Yesterday I decided I needed to amplify a ~20mv DC signal to 5v so I looked around the net and found that an operational amplifier is the best route. I found some sample schematics and decided to give it a shot. Since I didn't have any I went to ratshack to discover they only have one type and it's the old 741 (I despise that store). I spent about an hour trying to get the thing to work until I realized that it requires a negative voltage source, I just assumed ground was equivalent. This really hinders my simple circuit. Are there alternatives to this? FYI I am amplifying a binary signal to a 5v square wave so it's really nice how the op amp will trim the edges so to speak when it hits the 5v ceiling due to the 5v V+. I *sort* of have it working with the 741 but it's really not how I want it at all. I can't stand the idea of having to get this thing a negative voltage when it shouldn't ever need it. Also for some reason the output is defaulting to 5v with the way I have it now, and only dropping during input fluctuations that go from high to low. It's really strange. I can ground the input, give +5 to the input, and the output stays at +5. Or I can give -5 to the input and then it finally drops. So needless to say none of this is how I want this to work. Anyone have any suggestions on what I should do? Maybe a more modern op amp to try, or even a completely different approach? I'd really appreciate any help.
Thanks a lot
Thanks a lot