I was trying to use a torroid core with a slot cut in it and a hall effect device placed in the slot to detect the current through a wire. (Image 1 & 2) I used a A3144 (On-Off) and an Honeywell SS495A (ratiometric). With the A3144, with the current one way, it would turn on and stay on, I had to reverse the current to get it to turn off, with the SS495A, it started with one voltage reading, I would add current, and remove it and then have a different voltage reading, add and remove current again and the reading would change some more. It finally dawned on me that the torroid core was magnetizing. My next attempt at a solution was to use a ferrite core induction (#3) and things worked like I thought they should, the A3144 turned on and off at about the same current level each time and the output of the SS495A returned to it's static level after current was applied and remove. I haven't tried inductor #4 yet.
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