Hey Guys,

I built an inverting amp with a LM324N (sorry, I forgot to make a scheme). I applied a +5v signal to V- and got back +5v at Vout. I'm guessing that you can't get a negative voltage with a positive supply? If this is the case, shouldn't I have gotten 0v? Do you have develop equations differently for single supply op amps as opposed to dual rail amps?

If you were wondering about the circuit, I have Vcc connected to 5v; GND is 0v. Feedback resistor (Rf) is across V- and Vout. I have +5v connected through R to V- and V+ is connected to GND.

Closed loop gain is 0.1.

 

Yes, an op amp can't generate a voltage different from its power supply.

The equations are the same.

And yes, the output should be at zero. What is the value of the resistors? Post your circuit diagram.

 

Yes, an op amp can't generate a voltage different from its power supply.

The equations are the same.

And yes, the output should be at zero. What is the value of the resistors? Post your circuit diagram.

Don't know the next time I'll be able to get back. I've got limited internet access right now, but my input resistor was 10k and the feedback resistor was 1k.

 

So the output should be near zero. Double-check all the pin connections on the op amp. Sounds like one or more are wrong.