Hello all :

Could you help me check the SCH as follow, I just want to make

Vouput=Vinput, but I'm not sure whether it is OK. Thank you.

 

I don't think you've got the summing integrator stage U1-A right.

One would normally add the input and feedback signals via equal resistors into the -ve input terminal. Then tie the +ve terminal to ground. Provided the total control loop feedback signal polarity is correct [trace it around the loop] then OK. I'd add a small resistance in the U1-A feedback path to give a P+I control rather than pure I control.

You would also need to check the overall stability in closed loop so that you don't get unwanted self oscillation.

 

Also to get Vo=Vin you would need an inverter stage in the feedback path - otherwise the magnitudes match but the sign is inverted. If you did this you would have change U1-B to an inverting stage to keep the relative input/output sign sense (phase?) around the closed loop correct.

 

This is what I mean.....

 

Thank you very much, t n k, I will make test for it. thank you.

 

Also to get Vo=Vin you would need an inverter stage in the feedback path - otherwise the magnitudes match but the sign is inverted. If you did this you would have change U1-B to an inverting stage to keep the relative input/output sign sense (phase?) around the closed loop correct.

I don't see anything wrong with the phase of the feedback. It's basically just a big voltage follower. Loop stability might be an issue.

EDIT: The simulated circuit was stable. The .ASC file for LTspice is attached.

 

Steven, why did you make it so complex? A voltage follower doesn't need two op amps, or an integrator in the feedback loop

 

Agree with Ron supped up voltage follower

 

Use an op amp with the input signal at its non inverting input and the feedback taken from the output (load) and connected on its inverting input.