Op-Amp Servo loops on bread board

[Rajesh jabade]

Hello All,
I am trying to rig up Op-Amp servo loop circuit on bread board. Please let me know if anyone has tried it earlier.

Thanks
--Regards
RJ

 

[crutschow]

Of course others have done that. So what's your problem/question?

 

[Rajesh jabade]

crutschow,
Thanks for the reply. When I tried to measure offset voltage, my Aux op-amp is saturating. Can you please share any circuit which i can try on bread board. Any link which will give me detailed idea.

--Regards
RJ

 

[:Dark_Force]

Maybe you should first tell us what your servo circuit will be used for, what are the voltages and so on. Or at least post a schematic of the actual setup.

 

[Rajesh jabade]

Hello,
I have attached my schematic

https://obrazki.elektroda.pl/3738457400_1409655343.jpg

https://obrazki.elektroda.pl/3738457400_1409655343.jpg

I am trying to simulate it it in LTSpice too.

Thanks
RJ

 

[crutschow]

What is U5 supposed to do? You have the inputs connected with two 100 ohm resistors and no feedback so the output will saturate just due to the input offset being amplified by the open-loop op amp gain.

The second stage is an integrator with no reset circuit so that will also go to saturation due to input bias current.

So what is the complete circuit supposed to do?