Finished populating and have begun testing of my Mark Dunn SISG board... (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Wed, 27 Jun 2007 17:21:22 -0700 (PDT)
From: Brett Miller <brmtesla2@xxxxxxxxx>
To: tesla@xxxxxxxxxx
Subject: Finished populating and have begun testing of my Mark Dunn SISG
    board...

All,

I received my shipment from Digikey today which
contained the rest of the parts I needed to finish
populating my nice Mark Dunn SISG PCB.  I will remind
the list that before I jumped into ordering his board
and tampering with the technology, I read Terry's
original paper about 5 times.  Then I proceeded to
build and test 3 of my own discrete stages using perf
board.  This also have me the opportunity to design a
nice resonantor and primary to use as a test stand for
my future higher power SISG work.

Anyway, I went ahead and populated the board:

http://www.hot-streamer.com/brett/temp/mark_pcb_populated.jpg

...I still don't have the heat sinks, but I intend on
purchasing the exact sinks Mark and Terry used, since
they are perfect for the SUPER TO-247 package and are
made to fit on the PCB as is...unlike the massive
assortment of randomly shaped heat sinks in my SSTC
junk box.

After jumpering in the board for testing (*very* short
run times, since there is nothing to control IGBT
heating) I found that my current setup (a full wave
rectifier into a 1k 100W power resistor) did not reach
a high enough voltage to fire all four sections.  Once
I tapped into the 2700v point on the PCB, the gap was
able to begin firing at right around 110v on the
variac.  Quite violently I might add, and I just about
wound up having to change my pants.  Terry was right
about the sudden startup being a "scary" feature, it
sure is once you start dealing with 3 out of the 4
sections.  I can't wait to see it at 8!...certainly an
outdoors or big warehouse thing only.

Here's a video that shows the rapid turn-on at
110v...it's hot-streamer, so you will want to right
click and save to your pc before watching, since it'll
probably be too slow to stream:

http://www.hot-streamer.com/brett/temp/3sections_1foot_gap.avi

Here's some hits to 15" with only 3 segments of 900v
SISG...this video is a bit smaller:

http://www.hot-streamer.com/brett/temp/2700v_15inch.avi

It's pretty exciting to already see this kind of spark
length on a 4.5" x 12.5" 31AWG resonator while only
using 3/4 of the single board's power!

Here's a semi-ok still of some 13" or so powerarcs...I
may have shook the camera a bit, which is bad when
going without the flash:

http://www.hot-streamer.com/brett/temp/SISG_arc_june27.jpg

Well, next step is to switch to a better (read higher
voltage) pulsed DC tank circuit, which I may do
tonight if I have time.  Since I probably won't I will
try to do it sometime in the next week or so.  My wife
and I are going on our 6th anniversary vacation in a
few days, so if I don't get any major SISG work done
pretty soon, then I'll be posting again in the middle
of July.  

Around that time I also hope to have some current
transformers here so that I can study the primary
currents.  It will be especially interesting when I
get a higher voltage charger and can add some of my
own FGL40N120AND segments to this board and see how
the current 120 vs 240 imbalance effects things.

I know for a fact that there are at least 5 or 6
people here interested in this.  

Thank you to Terry Fritz, Mark Dunn, John Freau, Steve
Ward and everyone else!

-Brett




       
____________________________________________________________________________________
Sick sense of humor? Visit Yahoo! TV's 
Comedy with an Edge to see what's on, when. 
http://tv.yahoo.com/collections/222