Yesterday I was disappointed to learn there is no magical IC to measure current flow in a standard appliance cord.
On the advice I received, I went ahead with a US5881 Hall effect sensor and split the conductors. I then passed only one of the conductors over the over the sensor (to avoid cancellation of the magnetic field from having two conductors in close proximity).
I wired it up as shown below. The setup works fine when tested manually with a permanent magnet. But I cannot detect any pulses when attempting to measure against the AC line. I do not have an oscilloscope, so pulses are being measured using interrupts on a digital Arduino input.
(I also tried with a 100nF capacitor on the source voltage and a 4.7nF capacitor on the signal legs, as shown on the datasheet. The result was the same: no pulses when measuring the AC current.)
Is this just a matter of insufficient sensitivity on the US5881? From the other thread I linked, I kind of got the impression this chip could measure AC fields with this setup, but maybe not? Or is there something wrong with my approach?