Robocraze Voltage Transformer Module Active Single Phase Voltage AC output Sensor Module for boards compatible with Arduino (Pack of 1)

Although there are lots of writeups and videos in how to implement this module, I couldn't get it working. If you are looking for ac volt sensor which can be implement easier, I recommend pzem 004t instead even if it's costlier.

The voltage readings are usually not reliable.No matter what trim or settings you use !I tried matching the trim value to the actual voltage reading(using voltmeter): then it gave correct readings only for a while- after which 220 V suddenly became 150 volts