Units back in stock. Hold relased.
The op-amps I was using on the prototype all worked 100% replacing the 20 TI parts on the build of the first 10 units. I may have just got a bad lot of TI parts but now I don't think I will ever use those TI parts again.
Anyway, I kept the calculated current values because testing the lot of 10 units proved the accuracy was very good.
Here is the recorded current results of those first 10 units. I measured three currents, the 4 amp minimum current for fan fail flash, the 18 amp maximum current for fan fail flash and the 20 amps "fuse" trip current.
#1 pin 85 = 4.1, 18.1, 20.2
pin 86 = 4.1, 18.2, 20.1
#2 pin 85 = 4.1, 18.3, 20.4
pin 86 = 4.1, 18.1, 19.8
#3 pin 85 = 3.9, 17.9, 20.0
pin 86 = 3.9, 18.1, ??.?
#4 pin 85 = 4.0, 17.9, 19.9
pin 86 = 4.0, 18.1, 20.1
#5 pin 85 = 4.2, 18.2, 20.4
pin 86 = 4.0, 18.0, 19.9
#6 pin 85 = 4.1, 18.3, 20.4
pin 86 = 4.1, 18.2, 20.2
#7 pin 85 = 4.1, 18.1, 20.2
pin 86 = 4.2, 18.5, 20.4
#8 pin 85 = 3.9, 18.0, 20.1
pin 86 = 4.1, 18.3, 20.3
#9 pin 85 = 3.9, 18.0, 20.0
pin 86 = 3.9, 17.9, 19.8
#10 pin 85 = 4.0, 18.1, 20.1
pin 86 = 4.1, 18.2, 20.1
Voltage drop over each leg at 15 amps is 0.050 volts. Very little change in voltage drop after running the double 15 amp loads for 30 min. The current sensing value did not change at all after the 30 min. run.