Re: DC Reactor Setup - don't do this!

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

Original poster: "Metlicka Marc by way of Terry Fritz <twftesla-at-qwest-dot-net>" <mystuffs-at-orwell-dot-net>



Tesla list wrote:
> 
> Original poster: "S & J Young by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<youngs-at-konnections-dot-net>
> 
> In previous posts I mentioned a DC charging reactor needs to have a lot of
> inductance to run at low break rates.  I needed 80 Henry to go below 200
> BPS, for example.
> 
> Since my RSG has an extra set of electrodes so it can act like a SPST
> switch, I thought I would try using it that way with a DC resonant charging
> setup, thusly:  Imagine the RSG has a charging gap and a discharging gap
> which alternate as the rotor turns.  In the charging position, the DC supply
> go through a reactor and de-Qing diode through the charging gap to the tank
> cap.  The tank cap charges in a controlled manner due to the current
> limiting of the reactor.  In the discharge position, the tank cap discharges
> through the discharging gap into the primary.
> 
> The idea is that very low break rates can be used with no danger of power
> arcing, and the reactor can be of reasonable size, say 10 Henry.  This
> actually works quite well, and break rates can be as slow as you want - once
> per hour if desired.
> 
> And now . . . for the rest of the story.  This is why I say don't bother
> doing this.  As the RSG break rate is increased, the dwell time of the
> charging gap gets shorter and shorter.  But the capacitor still takes the
> same time to charge via the reactor.  The result is that the arc across the
> charging gap starts to draw out longer as the RSG RPM goes up.  As RPM
> increases, eventually the arc is drawn out long enough that the discharge
> gap presentation occurs while there is still a charging gap arc.  ZAP!  The
> DC supply now power arcs through both gaps.  In my setup, this happened at
> about 175 BPS at full power.  Reducing the power doesn't gain much higher
> BPS without power arcs.
> 
> So the method is fine if you enjoy wimpy gas burner style streamers, but a
> total failure for the more interesting high BPS robust streamers.

Have you tried an air stream on the electrode position area?

> 
> --Steve