Bob,
I will try my best:
The voltage drop over R2-1 (U=R*I) is amplified in U1 by a factor of 10. This factor is set by R1 and R2. The maximum current = 6A the resistance of R2-1 is 0.05R which gives 0.05 * 6 = 0.3 Volts. The output of U1 is 0.3 * 10 = 3 Volts. The reason for R2-2 is to raise...