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

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  • On the other hand, wouldn't the previous case imply that I am scaling down twice? So this might be correct instead:

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  • 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

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Which circuit is right?

  • 1
    \$\begingroup\$ The right circuit is the one that suits the ADC and the sensor. Data sheet links required. \$\endgroup\$ – Andy aka Aug 24 '20 at 15:04

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