Hi,
In this video, at 1:30...
....it shows a device which has no batteries, but which gets all its operating power from the mains. It does this with a simple CT which clips round the mains line which enters the house. The same CT measures the mains current which leaves/enters the house.
What would you say is the best type of material for this CT? Surely it would best be iron? However, powdered-iron would be used as it would be cheaper to make “split ring”?
Also, I would have thought the having the current measurement function, and energy harvesting function, coming from the same CT, was somewhat of a compromise?
Would you agree it would be better if there were two secondaries, one for current measurement, and one for the harvesting? The harvesting one would pretty much be a full wave diode bridge into a big-gish capacitor? …and with a wee SMPS to give a known voltage output, and a clamping Zener in there for those occasions when the capacitor might otherwise get overvoltaged?
None of the web docs say much of the powdered iron material used....