Hi everyone

I have circuit, giving out two measurement voltages. One ranges from 0-5V, the other one from 0-200mV. I need to transmit these two voltages over only 3 cables, so i want to create two voltage levels: v1 = 0-5V and v2 = v1+(0 - 200mV). At the other end of the line I get the v1 referenced to ground and the second voltage as a differential (v2 -v1).
First Idea was to use a voltage-adder opamp circuit, but the problem is, that the second voltage (0-200mv) is floating and not referenced to ground. So how can i add these two voltages?

Thanks in advance

 

Voltages are relative. The only way to work with separate voltages is to make them common at some point. Does anything prevent you tying the floating voltage to the 5 volt ground?

 

I think the solution just came to me. I actually CAN reference the floating voltage to ground, by shifting a few components around.
Thanks for starting me off