Hi guys,
I have got a question.
I have an altenate wave going to an inverting op amp for amplification by factor of say 30. Now I need to Sum the said alternating signal by some amount of DC offset. Suppose that the alternating signal is "Vm*sinwt, so I want to get "Vdc + Vm*sinwt" at the output of the op-amp. I know that I can use a second op-amp as a SUMMING op-amp so that add the dc offset which is generated by a pot? But Do I HAVE TO use the second op-amp as the summing op-amp? IS'nt it right If a mix the pot to the first op-amp somehow to get
"Vdc + Vm*sinwt"? It will help to avoide using a second op-amp as summing, But I am not sure if it is effective just like using the second op-amp? Of course I am able to add a second op-amp as the summing if there is any problem with the other method I am taliking about.
I myself thinking of using just the said inverting op-amp and use its noninverting pin to add the said dc offset. Any idea plz?
Thanks in advance