RE: Measuring Current Spikes on Pole Transformer Primary side

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Terry Fritz" <teslalist-at-qwest-dot-net>

Hi,

One may also want to monitor the voltage with a high voltage probe (a 
standard probe would fry under such wild transient conditions).  If one 
really is hitting 10's of kAmps, the line voltage will get jerked all over 
the place.

Usually, the resistance of the wiring will dramatically damp such current 
spikes.  But if you can get the inductances kicking thousands of volts into 
things, the sky's the limit ;-))

Adding a heating element in series with things is usually a good idea since 
tearing up the AC line can do a lot of damage.  A spike now and then will 
not hurt things but if a coil send a barrage of AC line spikes around the 
house for say 10 minutes straight...

It would be interesting to see scope captures of these types of super 
current spikes.  That would help us protect against them.

Cheers,

         Terry


At 08:00 AM 4/7/2003 -0400, you wrote:

>The test set-up is extremely simple.  All you need is an oscilloscope and a
>Pearson current monitor.  Simply put the primary (240VAC side of pole
>transformer) and monitor with oscilloscope.  Use a storage scope to capture
>these high current transients.  You could also repeatedly capture the
>transient spikes on a regular oscilloscope if you trigger it properly, and
>with lots of luck!  If you don't have a storage oscilloscope, the Tektronix
>2430A digital oscilloscopes work well although have a bit of a small
>learning curve.  I have (3) 2430A oscilloscopes if you are interested in
>purchasing one.  $500.00 each in excellent condition (no probes or manuals
>though)  They are left over from my business.
>
>The Captain
>
>
>
>"Unless you use a scope across the input to see the "peak" power levels
>...... "
>
>Dr. R -
>
>Can you describe the EXACT test setup that was used to enable you to see the
>40-50 KVA spikes? What instrumentation was used, how was it connected, and
>what steps were taken to ensure that the test setup was not picking up RFI
>or EMI from the operating Tesla coil?
>
>Regards,
>Scott Hanson
>
>
>
>  > Original poster: "Dr. Resonance by way of Terry Fritz
><teslalist-at-qwest-dot-net>" <resonance-at-jvlnet-dot-com>
>  >
>  >
>  > If you are using a pole xmfr with external reactor you need to realize
>that
>  > the pole xmfr, on very short pulsed cycles, will draw as much as 50 kVA
>for
>  > very short current spikes.  These are not evident unless you use a
>storage
>  > scope connected across the primary side.  The short high power spikes
>occur
>  > just as the reactor tries to saturate.  A standard 10 kva pole xmfr may
>  > operate at short pulses of 40-50 kVA when used with a standard
>non-saturable
>  > reactor design.
>
>(snip)
>  >
>  >  > Dr. Resonance
>  >
>