Hi All,
New Arduino (Mega) user here.
I have a requirement to measure AC with varying amplitude up to a maximum of 100v but typically around 20v. The current is limited so safety isolation is not required.
I went with the common zmpt101b and have ran into a problem. At low voltage (haven't converted it yet but probably around the 10v mark) the readings show a type of resonance or similar making them unusable (see screen-shot).
Thinking about how to resolve it, I could either change the transformer or use the full-bridge method. The later induces a voltage drop of about 1.2v which isn't great for low value reads but perhaps I can offset it for reasonable accuracy. This accuracy may be no worse anyhow than the transformer approach.
Whatever approach I end up it must have minimal (ideally none) phase shift. The same source is regulated using GND so approach must be isolated or rectified (can't have one line attached to GND).
Just seeing what people think, recommendations etc!
