Original poster: Vardan <vardan01@xxxxxxxxxxxxxxxxxxxxxxx>
Hi All,
I have been matching figures 10 and 11 in the SISG pdf:
http://drsstc.com/~sisg/SISG.pdf
to models. It appears that the very low resistance allows the
inductance of the SISG gap to become significant and thus is why
voltage and current are out of phase. It is neat because that gives
the resistance a poorer power factor which makes it run cooler :-))
The gap appears to be a 0.020 ohm resistor in series with a 20nH
inductor. So for power calculations, each gap section dissipates the
primary loop RMS current squared multiplied by 0.020 ohms.
http://drsstc.com/~sisg/SISG-Model-01.gif
http://drsstc.com/~sisg/SISG-Model-02.gif
http://drsstc.com/~sisg/SIDAC-IGBT-3.sch
For my 183 watt test, the RMS primary current is 11 amps, so the
power in the five sections is 12 watts total.
Thus, the gap is loosing about 6.6% of the total coil energy. The
only other major loss would be in my big secondary made from #28
wire that probably dissipates 8 watts as heat. So with 183 watts
in, about 163 watts is making it to the streamer for an efficiency
of 89%. That would actually place an upper limit on the Freau value
of 2.35. To get there (or real close) one needs to reduce the RMS
current and make the secondary reasonably low loss. Lots of
tradeoffs to juggle there...
Cheers,
Terry