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Armadillo Aerospace News: Digital IO board, Big vehicle work, 50% H2O2 success
We were doing a dry test run on the small vehicle when we noticed that the drogue ejection actuator was behaving very erratically. It turned out to be a solder blob that had landed on the PC104 board during the re-soldering of our secondary power input. Our attempt to repair it wound up killing the entire board, so I replaced it with a newer IO board (a WinSystems UIO-48). This board didn’t seem to work at all, but after some investigation, we found that it was functioning correctly, but that it just couldn’t drive the 15 mA needed to trigger the opto-isolators on our driver board. Looking at the specs, it only claims to source 2.5 mA, so it isn’t surprising. What was surprising was that the first board we were using also only listed 2.5 mA source, so we don’t see how that worked at all. The board (a WinSystems IO-48) must have additional buffering, but we decided to change vendors and get a board that was actually rated for what we were using. Read More

posted by Sigurd @ 6/08/2003 03:46:00 AM