Thread: IR Board Power
View Single Post
  #4   Spotlight this post!  
Unread 07-02-2008, 14:05
Mark McLeod's Avatar
Mark McLeod Mark McLeod is offline
Just Itinerant
AKA: Hey dad...Father...MARK
FRC #0358 (Robotic Eagles)
Team Role: Engineer
  
Join Date: Mar 2003
Rookie Year: 2002
Location: Hauppauge, Long Island, NY
Posts: 8,801
Mark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond repute
Re: IR Board Power
Two basic FIRST legal choices are allowed (and adequate) for powering the IR Receiver:

1) Power from the 12v breaker panel, protected by a 20amp breaker (power from the main 12v battery)

2) Power from one of the 7.2v "PWM Output" pins on the Robot Controller (powered by the 7.2v backup battery)

Choice #2 does risk having too little power as the backup battery is close to the lower limit, but will work if you keep the backup battery fully charged at all times. Choice #1 could also fail if a motor surge drops the main battery voltage too low, so keep that battery fully charged as well!


There is a third legal variation to power the board from one of the 5v Robot Controller pins (powered by the main 12v battery and backed by by the 7.2v backup battery), e.g., Analog Inputs or Digital I/O pins, however, this does involve modifying the IR board to bypass the on-board 5v regulator. The advantage here is double battery coverage since any extreme 12v battery drop will be covered by the backup battery.
__________________
"Rationality is our distinguishing characteristic - it's what sets us apart from the beasts." - Aristotle
Last edited by Mark McLeod : 08-02-2008 at 10:44.
Reply With Quote