Re: Poulsen help

["Steve Young" <youngs-at-konnections-dot-com> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

Mike,

I wonder if your setup is functioning as a relaxation oscillator, and not a
true Poulsen oscillator.  Perhaps you could determine the answer by
examining oscilloscope waveforms.  A relaxation oscillator would stil
shock-excite your TC and give some output.  Just a thought.
--Steve

----- Original Message -----
From: Tesla list <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Monday, August 07, 2000 5:00 PM
Subject: Poulsen help


> Original poster: "Mike Nolley" <nolleym-at-willamette.edu>
>
> In the last week I've been tweaking the Poulsen arc TC quite a
> bit.  However I'm afraid I haven't been successful at producing longer
> sparks. I am still hovering at around 5 inches max, as I said, about
> the same length and quality as a large flyback type oscillator.  I tried
> lowering the supply voltage to 1000 volts and reducing the ballast
> resistance.  The results here were interesting:  instead of the 5-10k of
> resistance I normally need to prevent the gap from "looping" (blowing out
> into an arc), I only needed 500 ohms.  This decreased the arc length while
> increasing its current substantially.  Decreasing the distance between the
> blow out magnets didn't seem to help.  Also, it seems that the only way
> the coil will put out anything significant is if it is operated in bipolar
> mode.  The classic configuration results in <1 inch sparks.  Perhaps I'm
> not actually operating at the fundamental frequency. . . It could be that
> I'm actually getting the secondary to resonate at a partial.  Could anyone
> give me some pointers?  Here are the specs again:
>
> 2kv supply voltage -at- 1-4A limited by a 10K resistor
> .0165 uf capacitance (5 1600V 3.3nf MMC capacitors in parallel)
> 22 turn primary, tapped every 1.5 turns usually resonates at around 13-15
> turns
> 800 turn secondary
>
> I'm thinking that the only way I'm going to get longer sparks is
> by increasing the voltage two or three times, and increasing the
> resistance to 40K or so.  Even if it doesn't work it will be
> interesting:  since it isn't very often that one gets to operate CW at
> 8kv. . .   Thanks in advance for any help.
> --Mike
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