Re: Magnetizing current in SSTCs, my previous posting

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

Original poster: "K. C. Herrick by way of Terry Fritz <teslalist-at-qwest-dot-net>" <kchdlh-at-juno-dot-com>

Steve & all-

 >From simulation, you would seem to be right as to the differing
energy-transfer rates.  In my 1-T-SIM circuit re-jiggered for 2 primary
turns and with C1 (the primary resonator) at the original 1.75 uF, rise
of output voltage to ~maximum takes ~9 cycles whereas with C1 set to 10
uF, the voltage is at maximum at the 3rd cycle.  However, that maximum is
only 50 KV vs. 250 in the prior case.  The peak primary current is 2.7 KA
with resonance (1.75 uF) and 1.25 KA without (but the 1.25 declines to
about 600 A after 4 1/2 cycles and for the balance of the simulation time
of 200 us).  Resonance is at 164 KHz.

In order to achieve the same 250 KV with the 10 uF series capacitor
(non-resonance), I have to up the driving voltage from the original 300 V
pk to 1700 or so, at which level the peak primary current is 7 KA.  Note
that I retain a capacitor because the driving source is unipolar.

So it takes some 60 us in the resonant case and only 18 us in the
non-resonant case for the same peak output voltage to be reached.  If my
conjecture is correct, as to the reason why s.s. sparks tend to be
shorter than conventional sparks, this may be what's significant.  The
conjecture is, as I've mentioned before, that the inertia of the air
surrounding the incipient spark will keep it "bottled up", so to speak,
for some few microseconds.  If, during those few microseconds, the
electrode voltage significantly rises, then the spark will become longer
than otherwise.

So much for a resonant s.s. primary?...  Let's hear comments from others!

Ken Herrick

On Fri, 16 May 2003 08:16:08 -0600 "Tesla list" <tesla-at-pupman-dot-com>
writes:
 > Original poster: "Stephen Conner by way of Terry Fritz
 > <teslalist-at-qwest-dot-net>" <steve-at-scopeboy-dot-com>

[snipped]
 >
 > We're just not sure how the darn thing works. As far as we can tell,
 > a coil
 > with a series tuned primary has to have a slower rate of energy
 > transfer
 > than the same setup with an untuned primary. That is because when
 > you turn
 > on the inverter, you have to ring up both the primary and the
 > secondary. If
 > you like, the energy from the inverter goes into the primary circuit
 > and
 > then couples out into the secondary. With an untuned coil it all
 > goes
 > straight into the secondary.
 >
 > Therefore we think untuned coils ought to perform _better_ in short
 > pulse
 > applications than the DRSSTC would.

[snipped]