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Re: status report, questions, etc.

In a message dated 95-11-16 02:17:10 EST, tesla-at-grendel.objinc-dot-com writes:

>Most (not all) CT's I've seen have the ratio somewhere on the unit.  If 
>that's the case, you really shouldn't have to "calibrate" anything.  The 
>transformation ratio is simply the current in to current out ratio (ex. - a 
>200:1 CT that you're running 50A through would give you 50A/200 = 
>250mA short-circuit current between the CT output terminals).  In this 
>example, you would use a 250mA full-scale AC ammeter to monitor up 
>to 50A.  You would then "calibrate" your ammeter by simply multiplying 
>the values on the faceplate by 200.  I imagine that you could put a 
>known resistive load across the CT terminals to monitor the current 
>indirectly from the voltage (V=IR),  but just using an ammeter would be 
>simpler and more direct (COMMENTS from anyone welcome?).
><<<
>I'm not trying to argue, just to understand...
>The CT has 400 turns, which would, I assume, give a 400:1 ratio.
>Why don't I just get a run away current if I use an ammeter?  What's
limiting
>the current?  Mark Barton suggests a burden load, which makes sense as an
>answer to me.  I'll try things out, but I hope to understand things a little
>better, so the I can keep the smoke inside the meter. :-)
>
>Chip

Chip,

The above description is correct.  A current transformer is made to be
connected directly to an AC ampmeter.  I bought a surplus current transformer
and a surplus amp meter and then relabled the scale on the meter so it would
read correctly.

BTW, 50" of spark from a 4" coil is great.  What is your input, 12kv at
120ma?  If so, you are getting the same performance at that power level that
I got from my 6" coil - or better!

Ed Sonderman