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Original poster: "BRIAN FOLEY" <ka1bbg@xxxxxxxxxxx>

Hi, you just answered my newest questions! many will want to try this new
stuff, i am interested also. cul brian f.
----- Original Message -----
From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Tuesday, May 23, 2006 11:16 AM

> Original poster: "Mark Dunn" <mdunn@xxxxxxxxxxxx>
> Followers of the SISG Thread:
> A few weeks ago I contacted Terry and offered my coil as a full scale
> test unit for the SISG concept.  My coil is MOT powered with a full
> bridge rectifier and filter caps to provide a DC based system.  I then
> use DC resonant charging to charge up a 38 nF Tank Cap and fire a 4.5"
> dia X 21" coil with a 5" X 16" (John Freu) Toroid and a 460 BPS RSG.  It
> was clear from the outset that this medium power application would
> require generous heat sinking of the IGBT's.  Since my primary operating
> voltage is ~ 17 kV I would require ~ 20 of the SISG circuits to replace
> my rotary spark gap.  Recall that each SISG circuit is set at 900 volts.
> I consulted with Terry and designed a PC board that contains (4) SISG
> circuits.  Thus I would need (5) boards in series for my application.
> Last week I ordered these boards and some extras.  I also made a bulk
> order for the 800 amp IGBT's from Singapore.  I ordered in bulk to get a
> lower average cost in the hoeps that TCML members would want to purchase
> the excess.
> The board is 2" X 7.75" and the layout can be viewed at:
> http://teslaboys.com/SISG
> The boards have power traces on both top and bottom with 3 OZ copper in
> order to provide a high current rating.
> The heat sinks are quite large and give a 20 Deg C rise at 4 watts
> dissipation and 200 FPM air veocity - 38 Deg C rise at 8 watts and 400
> FPM - 42 Deg C rise at 12 watts and 600 FPM.
> We will need these special features to reach 460 BPS.
> The boards are designed to be set side by side with every other one
> reversed so that terminations are easy at each end of the boards.  A
> crude layout is available at the link above.  Each board would be rated
> at 3600 volts.  I put a via between each circuit so that if one needed
> to increment in less than multiples of (4) circuits it could be done.
> The boards will be done in a couple of weeks.  I do not have a confirmed
> ship date on the delivery on the IGBT's.
> If you would like to try these boards out let me know off list at my
> home e-mail teslamark@xxxxxxxxxxxxxx  Remember, this concept is not yet
> tested in fullscale yet.  I hope to be able to offer a board and the (4)
> 800 Amp IGBT's for $60(Note that the IGBT's are $23 in single qty from
> Digi-Key - but that price is a joke).  The rest of the board components
> are readily available from the typical distributors at reasonable cost.
> I have not provided all the technical details here for review but am
> working on that and will let you know when and where that is available.
> Thanks.
> Mark Dunn