Re: Big SISG Coil First Light - New Charging Circuit Works Too!!

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Barton B. Anderson" <bartb@xxxxxxxxxxxxxxxx>

Hi Terry,

Wow, neat!

I wanted to comment on your cap cosmetics. That is just - cool. So, 
you've got basic CD's inside a square plastic tube filled with foam. 
Who would have thought? I was just getting over being a little p***** 
off with myself (I blame you). You were smart enough to build this 
nice square cabinet with your SISG coil and I built this round 
thing-a-ma-jig. Round sucks! Next time, I'm going the "Terry Route". 
Low and behold, you now throw this new cap containment system in 
front of me!!!! I'm back to being "p***** off" at myself - again!!!

All kidding aside, great job! Your SISG is just what I need to get 
started into the SSTC world of coiling. Thanks for all the pics and 
documentation.

Take care,
Bart

Tesla list wrote:

> Original poster: Vardan <vardan01@xxxxxxxxxxxxxxxxxxxxxxx>
>
> Hi,
>
> I finally got the larger SISG coil's electronics going today.  It 
> works good!!! :-))
>
> This coil uses a new SiSG charging circuit shown here (probably work 
> for standard gap coils fine too):
>
> http://drsstc.com/~sisg/files/BigSISGCoil/BigSISG-Schematic.gif
>
> The charging circuit gives the coil a fairly surprising BPS 
> range.  It starts at about 70 volts at roughly 60BPS and goes "up" 
> from there.
> Its nature is like that of an async system.  It seems to work pretty 
> much as predicted.  I did not spend much time on models for it yet 
> until I could test to see if it worked at all.
>
> There are pictures here:
>
> http://drsstc.com/~sisg/files/BigSISGCoil/P8070190.JPG
>
> http://drsstc.com/~sisg/files/BigSISGCoil/P8070191.JPG
>
> http://drsstc.com/~sisg/files/BigSISGCoil/P8070193.JPG
>
> http://drsstc.com/~sisg/files/BigSISGCoil/P8070195.JPG
>
> There is a VCD format movie here:
>
> http://drsstc.com/~sisg/files/BigSISGCoil/BigSISG.mpg
>
> If you can't get it to play there is a rougher but more basic MPG here:
>
> http://drsstc.com/~sisg/files/BigSISGCoil/BigSISG-alt.mpg
>
> If it is real busy, try back a bit latter.
>
> The capacitors are MMC in a length of plastic gutter pipe.  I could 
> have put them all into one the same size.  I may get more caps and 
> do that just to save room in the final coil.  I filled them with 
> polyurethane foam which works well.  I will hard epoxy the ends someday...
>
> The coil itself is just the old DRSSTC step up for now too.
>
> The SISG is Mark Dunn's board which works fine.  It can easily hit 
> 24 inches.  I have into measured much yet but the new charging 
> circuit should have a very good power factor and all.  The resistors 
> burn off heat but it will have a fan ;-))  That is a small cost for 
> the simplicity and I don't think it can be blown up.  The SISG IGBTs 
> seem to run cold.  I will have to test it to see if I might want to 
> go to 225W resistors just to keeps things cooler.
>
> The bang power is 1.54 joules at say 185 watts at 120BPS.  It seems 
> like one could very easily scale it up but I have not gotten more 
> IGBTs yet to fill more boards.  The 237.5nF primary cap seems to be 
> a nice balance of primary peak current, energy, Fo, and power.  But 
> there or probably things that could be optimized since the resistor 
> values were pretty much a guess.
>
> But the main thing is that the charging circuit does actually work 
> very well!!!
>
> Cheers,
>
>     Terry