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Old 07-10-2009, 03:52 AM   #1960 (permalink)
MPaulHolmes's Avatar
Join Date: Feb 2008
Location: Maricopa, AZ (sort of. Actually outside of town)
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Michael's Electric Beetle - '71 Volkswagen Superbeetle 500000
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so, INSIDE the LEM is an op amp? The cable is shielded, but the shielding isn't grounded. Did you notice D8? The purpose of that schottky was to keep the voltage below 5v on the A/D input.

When this happened before, I saw significant improvement when I switched to the LEM 500 (on the crappy control board that had some bad caps on it), so I assumed that the latching was from voltage spikes. I stuck with the LEM 300 because I wanted the improved resolution, and I thought the schottkys (D8 and D9) would take care of any spikes above 5v and below 0v.

I reprogrammed the micro for the LEM500, and installed it, so I'll try it tomorrow morning to see if I can get it to latch up.
kits and boards
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