I'm going to use a RS485 modbus connection which requires a twisted pair. Now I also need power, that will be a 5V line and a ground. The distance will be about 3 meters max. Can i use a twisted pair for the 5V and gnd as well? Or will that result in a voltage drop?
There are a couple things to take note of to know if this will work:
- Peak current draw of your load: $$I_p$$
- The acceptable voltage drop your load can accept: $$V_d$$
- The resistance of your cable: $$R_C$$
$$I_p \times R_c \leq V_d$$
Then you're good to go.