Quote:
Originally Posted by Trez
What is usually the bear minimum volatge that the cRIO or the wireless router starts to reset? Is it like 10 volts?
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Trez,
The power supplies in the PD which feed the Crio, the Wireless Bridge and the camera drop out at ~4.5 volts at the battery input to the PD. The Crio is programmed to disable all outputs at 5.5 volts in order to try to protect itself from reboot. Heavy motor use will pull the battery down to these critical levels for short periods of time without causing any problems, but a robot that is not designed with efficiency in mind, will cause some or all of these items to fail without warning.
A Crio disable is pretty obvious with a sudden jerky movement or response under driver control. If the battery goes down to less than 4.5 volts for more than a moment, the Crio and/or wireless bridge and/or camera will reboot. The Crio can take anywhere from 20-60 seconds to reboot depending on your software. The wireless bridge can take up to 50 seconds or more to reboot and reconnect to both FMS and the Crio. The power supplies will restart very quickly when the battery returns to more than 5-6 volts.
Please remember, the battery has some internal resistance, your wiring has some resistance, the circuit breakers have some resistance. When you pull a lot of current from the battery, the current passing through all this resistance will drop the voltage available to critical items like the Crio and wireless bridge power supplies. #6 wire has ~0.0005 ohms per foot and the battery has 0.011 ohms at full charge and room temperature. An average robot with 4' (both red and black musst be considered) of #6 with four CIMs in stall while pushing another robot will drop a minimum of ~5.2 volts in the resistance in just those components taking the available voltage to 6.8 volts at full charge.