RE: 18,000. AMP high energy Cap bank

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Tom Luttrell PWRCOM" <tom@xxxxxxxxxxxxx>

Just to expand on the current limiting topic a bit further...

If you charge the cap up to say 50kV and it has an ESR (equivalent
series resistance) of about 1 Ohm and you want to limit the short
circuit current to 20kA you will require an extra 1.5 Ohms in series
with the capacitor.

It's peak power handling looks huge (1 GW) but in low duty cycle pulse
situations this can be considerably lees. Using a series/parallel
combination of lots of 2W low inductance resistors you can usually get
away with just observing that the resistors peak voltage rating is not
exceeded. Trial an error can be expensive but explosively  fun.

>
> We use an Ion Physics Corporation CM-1-L current transformer
> (0.1V/A into 50R) to measure up to 50kA. We've also go a
> 100kA version somewhere but I couldn't find it to get the part number.
>
> The source impedance will control the short circuit current.
>
> > -----Original Message-----
> > From: Tesla list [mailto:tesla@xxxxxxxxxx]
> > Sent: Friday, 17 December 2004 2:00 PM
> > To: tesla@xxxxxxxxxx
> > Subject: Re: 18,000. AMP high energy Cap bank
> >
> > Original poster: FIFTYGUY@xxxxxxx
> >
> > In a message dated 12/11/04 9:46:06 PM Eastern Standard Time,
> > tesla@xxxxxxxxxx writes:
> > The capacitors weigh about 100 lbs each.  Caster
> > oil fill caps.  Rated 18,000. AMP High Energy pulse capacitors.   3
> > capacitors in parallel is 54,000. AMPS.
> >
> >      How does one measure these very high current levels to
> any degree
> > of accuracy?
> >      How does one limit these current levels? If a energy discharge
> > cap system has an ultimate safe rating of (say) 20kA, how does one
> > make sure that current isn't exceeded during an experiment that
> > vaporizes a specimen?
> >
> > -Phil LaBudde
> >
> >
> >
> >
> >