Re: Current sensing

[darrylmcmahon igs net]

> I must be missing the design theory for large current measure, because it
> has to be cheaper and easier than things like....
As suggested in other posts, a purpose designed shunt will work 
best.  If you want to save some money, you could use one of the 
power cables already on board as your shunt.  If you know what 
gauge the wire is, there are tables of resistance for each American 
Wire Gauge (AWG) size.  Based on that, you can determine the 
length of wire to give the desired resistance for the full deflection 
panel action.  Let me know if you want more details.

The advantage is that you are not dissipating any additional power, 
you need the power leads anyway.  I built a couple of these years 
ago, and they were accurate within 10% when tested against a 
professional, calibrated meter (and the Radio Shack millivolt-meter 
was only rated as being within 10%).

Darryl McMahon             48 Tarquin Crescent,
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