: 	Monday, September 22, 1997 2:49 PM
To: 	tesla-at-pupman-dot-com
Subject: 	Re: Primary Qs

HI John,
          I'm not losing too much sleep over the one transformer I 
have lost since I learnt a lot from the exercise and the plan now is 
to wind a 2kW model using the same core.

> From:   FutureT-at-aol-dot-com[SMTP:FutureT-at-aol-dot-com]
> Sent:   Monday, September 22, 1997 4:00 AM
> To:     tesla-at-pupman-dot-com
> Subject:    Re: Primary Qs
> 
> In a message dated 97-09-22 01:11:06 EDT, you write:
> 
> << snip> I got far better results in both types
> > of primary with the lower frequency resonator. The only reason I can 
> > attribute that to is the higher primary Q I got with lower frequency 
> >running. The primary cap was also identical and single shot 
> > measurements showed output voltage to be roughly the same. Both 
> > resonators are wound with large enough wire to discount secondary 
> > losses from the mix. I was getting solid three feet strikes with a 
> > 25nF CP primary cap from the low frequency resonator but only about 
> > 2-1/2 feet from the higher frequency one.
>  
> > Malcolm >>
> 
> Malcolm,
> 
> I'm sorry to hear that your neons were snatched all too early by the
> grim reaper, and I'm waiting to hear of the mechanism of their death. 
> Your low frequency observation is intriquing.  Perhaps my sync-TC is 
> benefiting from its ~90kHz operation?

I would think that is _very_ likely. Also the lower loss of the sync 
gap as outlined earlier.
    There is no doubt my neon was killed by a "kickback". For 
months/years I have been wondering how a voltage higher than that 
generated by the transformer could appear across the transformer 
terminals (resonant charging and wide-set gaps aside). The answer 
lies in the impedance of the transformer at the RF frequencies. If 
some energy still remains in the sec of the coil after the gap has 
gone out, it is coupled back to a series-tuned primary which is now 
in series with an ultra high impedance presented by the transformer.
My filter setup prevents the transformer ringing with the filter caps
but in the process, I have boosted the impedance across the 
transformer terminals. I should have used filter caps big enough to 
limit the rise of a moderate amount of energy that could be fed back 
while at the same time ensuring an unfavourable ring frequency with 
the transformer. The only simple answer I have right now is bigger 
filter caps. Back to the lab.

:(
Malcolm