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Unread 12-02-2011, 21:39
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Matt Krass Matt Krass is offline
"Old" and Cranky. Get off my lawn!
AKA: Dark Ages
FRC #0263 (Sachem Aftershock)
Team Role: Mentor
 
Join Date: Oct 2002
Rookie Year: 2002
Location: Long Island, NY
Posts: 1,187
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Re: Reading Battery Voltage

Quote:
Originally Posted by jee7s View Post
I don't have one in front of me right now, but I seem to recall that the inputs to a Jaguar use red and black screws and the outputs are colored green and white. The "black" terminal I was referring to was the input side of the Jaguar.

And, Al's right, there's no "ground" in the most literal sense on the robot. My use of "ground" could have probably been better worded as the EE colloquial "virtual ground" (i.e. the node of the circuit from which voltage is measured) or as "common". The chassis being electrically isolated (therefore there is no ground) is an important and sometimes overlooked detail in the FRC.
Ah, that makes sense. I tend to kind of associate black to common in my head (which always seems to make for a bad day when I have to change a switch or light socket) so between that and you saying motor terminal, I misunderstood a bit.

The robot being isolated has lead to some interesting hilarity when abruptly grounded by a serial cable in the past, on the IFI control system. We had an amusing set of circumstances that truly and completely isolated the robot on a work table, and just unfortunate luck of having lots of little charges brought to it. By the time we grounded that sucker, it was.... not fun.
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Matt Krass
If I suggest something to try and fix a problem, and you don't understand what I mean, please PM me!

I'm a FIRST relic of sorts, I remember when we used PBASIC and we got CH Flightsticks in the KoP. In my day we didn't have motorized carts, we pushed our robots uphill, both ways! (Houston 2003!)