Re: rectified nst's and hookup

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Original poster: "Dr. Duncan Cadd by way of Terry Fritz <twftesla-at-uswest-dot-net>" <dunckx-at-freeuk-dot-com>

Hi Marc!

>let me point out the reason for all this, the triggered gap works
great
>in sync. with the ac line frequency. firing at 120bps reliably with
the
>dimmer giving a nice fine tune to the phasing, i apologize for saying
>120hz in prior posts

Could also use 120pps, 120cps or 120c/s, or refer to the period, 8,3
milliseconds.  As you please.  The US mains supply frequency is not
going to change.  After a near quarter-century of high-level academia
which has included two Fellows of the Royal Society and spitting
distance of two Nobel prize winners, I have little time for mere
pedantry.  "If you have understood me well enough to correct me, you
have understood me well enough."

>i want to rectify the nst so i can try the triggered gap at variable
>frequency's and i am building a trigger drive that will fire from
>0-100khz with adjustable pulse duration's from 10us-1s.


Look forward to seeing it!

>i don't know exactly what if anything will be shown by all this

Doesn't matter!  Good science frequently begins with the question
"what if?" and a lot of the time (believe me, a *LOT* of the time) the
answer is "nothing".  For each procedure which worked during my PhD
years, I'll bet there were at least ten which didn't, maybe twenty,
and there might even be some of my colleagues who'd say I had it easy,
though it took me a year more than average to get my thesis.  If you'd
never seen the inside of scientific research you'd be forgiven for
thinking it was all eureka moments, but you only get the successes by
eliminating the failures.  Real life research is more depressing than
glamorous, and has more to do with endurance than brilliance.

>but i
>would like to mess around with getting the gap to quench at very high
>break rates? maybe trigger my 33khz coil at 33khz, what would happen
>then?


Only one way to find out for certain!  I too find high break rates
really interesting.  6000 cycles per second is the fastest I have done
to date - yep, a mere 167 microseconds for each charge-discharge
cycle, equivalent to 50 radio frequency cycles at 300kc/s.  The sparks
are short, highly-branched, dendritic fractals and they move very
rapidly.  Also, they hiss venemously!

>i have a 2 x .15uf 10kvdc cap, will this work for the filter cap?


With a 12kV NST plus bridge rectifier, you'll need them in series to
get the voltage rating up, so you'll have only 75nF, output volts are
likely to be around 16-17kV max and very dependent on the loading as
NSTs have intentionally poor regulation.  With a current draw of
around 50mA (I think this is about right?) it will give you some
smoothing action, especially if you follow the cap with a resistor of
a few k-ohms, suitably rated.  Let's say 10k at 40W, which you could
make as an MMR.  You'll lose around 500V across such a resistor but
the dc output will be a bit smoother for it.

>i'm having fun with the triggered gap, it has opened up a new aspect
of
>coiling for me.


Treasure that "fun".  "Real" scientists often have very little.  You
may find that the "fun" is the most precious outcome of the
experiment.

>i will try to choose my words more carefully in the future because
some
>find it more enjoyable to find faults then doing or helping with
actual
>coiling experiments these days.

Maybe they don't get out much.

Dunckx