On Jan 1, 8:19*pm, wrote:
As part of another project, would like to take some High Current DC measurements.

I have a couple of multimeters ... but obviously not going to be any good for around 80-100A

Now going back to school physics lessons I could use a Shunt resistor ...http://www.societyofrobots.com/robot...?topic=13900.0

The issue will be obtaining a suitable shunt ... assuming I use a 1 ohm shunt, anybody made one of these ?
The WEB ref page:http://www3.zetatalk.com/docs/Electr...Made_Shunt_for...
details using 12guage copper wire .. based on 1.619 ohm per 1000'

Although maybe a resistance wire may be better *eg Nichrome around 10.58" for 1 ohm.
Welcome to any better ideas.

Using copper wire for a shunt is fine if the temperature does not vary
much. The link
you posted overcomplicates things a bit.
1) You don't need to worry about the resistance of the meter if you
use a voltmeter
and calculate the current.
2) You can calibrate the shunt by first using a long length of wire
and passing a current that
one of your existing meters can measure. Then shorten the wire and
scale the
readings proportionately.

Make sure you use 4-terminal measurements. In other words, pass the
high current through
the sensing wire and add a pair of connections soldered onto that
wire, one near each end.
The millivoltmeter is connected to those soldered tappings.

John