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Unread 12-04-2011, 10:16
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Richard Wallace Richard Wallace is offline
I live for the details.
FRC #3620 (Average Joes)
Team Role: Engineer
 
Join Date: Jan 2003
Rookie Year: 1996
Location: Southwestern Michigan
Posts: 3,623
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Re: Unexplained loss of motor power while valves work.

Quote:
Originally Posted by apalrd View Post
Digital Sidecar has metal shavings (or something else) shorting out the 5v line. When shorted (or overcurrent), the 5v supply shuts down to protect itself from destruction. ...
Sure looks like you lost the Sidecar. Shorting out the 5V rail is the most likely cause. Sometimes the Sidecar will protect itself when this happens, but it is also possible for ICs inside it to fail -- that happened to us at MSC. Two ICs showed pitted plastic tops, and that familiar smell of magic smoke, after we drilled through the red wire on one of our PWM cables coming from the Sidecar. Fixed the cable, replaced the Sidecar, good to go, lesson learned: don't hide cables where drills can find them!
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Richard Wallace

Mentor since 2011 for FRC 3620 Average Joes (St. Joseph, Michigan)
Mentor 2002-10 for FRC 931 Perpetual Chaos (St. Louis, Missouri)
since 2003

I believe in intuition and inspiration. Imagination is more important than knowledge. For knowledge is limited, whereas imagination embraces the entire world, stimulating progress, giving birth to evolution. It is, strictly speaking, a real factor in scientific research.
(Cosmic Religion : With Other Opinions and Aphorisms (1931) by Albert Einstein, p. 97)