QVAR Sensor - LSM6DSV16X - AC Wire Detection

[marshouse]

Is it possible to check the electrical activity of an AC power cable using Qvar functionality, as discussed in ST Note AN5755? The use case is to determine whether the cable is powered or not by keeping Qvar sensor electrodes close to the power cable outer insulation (noninvasively).

What type of electrode to be used? What type of input circuitry needs to be designed (input impedance and filtering)?

https://www.st.com/resource/en/application_note/an5755-qvar-sensing-channel--stmicroelectronics.pdf

https://www.st.com/en/mems-and-sensors/lsm6dsv16x.html 

[henrywill12]

Yes, it's possible to detect electrical activity in an AC power cable noninvasively using Qvar functionality as described in ST's AN5755. The Qvar sensor can sense electrostatic charge variations when electrodes are placed near the cable's outer insulation. The electrodes, typically made of conductive material, should be placed close but not touching the cable.

For the input circuitry, high impedance (megaohms range) is required to prevent signal interference, along with filtering to eliminate noise, focusing on the AC signal's frequency (50/60 Hz)

[marshouse]

This is what I had in mind so far:

CTRL7 (16h) as configuration for the input impedance. What is the criteria for selecting the electrodes? A floating copper foil connected to each input works? Is there any criteria for dimensions of the foil that matters for this use-case?

Any suggestions are appreciated.