Re: Dual MOT plans - PIRANHA

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Terrell Fritz <terrellfone@xxxxxxxxxxxxxxxxxxxxxxx>

Wow!!

There is nothing too special about the IGBTs other than they have a 
large die size.  The part number was mentioned "far and wide" about 
it being a "great IGBT" which probably got it bought up for 
commercial uses as a "fashionable" "known good part".  But prices 
seem to be much higher on a lot of things these days....  The high 
quantity price is a bit artificially high right now since the 
unleaded version costs more and the leaded versions got picked up on 
last time buys.  But the leaded version is still a full production 
part probably due to military.

Newark seems to have the best single quantity price.  Newark, Mouser, 
and DigiKey are becoming a reasonable alternatives to Rell.com now...

Cheers,

        Terry


At 12:10 AM 2/15/2007, you wrote:
> Original poster: "Barton B. Anderson" <bartb@xxxxxxxxxxxxxxxx>
>
> Something to note regarding the IGBT's, they've doubled in price (as 
> of a couple months ago, I haven't checked recently). Check the part 
> number (listed in Terry's info) for availability and price. It might 
> be necessary to find a substitute near the designed values.
>
> BTW, if anyone has found a substitute, please share the info.
>
> Take care,
> Bart
>
> Tesla list wrote:
>
> > Original poster: Terrell Fritz <terrellfone@xxxxxxxxxxxxxxxxxxxxxxx>
> >
> > Hi Dan,
> >
> > SISG's and PIRANHA class coils can run at any power level depending 
> > on the number of SISG sections used.  It is about 6 inches of arc 
> > multiplied by the number of sections minus the toroid radius.  So 
> > one of Mark's SISG boards would be fine for say an 18 inch arc 
> > coil.  You would need a small variac or one of  the solid state 
> > variac boards Dr. R. mentions for control.  The basics of the SISG are here:
> >
> > http://drsstc.com/~sisg/files/SISG.pdf
> >
> > I never got further on "my" solid state variac thing.  I "think" 
> > DC's needs a charging choke where mine would not.
> >
> > Most of the details are here:
> >
> > http://drsstc.com/~piranha/PIRANHA/PIRANHA-2/
> >
> > There are actually "three" versions of the PIRANHA.
> >
> > PIRANHA-I was the first demonstration coil:
> >
> > http://drsstc.com/~sisg/files/SISG-coil/P7150177.JPG
> >
> > http://drsstc.com/~sisg/files/SISG-coil/P7150179.JPG
> >
> > http://drsstc.com/~sisg/files/SISG-coil/P7150184.JPG
> >
> > http://drsstc.com/~sisg/files/SISG-coil/Scematic.gif
> >
> > http://drsstc.com/~sisg/files/SISG-coil/SmallSISG-2.gif
> >
> > It used a modified prototype 3 sections SISG experimental board:
> >
> > http://drsstc.com/~sisg/files/SISG-coil/SISG-Small.jpg
> >
> > http://drsstc.com/~sisg/files/SISG-coil/SmallSISGCoil.pdf
> >
> > It's a cool coil, but the giant resistor in it waists way too much 
> > power.  Although it demonstrated and served as a prototype of the 
> > concepts, the PIRANHA-I electrical design is really very obsolete 
> > and I don't recommend it.  The physical coil is fine.  If it was 
> > not for historical value, I would replace the electronics with PIRANHA-II
> >
> >
> > PIRANHA-II uses the full PIRANHA charging system for very high 
> > efficiency and is what you want to use:
> >
> > http://drsstc.com/~piranha/PIRANHA/PIRANHA-2/Complete-3.JPG
> >
> > http://drsstc.com/~piranha/PIRANHA/PIRANHA-2/
> >
> > http://drsstc.com/~piranha/PIRANHA/PIRANHA-SCH.gif
> >
> > http://drsstc.com/~piranha/PIRANHA/PIRANHA-2/PIRANHA-Const-006.JPG
> >
> > http://drsstc.com/~piranha/PIRANHA/PIRANHA.pdf
> >
> > http://drsstc.com/~piranha/PIRANHA/PIRANHA-Details.pdf
> >
> > You would just change it to use "one" of Mark's boards and it would 
> > use a lower input voltage and current.  All the component values 
> > are the same but the caps probably don't need very high current 
> > ratings for just one board.  With its ball terminal toroid (which 
> > works fine*) and PIRANHA-II electronics, it is probably one of the 
> > most advanced Tesla coils on Earth (although the vastly more 
> > complex DRSSTCs have more technology and "stuff", they don't work 
> > as well ;-)  Finn's triggered single brick BRISG is a "stunningly" 
> > wonderful machine too!!
> >
> > *Dave has made the biggest sparks off a ball terminal with his coil:
> >
> > http://hot-streamer.com/temp/DaveBaehr/b03_2862.jpg
> >
> >
> > PIRANHA-III is a dual MOT 120VAC 20 AMP (single circuit :p ) coil 
> > that would put out 8 foot arcs.  Although designed, it has not been 
> > built yet.  PIRANHA-II scares me bad enough at "1/2 power" already =:O)
> >
> >
> > Microwave parts can be bought new and at a great price from this 
> > place if you don't want to shop at the junk yard:
> >
> > http://www.amiparts.com/consumer/catalogindex.htm
> >
> > The higher wattage MOTs are best since they do not have as much 
> > loss and are fairly cheap at $55 to $65.  Those 16kV 750mA  AMI3347 
> > diodes RULE!!
> >
> >
> > Note that PIRANHA primary drive circuits are EXTREMELY dangerous!!!
> > There is "NO current limiting on the HV"!!  Ballasting is done by 
> > "magic"*.  Even pig systems are probably safer!!  PIRANHA-II's 
> > primary circuits are totally enclosed and double insulated.  It 
> > does not need cooling vents since it does not waist power.
> >
> > *I was hoping Conner would figure it out :O))  But only the 
> > computer seems to know...
> >
> > Cheers,
> >
> >         Terry
> >
> >
> > At 03:35 PM 2/12/2007, you wrote:
> >
> > > Original poster: "Daniel Kline" <daniel_kline@xxxxxxxxxxx>
> > >
> > > Hi Dr. R.
> > > I would like to request a set of the dual-MOT plans mentioned below.
> > > Would it be possible to run on one MOT for lowered output?
> > > Thanks,
> > > Dan K.
> > >
> > > Tesla list wrote:
> > >
> > > > Original poster: "resonance" <resonance@xxxxxxxxxxxx>
> > > > The best route for an experimenter than can live with 7.5 to 8 ft 
> > > > long sparks is our dual MOT design.  Matching dual MOTs can be 
> > > > obtained direct from AMPI.com for $100 each and the SISG boards 
> > > > are inexpensively available from Mark Dunn.  I give away the dual 
> > > > MOT plans on off-list request.  It's a great coil, highly 
> > > > portable, easy to set up, and most important --- I did the design 
> > > > so it would operate from two separate 120 VAC circuits, each 
> > > > circuit driving a single MOT at 16-18 Amps.  220 VAC not required 
> > > > for 7.5 to 8 ft long sparks.