Does anybody know if it is within the rules to use a voltage regulator on the robot between the battery and the controller to prevent the controller from automatically powering down if the supply voltage is under 7.5V?
The backup battery should take care of this problem.
It is not legal to connect a custom circuit to the power input of the robot controller anyway.
Firstly, the components known as voltage regulators tend to regulate voltage downward–like a 15 V supply regulated to 12 V.
Secondly, you have a backup battery connector on the RC which is intended to serve this purpose. Connect a 7.2 V battery (such as the one from the Robovation kit) to the RC, and it will power it, even if the main battery is depleted.
ok, thanks, that’s what i was wondering about mainly, the custom circuit.
And yes i am aware that the backup battery will take over, but it seems that the controller tends to power off before it switches to the backup battery. Well, i guess i’m only talking about when we are drawing a significant amount of current from the battery and the voltage temporarily drops. If the voltage drops slowly the backup battery works then.
That is precisely why FIRST/IFI added the 7.2V Nicad battery. It keeps the controller running even if an external short or load brings the 12V down to zero.
You should do this experiment. power up your robot with both a 12V and the 7.2V battery installed. Now disconnect the 12V. Your controller will continue to operate until you either disconnect the 7.2V battery OR press the RC reset button.
You do not need a regulator.
In reality there is an internal regulator built into the controller. If you are drawing significant currents and drawing the voltage down so far that the backup battery takes over, you have some other problems to correct. The controller switch is just a symptom of a bigger problem. It might be as simple as a loose connector on the battery or a poorly made crimp on the wires feeding the controller. But it could be something wrong in you mechanical systems. Find the cause and fix it.