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

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---------- Forwarded message ----------
Date: Tue, 12 Dec 2006 07:40:08 +0100
From: Finn Hammer <f-h@xxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: BIG SISG/OLBRISG - Re: Thanks from Terry (fwd)



Tesla list skrev:

> 
> :-)))))  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)))

It would be great if the PIRANHA PSU could be triggerable over a wide 
range of break rates, like say, 50-1500. Is that possible?


> 
> 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.

I am not even sure there is a 50ohm option in a TDS2xxx series scope.
> 
> 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" ;-))

Ok. I already noticed that to get readings that just remotely justify 
the observed behavior of the circuit, I have to twist the leads of the 
differential probes.
But now it strikes me, the brick is right below the primary, so a probe 
ground lead loop probably picks up a lot of false signal from the 
primary coil flux too.
Without realizing it, I have already been having a coil like that.
The brick is positioned so close to the primary because it is an OLTC, 
where every µH matters.
Next logical step is a 6 brick unit: 3MOT`s in delta = ~3000V + resonant 
charging => 6000V. I`l see to it, that the motor is off axis by then.


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

Well, the caps sure give the breakrate away, when making measurements 
without breakout.

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