Re: Cost of Silicon for DRSSTCs

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Steve Ward <steve.ward@xxxxxxxxx>

Hi Steve,

I will speak of my own experiences here.  IGBTs can be had for free if
you can get samples from the company that makes them.  This is where i
obtained my "smaller" IGBTs that i use for spark output up to 6 feet.
The IGBTs here were the HGT1N40N60A4D.  Spec sheet here:

http://www.fairchildsemi.com/ds/HG/HGT1N40N60A4D.pdf

Also look at the HGT1N30N60A4D, i think i saw newark (maybe somewhere
else) was selling them for $13 or so, each, not too bad.  You can also
find these IGBTs on ebay often.

On my larger coil (up to 11 foot output) im using the CM300DY-24H IGBT
modules made by powerex (mitsubishi).  Data sheet can be downloaded
here:

http://www.datasheetcatalog.com/datasheets_pdf/C/M/3/0/CM300DY-24H.shtml

I purchased mine on ebay.  When IGBTs first started hitting the ebay
market, there was really a surplus of them and they sold for dirt
cheap (i got my first batch of them for 5 bucks a pop!).  Now you can
rarely find them for about 45 bucks each (after shipping).  CTR
surplus is one seller i know of that seems to have them the most.
They used to have a lot of auctions with "buy it now" for $36 with $9
shipping.  I use a pair of these IGBTs for my setup.

Other people have been using international rectifier parts (Terry
Fritz is using an IGBT from them that i think costs $6-7 each).  I
think he gets them from digikey.

If you are really interested in DRSSTCs, you are gonna have to do some
searching for yourself.  I know of my sources for parts (mentioned
above) but there may be other (maybe better) ways to find these parts.
 Ebay is always a good place to look.  Learning a bit about IGBTs
helps you decide what IGBTs will work and what ones wont, so you can
decide if any of the ebay auctions have IGBTs that work for your
project.  Switching speed is crucial, but so is rated current and
voltage.  Watch the gate charge.  Its really not just as simple as
looking at the voltage and current ratings, there are many other
things to consider, so knowledge about IGBTs really helps.

Steve Ward



On 5/8/05, Tesla list <tesla@xxxxxxxxxx> wrote:
> Original poster: "S&JY" <youngsters@xxxxxxxxxxxxxxx>
>
> I would appreciate someone giving us a rough idea of the cost of IGBTs per
> foot of streamer length.  Better yet would be to add representative IGBT
> part numbers along with the costs.  The idea is to give those of us who may
> venture into the world of DRSSTCs an idea of how big a bankroll one would
> need.  Seems like Greg Leyh was talking in terms of 6 figures for his twin
> monster.  But I am more interested in how long a streamer can be achieved
> with $50, $100, $200, $400, etc. worth of IGBTs.  Also, what are the good
> sources for them?
> Thanks,
> --Steve Y.
>
>