From HwB

Cir OpAmpInvMany2.png

VOUT= -(V1/R1+V2/R2)*RO

This circuit is used to add several signals to one. By setting all resistors to the same value, R1=R2=RO, you get the following formula:

VOUT= -(V1+V2)

You can theoretically add how many signals you like. Here's an example with three in-signals:

Cir OpAmpInvMany.png

VOUT= -(V1/R1+V2/R2+V3/R3)*RO

Contributions

Sources

  •  ?
Retrieved from "http://www.hardwarebook.info/index.php?title=Operation_Amplifier:_Addition&oldid=3887"