Re: 18,000. AMP high energy Cap bank

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Dr. Resonance" <resonance@xxxxxxxxxx>


It's also a good idea to set your coil up to fire one pulse every 10 sec,
and there are 2 ways to do this:

Precision firing:  Rectify the HV off the pwr xmfr to DC and fire thru an
ignitron such as a National 7703 (Richardson Electronics -- $1,100.

Non precision firing:  Rectify the HV off the pwr xmfr to DC with a long
string of diodes (we use Fuji) and then run thru a 10 meg (bunch of cheap
series resistors) resistor which will provide a shot every 8-10 sec
depending on resistor value.

With a Pearson or Ion Physics current xmfr you can see the current waveform
and get a precise measurement with an "antenna" pickup on the scope (6-8
inches of bare wire then into coax line).  Place antenna 6-12 feet away
depending on size of coil.  You want enough distance to get a clear signal
without swamping the scope.

Since the potential measured in this single shot mode is independant of the
waveform, you can use a 6-12 inch sphere near the toroid and measure the
precise coil voltage from the single shot sparking distance.  Use Handbook
of Physics & Chemistry for the tables.  Use a ground sphere that matches
your toroid's minor dia.  It's always interesting to compare these results
with the calculated Vsec = Vpri * X * SQR (Ls/Lp).  Solve for X, the
efficiency factor, to see the efficiency of your coil.  It's usually 50-75%
for the X value.

You can also place a 50 Ohm resistor near the antenna-coax junction to
change the peak current into peak voltage and calibrate you scope for
potential measurements.  You need a 100 kV DC power supply to attach to the
coil's toroid for calibration, and then it's a matter of potential indicated
vs. distance for the peak potential.

Dr. Resonance


>
> 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 soucre impedance will control the short circuit current.
>

>  > 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?