BIG SISG/OLBRISG - Re: Thanks from Terry (fwd)

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---------- Forwarded message ----------
Date: Mon, 11 Dec 2006 15:57:33 -0700
From: Terrell Fritz <terrellfone@xxxxxxxxxxxxxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: BIG SISG/OLBRISG - Re: Thanks from Terry (fwd)


>Hi Finn,
>
>   Hopefully the new trigger will be able to fire to
> > 100MVA and still be simpler than Finn's :-))
>
>Well that should be easy. With just a SCR and a trigger transformer per
>stage, take your pick!. :-)

I am thinking of using maybe two auto ignition coil connected to both ends 
(or maybe inside the strings) of the SISG.  They would shock or stun the 
SIDACs into conduction while providing isolation and all.  It would be very 
simple and just an add-on for present SISG non-trigger systems.  But I have 
not done any testing yet.


>At present, the OLBRISG coil is running V.2 SISG trigger board, and
>producing 48 inches/120cm ground strikes with one single CM600 running
>4kA peak.

:-)))))  I am thinking we need to put about "40" CM600 in series :-))  At 
4000A peak that is 160 MVA >:-))  If you can get 48 inches out of "one" 
then 40 might do 160 feet!!!  The bricks can be paralleled too if they do 
start to get slightly warm... :-))))  The SIDAC parallel resistors probably 
need to go to a lower value in long strings...  The PIRANHA configuration 
should work fine with a 100KVA 33kV pad transformer...  Most are three 
phase so they could run like three coils :o)))


>At these currents it gets tricky to measure stuff. There are a
>couple of volts/centimeter, even in wide conductors.
>I`m out of range on the scope with a Pearson 101 and 500A/division. Well
>I guess I could halve the sensitivity by terminating to 50ohms. I think
>the bricks are good for more current, they don`t get hot at all.

If they don't get hot "yet", maybe 20,000 amps >:o))  I am not sure anyone 
has ever blown one up due to a pure high current pulse?

The 50 ohm termination will drop the voltage in half.  I use a "T" BNC 
adapter and a BNC 50 ohm termination rather than the 50 ohm thing in the 
scope.  I think it is safer for the scope that way.

You could probably just put the CT "near" the primary too.  It might pick 
up enough current unconnected to give a good reading with just a little 
calibration.  I was always going to have just a little loop of wire "near" 
the primary to act as a simple CT too.  At 4000 amps, you really can't miss 
the current and there wont be much "interference" ;-))

Magneto-constriction might start to be an issue at these currents too.

Cheers,

         Terry



>Cheers, Finn Hammer
>Scopin` and hopin` in Denmark