OP Amp Math

[ADWSystems]

I remember and found the circuits for multiply (gain) and adding and subtracting. What I've been looking for (but not found) is to add and subtract in the same opamp. I would like to implement the equation (Vin1-Vin2)*10. Any links or circuits would be great.

 

[ericgibbs]

I remember and found the circuits for multiply (gain) and adding and subtracting. What I've been looking for (but not found) is to add and subtract in the same opamp. I would like to implement the equation (Vin1-Vin2)*10. Any links or circuits would be great.

him
This link shows a difference OPA

**broken link removed**

Googled: opa subtracter circuit

 

[ADWSystems]

I didn't google those exact words. So didn't get your webpage. The links I found and literature I have left off the key sentance and equation and the end of the first section. That's exactly what I was looking for. (I knew I was close, but couldn't quite remember all the rules/math, especially to deal with R2 and R4).