[Prev][Next][Index][Thread]

Re: status report, questions, etc.



You wrote: 

>question:
>
>How does one use and calibrate a current transformer?  More 
specifically, 
>I know that you put one of the output (220V) leads through the hole, 
and 
>then connect an ammeter across the output leads, but why would the 
current
>be limited?  I thought non-current-limiting transformers would produce 
as
>much current as the load can draw.  Since ammeters are low in resistance,
>wouldn't this short out the meter?  Also, since there are 400 turns in the
>current transformer, would I get a 400:1 transformation in voltage?  This 
would
>be 88kV.  Also, how would I calibrate the current transformer?  Should I 
>just use ohms law and a big resistor or a few light bulbs?
>

Current transformers are designed to work into a load called a "burden 
resistor".  You can calibrate your transformer by using a known load (or 
another ammeter) and adjusting the burden R.

Zap,
Mark