To balance my bridge, which of these would you recommend and why? I prefer the last of the three because I believe it would have the least effect, a 10Ω 21 turn pot is the smallest with the most turns I have been able to find and I will probably end up with middle example. My measurement show that the bridge is unbalanced by one leg having .1Ω more than the others, but my INA128 is multiplying it's effect by about 1000. Another idea I have is to parallel the pot in example 1 with a 1Ω resistor. I haven't tried it yet, do you think it would give finer adjustments?
If I stayed with the 14 volt excitation, I would end up with each half of the bridge developing 280 milliwatts of heat, it's recommended to stay under 100, so using 8 volts will yield 92 milliwatts of heat. Because I am trying to keep things working in the mid range of 14 volts, I plan to float the regulated 8 volts on a 2.4 v zener. Your advise and comments are very much appreciated.
Thank You,
Kinarfi