Re: OLTC Update

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

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

Hi Eddie,

I guess I really don't need to measure the current for any great reason.
The physics of the thing really defines what it "has" to be.  My only
concern was to verify the IGBT current sharing and that of the three loops.

I just punted and borrowed a probe to check the IGBT current sharing
(buried in the bottom of my desk at work...).  The current sharing is
perfect. ;-))  I think I can find a big clamp probe for the loops too this
afternoon.  So not a big deal really, once the currents are verified, it is
just a done deal.

One nice thing about these coils is that the voltages are low enough that
just any standard scope type scope probes work on it.  That really really
helps things ;-))

Cheers,

	Terry


At 12:41 AM 8/19/2002 -0600, you wrote:
>At 08:50 PM 8/18/02 -0600, you wrote:
>>Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>
>
>>I could kick myself for one thing...  I have no way of getting a current
>>monitor in the primary circuit :-((  I have like six Pearson current
>>monitors here (one is a 50,000 amp!) and no way to insert one in the
>>circuit.  I guest that is why they make the split clamp one types too (and
>>charge 5X for them!  They know when they gotcha!)
>>  
>
>Perhaps you could wind a Rogowski coil around a piece of hose or something
>similar. Use your favorite opamp to make an integrator. You could calibrate
>it against one of your Pearson transformers.
>
>some links that turned up on google:
>http://homepage.ntlworld-dot-com/rocoil/Pr9.pdf
>http://www.rocoil.cwc-dot-net/
>
>Eddie Burwell
>
>
>