Re: Fwd: Re: Calculating streamer breakout of top-loads

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

Original poster: "Gerry Reynolds" <gerryreynolds-at-earthlink-dot-net> 

There are certainly a lot of variables as you state below.  If spark length
prediction is going to be based on power only,  I would think that using
sparkgap throughput power would at least be closer to reality.  Simulation
results that I have seen in the archieves that Richie Burnett has done for
static spark gaps sheds some light on this but is certainly not the total
answer.  Terry Fritz has a good web page that talks about matching the
output impedance of the secondary to the streamer impedance that maybe sheds
light on some of the points you bring up.

Gerry R
Ft Collins, CO


 > Wallplug draw. The fact that operating results often don't match the
 > theoretical result probably says something about the electrical coil
 > parameters as well as the power supplies used. The basic recipe for a
 > given (input) power level appears to be:
 >
 > - highest possible output voltage from the coil to give reach and
 > induce streamers from far objects (implies high energy shots which
 > for a given power level translates into low breakrate)
 >
 > - very high output current implying a high capacitance in the
 > secondary system (a conflicting requirement with the the first point)
 >
 > - high enough breakrate to promote streamer growth while not
 > restricting it through having such a high degree of ionization as to
 > clamp output voltage excessively (conflicts with requirement 1 again)
 >
 > The question is, where does the balance lie? There appears to be
 > little doubt that there is an broadly-defined inflection on the
 > breakrate curve as breakrate is reduced. from past experience I
 > suspect that the dependency on input power is minimal. That leaves
 > the V/I ratio in the secondary to be explored. My tabletop design
 > (yet to be fired) aims for a reasonably high capacitance in the
 > secondary system, yet not so high as to reduce output voltage too
 > much (don't ask me to quantify what I mean by "too much" - I have the
 > figures on the back of an envelope at home somewhere). The breakrate
 > will be about 100 (2 Fmains for me) and I will use as large a primary
 > capacitor as I can get away with while still having the primary gap
 > fire reliably at about peak transformer output voltage. For my
 > transformer (5kV, 30mA) I remember calculating a figure somewhere
 > around 0.7 (0.9?) Joules. Finally, minimizing gap losses are all-
 > important. You can probably guess how I've gone about doing that.
 >
 > Malcolm
 >
 >