Thread: Batteries Plus
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Unread 29-10-2012, 08:19
Mark McLeod's Avatar
Mark McLeod Mark McLeod is offline
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FRC #0358 (Robotic Eagles)
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Re: Batteries Plus

Quote:
Originally Posted by Al Skierkiewicz View Post
Please remember that the 12 volt connection to the Crio analog module and the jumper on that module are used to sense the battery voltage and provide the reading on the dashboard. If the voltage dips to about 5.5 volts, the Crio disables all output, which temporarily stops all motor function. If the battery voltage falls to 4.5 volts for a short duration, the power supplies that feed the Crio, camera and radio will reset and so too will the devices they feed.
Not quite right.
The battery voltage fed in through the Analog breakout to the cRIO is not used by the cRIO to cut power at low voltage. The cRIO isn't involved at all. That's why your robot will run without power to the Analog breakout-you just get a 0.00 volts reading at the Driver Station.

At low voltage the Power Distribution Panel is the element that lets power drop to the regular red/black wago connections on the PDP, while sustaining full power through just the two special 12v radio and 24v cRIO outputs. The power to the 5v (nominally the camera connection) is not protected. The motors lose their power, at least momentarily until the battery recovers, while the radio and cRIO resist rebooting until the battery falls below the minimum threshold.
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Last edited by Mark McLeod : 29-10-2012 at 09:48.