Unity Gain op amp circuit?

[jetbat]

Hi, I was wondering if this op amp is running at unity gain? I know with just the two 22k resistors it is. But with 3, I don't know. Anyone have some insight?

Thanks
Scott

 

[kaos]

It’s an inverting summing amp with two inputs (it basically adds the two signals together and inverts). For inputs of +1V & +1V you get –2V at the output. For inputs of +1V,-1V you get 0V at the output, +1V & 0V = -1V, and so forth.

 

[AndrewT]

Yes, it's a unity gain opamp.

The gain at each input is set by the feedback resistor divided by the input resistor.
In both the inputs, the gain is 22/22 = 1

As Kaos has said, the opamp ADDs all the input signals. You can put on as many as you like

 

[jetbat]

Thanks, I understand now.