ADWSystems
Member
I have a sensor to which I need two outputs, Sensor*10 + 0.5 and Sensor*10 + 0.2. I applied the gain in the first stage and then add the 0.5 and 0.2 in a second stage.
My initial thought is below:
![Opamp Dual Adder.jpg Opamp Dual Adder.jpg](https://www.electro-tech-online.com/data/attachments/56/56672-682ff5e05e4ef4a801da11c036cf1dca.jpg)
By just looking at it I see a whopper resistor network. Resistors R1, R2, R7, R8, R9, R12, R13, and R14 are all tied together. I have isolated the pot for tuning the 0.2V and 0.5V source using a voltage follower, but I'm wondering if I also need to isolate the output of U1 from R8 and R13.
My initial thought is below:
![Opamp Dual Adder.jpg Opamp Dual Adder.jpg](https://www.electro-tech-online.com/data/attachments/56/56672-682ff5e05e4ef4a801da11c036cf1dca.jpg)
By just looking at it I see a whopper resistor network. Resistors R1, R2, R7, R8, R9, R12, R13, and R14 are all tied together. I have isolated the pot for tuning the 0.2V and 0.5V source using a voltage follower, but I'm wondering if I also need to isolate the output of U1 from R8 and R13.