- Joined Jun 16, 2016
I built myself a mains power monitor using current transformers. The voltage sensing is done via a 12ac/ac wall wort and a voltage divider. This is expensive, large, clunky, and inconvenient. Since I am just measuring voltage with minimal current draw (the divider is using resistors in the kilo ohm range) I figured I could use a transformer that has fewer turns of copper. The goal is to get a component that is $1 or less per piece for this job. Finding 10:1 or 20:1 windings in this range has been challenging. I can order ferrite toroids for cheapish, and could wind my own with low gauge copper wire, but if I did that, I'd like a little guidance on how many turns would be needed for the draw which would be in the low milliamp range.