Graynomad:
I believe the original 1-wire instrument switched resistors with its reed switches so as to get unique A/D readings for each direction.
That would make a difference. Still I think removing a magnet would be easier. Maybe add a similar weight to keep the balance.
Rob
Very good. That's exactly what those inscrutable Chinese did. That gray thing that looks exactly like the other one is a dummy. Only one is a magnet.
I'm proud to say I figured it out before I actually verified it. Like Sherlock Holmes said, whenever you've exhausted all the possibilities, whatever is left, no matter how improbable, is the answer.
So maybe that's what the patent is for. 