"Tim Wescott" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Problem: I need to measure up to 30 amps (50 would be nice), I've spent
> my discretionary budget for the upcoming month, and all I have are 10A
> meters.
>
> What's a good quick & dirty current shunt? There's no dead heaters on
> site -- would it make sense to hack a bit of FR-4 to just the right
> length & width to develop 50mV at 50A (while dissipating 2.5W, of
> course)? Or should I find the right length of copper wire to do this?
If these meters have an internal 10A 50 mV shunt (probably a piece of #14
Manganin wire), just cut it in half and put the pieces in parallel. That
will give you about 40 amps at 50 mV, although it might overheat if you run
it too long at 40 amps. It should handle 25-30 amps without too much
problem, especially if you allow some air cooling. Copper wire is OK if the
temperature does not change, or if you adjust for the tempco.
Paul
|
Similar Threads
Linear Mode
