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On Thu, 16 Feb 2006 21:35:15 -0800, "RST Engineering"
<jim@rstengineering.com> wrote:
>Yes, rather trivially.
>
>Jim
>
>"ccwillwerth" <ccwfbc@bellsouth.net> wrote in message
>news:CcaJf.17927$Ly6.4626@bignews5.bellsouth.net...
>> How is a shunt determined for a digital volt meter to determine amp? Can
>> a voltmeter that is using the measured voltage for its own power be set up
>> on a shunt to measure amps?
>>
>> Charlie
>>
I disagree with Jim here; most calibrated shunts that one would
purchase are either 50mV or 100mV at full load, and 0V at no load. I
do not know of any meter that relies on measured variable for its power
which will work with zero input. That is sorta sarcastic; I also know
of none that will work with 100mV, full scale on a higher than common
shunt.
As for the determination, Jim is 100% correct; you would want a
voltmeter with a very low input range, 50 or 100mV. Assuming oyu
wanted 50mV to correspond to 50A, using Ohms law, R=E/I you get
0.001=0.05/50 so you want a 1 milliohm shunt. You have #10 wire? It
is about 1 Ohm/1000ft, or 1 milliohm/ft. Stick 2 pins through the
insulation about a foot apart and hook them to the meter.
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Re: Volt / Ammeter
