I have a sensor with an output between (-10 V, +10 V) and three analog out cables: Sensor(+), Sensor(-) and Sensor(GND). I want to scale down the signal to (-2 V, +2 V) and feed it into an ADC. I understand how to implement a voltage divider when scaling a positive voltage signal with two cables (Vin and GND). However I am not sure how to do it in this case with three cables.
- On the one hand I imagine it should be possible to scale-down each end individually and probe them with the ADC
- On the other hand, wouldn't the previous case imply that I am scaling down twice? So this might be correct instead:
- However the 2nd circuit would not be measuring the voltage difference between +V and -V, while this one would. However the GND cable is not being used at all
Which circuit is right?