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Unread 01-05-2008, 13:25
jbbjjbt jbbjjbt is offline
VRC Coach
AKA: Jon T
VRC #0177 (Twisted Botz)
Team Role: Coach
 
Join Date: Feb 2006
Rookie Year: 2004
Location: Gloucester, VA
Posts: 110
jbbjjbt is an unknown quantity at this point
Re: [FTC]: Tips for Teams going to the Vex Championships

Quote:
Originally Posted by gblake View Post
Precision is important when using English. Let me see if I can untangle the causes and effects being discussed here.

4 Amps is max current the Vex microcontroller will supply through the sum of all of its PWM/Motor ports.

Attempting to draw more than 4 Amps through the PWM/Motor does not cause a Vex microcontroller to reset.

Drawing current out of the Vex batteries will result in a voltage drop at the battery's output terminals.

If the current drawn is enough to lower the Vex battery's voltage far enough below 5 Volts, the Vex microcontroller will shutdown and be reset when it starts back up.

Sometimes this happens during matches when the loads the motors are experiencing rise and then fall and when the robot's battery isn't up to the task of keeping the robot healthy. The current drawn rises and falls. The battery voltage falls and then rises. The microcontroller shuts down when the voltage drops, and restarts when the voltage rises. At start-up the microcontroller starts executing it's user code, beginning with the first instruction of that code.

Blake
Now, This all makes sense and I believe it.

And this reminds me, Our team, Twisted Bots, owes a big THANK YOU to Blake and his team for loaning us batteries to get us through the finals. Ours gave up.

Blake,
Could you please post details on the battery charger that discharges the batteries so they work better?

Thanks,
Jon T
Coach Team 177
Twisted Bots
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