11 Gauge Wire...where?

[Lloyd Burns]

The furniture indusry uses 11-ga hardenable wire to make sinusoid zig-zag springs. Some of the bending machine manufacturers list the automotive industry as buyers of the products of their machines. The other size in common use appears to be 8-1/2 ga. :-)

As to current shunts, make a shunt which is longer than you need, calibrate (use an ammeter to show the current), measuring the voltage between two points on the shunt, attaching take-off wires at the points. I used this to measure motor current with a voltmeter, at 10 A = 100 mV.

Alternately, use something close to your shunt design, and send the signal through an op-amp: send a known current through the shunt, and adjust the output to make it give the size of output you want, for example 20 mV/A. With an op-amp, you can even set the zero to 2.5V, or 127 on an analog input, by adjusting the offsset (bias), even measuring a signal not far from ground.