xmat said:
The DC level needs to be estimated for the ( t1,t2 ) period..Got it?
Yes, I think we got it first time.
The output of the integrator WILL vary during the integration period.
At the end of the period, the output voltage will represent the area under your curve.
RonH has shown the way to start and stop the integrator with S1 in his simulation. S2 resets the integrator ready for the next measurement.
Use FET switches for S1 and S2, add a bit of logic to start and stop when you want, and select the R and C in the integrator to give you the appropriate scaling.
JimB