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Unread 30-03-2010, 14:21
spack spack is offline
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Join Date: Feb 2005
Location: Westtown PA
Posts: 6
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Re: powr dist. board/cRIO puzzle - please advise!

Thanks to all for suggestions.

What I know through monitoring and through some tests before crating are:
- It's not a comms issue.
- It is an interruption or disturbance of power to the CRio due to a high upstream branch current, or some nasty EM kick. The CRio reboots.
- The internal resistance of the battery is far and away the largest feed resistance in the circuit and the (very slow acting) auto-reset breakers are not meant to protect the CRio from an IR drop due to hard short, so no surprise there. Having said that, I did like the alternate battery approach we used to have to help when a battery may have gotten mismanaged. Also having said that, there is no way to know if there was or is a hard short without the robot in front of us. We can only theorize at this point and do what follows figuring that it probably is such a thing or that the commutator is stuffed.

We will be replacing the motor, victor, and using an alternate breaker port out of hand. And we will arrive with new batteries. Isolation will be checked.

I did some bench testing with a surge load while monitoring the 24v supply with a scope. Frankly I don't like the approach. I'd rather the CRio stayed up while our robot was billowing smoke rings.

Thanks again,
Chad