Ignoramus29580 wrote:
Let's say that I have a cable and I want to measure the AC current
going through it. Up to, say, 100 amps.

I could use a current transformer, right?

If I have a say 200:1 current transformer, then on a 100 amp AC
current it would want to produce a 0.5 amp current. Then if I stick,
say, a 1 ohm resistor across it, it would produce 0.5*1 = 0.5 volts
AC across the resistor.

Is that right?

Yes, assuming that you haven't exceeded the primary
or secondary current ratings for the transformer.

Furthermore, since you're probably looking to
use it on your tig welder inverter, the transformer
probably should be rated to be accurate for
pulse work rather than just 60hz sine waves.

Here's more than you want to know about CT's:

http://www.kappaelectricals.com/technical.html#current

Oh, and don't ever leave the secondary open with
a load in the primary....

Jim Stewart wrote:

Yes, assuming that you haven't exceeded the primary
or secondary current ratings for the transformer.

Wouldn't a hall sensor do a better job?
I mean with all the square wave and changing frequency a current
transformer seems to be not the best choice.
And if he is in DC ...


Nick, just curious
--
Motor Modelle // Engine Models
http://www.motor-manufaktur.de
DIY-DRO - YADRO - Eigenbau-Digitalanzeige

Nick Müller wrote:
Jim Stewart wrote:


Yes, assuming that you haven't exceeded the primary
or secondary current ratings for the transformer.


Wouldn't a hall sensor do a better job?
I mean with all the square wave and changing frequency a current
transformer seems to be not the best choice.
And if he is in DC ...

Well, since it is Iggy that posted the question,
he probably has a big bag of surplus CT's that
he bought for $.50 (: