Go to Post I give props to your programmers and programming mentors. - Sgraff_SRHS06 [more]
Home
Go Back   Chief Delphi > Technical > Technical Discussion
CD-Media   CD-Spy  
portal register members calendar search Today's Posts Mark Forums Read FAQ rules

 
Closed Thread
Thread Tools Rate Thread Display Modes
  #1   Spotlight this post!  
Unread 09-01-2002, 23:27
Anne Lam's Avatar
Anne Lam Anne Lam is offline
Registered User
FRC #0368 (Kika Mana)
Team Role: Leadership
 
Join Date: Jun 2001
Rookie Year: 2001
Location: Honolulu, Hawaii
Posts: 49
Anne Lam is an unknown quantity at this point
60 amp breaker

Although the main circuit breaker is rated for 60 Amps, we suspect that we can run our robot at a higher current draw without popping the breaker.

Does anyone have practical experience with exactly how much? 80 amps? 100 amps?

How many total sustained amps do you think we can safely run our robot at?

Since we have a bunch of really powerful motors this year, it seems to me that we really have to watch what we ask of that breaker.

Any help would be appreciated!
  #2   Spotlight this post!  
Unread 10-01-2002, 00:17
Joe Ross's Avatar Unsung FIRST Hero
Joe Ross Joe Ross is offline
Registered User
FRC #0330 (Beachbots)
Team Role: Engineer
 
Join Date: Jun 2001
Rookie Year: 1997
Location: Los Angeles, CA
Posts: 8,574
Joe Ross has a reputation beyond reputeJoe Ross has a reputation beyond reputeJoe Ross has a reputation beyond reputeJoe Ross has a reputation beyond reputeJoe Ross has a reputation beyond reputeJoe Ross has a reputation beyond reputeJoe Ross has a reputation beyond reputeJoe Ross has a reputation beyond reputeJoe Ross has a reputation beyond reputeJoe Ross has a reputation beyond reputeJoe Ross has a reputation beyond repute
at kickoff, woody stated that the breaker will run for about 8 seconds at 200 amps (short circuit current of the batter) and almost two minutes at 100 amps.

Like he said, you have just enough rope to hang yourselves.
  #3   Spotlight this post!  
Unread 10-01-2002, 00:26
Anne Lam's Avatar
Anne Lam Anne Lam is offline
Registered User
FRC #0368 (Kika Mana)
Team Role: Leadership
 
Join Date: Jun 2001
Rookie Year: 2001
Location: Honolulu, Hawaii
Posts: 49
Anne Lam is an unknown quantity at this point
Hi Joe,

Thanks for the information, that should help us figure out how hard we can run the robot.

By the way, how about the 30 amp speed controller circuit breaker. Do these trip at 30 amps?
  #4   Spotlight this post!  
Unread 10-01-2002, 00:54
Patrik Patrik is offline
Registered User
no team
 
Join Date: Jan 2002
Location: Hampton, Va, USA, Earth, The Matrix
Posts: 15
Patrik is an unknown quantity at this point
Send a message via ICQ to Patrik Send a message via AIM to Patrik
I think robot's should use just enough juice to totally discharge the battery after a match . If you're not using that much, you're not using enough. Short circuit the battery if you must. I mean you wouldn't have to worry about recharge memory problems this way. On a more serious note using that much juice that quickly may cause the battery to get rather warm.
__________________
Patrik
To iterate is human, to recurse, divine. -- Robert Heller
  #5   Spotlight this post!  
Unread 10-01-2002, 08:10
Unsung FIRST Hero
Ed Sparks Ed Sparks is offline
Engineer/Mentor/Inspector
AKA: FirstCadLibrary Guy, Inspector Dude
FRC #3959 (Formally with FRC-34)
Team Role: Engineer
 
Join Date: Jul 2001
Rookie Year: 1996
Location: Huntsville, Alabama
Posts: 624
Ed Sparks has a reputation beyond reputeEd Sparks has a reputation beyond reputeEd Sparks has a reputation beyond reputeEd Sparks has a reputation beyond reputeEd Sparks has a reputation beyond reputeEd Sparks has a reputation beyond reputeEd Sparks has a reputation beyond reputeEd Sparks has a reputation beyond reputeEd Sparks has a reputation beyond reputeEd Sparks has a reputation beyond reputeEd Sparks has a reputation beyond repute
Send a message via AIM to Ed Sparks Send a message via Yahoo to Ed Sparks
Exclamation WARNIING !

Quote:
Short circuit the battery if you must
For all those rookie teams out there, Patrik was kidding about shorting the battery. Don't do this! It's a bad bad bad thing (smoke, fire, burning flesh, ruined battery, etc.).


Whew ........
__________________
Ed Sparks

MECH TECH FRC-3959
  #6   Spotlight this post!  
Unread 10-01-2002, 08:21
Tom Fairchild's Avatar
Tom Fairchild Tom Fairchild is offline
Nice Guy
no team
 
Join Date: Jul 2001
Location: Atlanta, GA
Posts: 308
Tom Fairchild will become famous soon enoughTom Fairchild will become famous soon enough
Send a message via AIM to Tom Fairchild
I appoligize for my team mate's suggestion. I'll try to keep him in line in the future.

~Tom Fairchild~, who personally saw one of our other programmers short out a battery which turned into a smoke bomb. Stupid, stupid, stupid......
  #7   Spotlight this post!  
Unread 10-01-2002, 09:41
Patrik Patrik is offline
Registered User
no team
 
Join Date: Jan 2002
Location: Hampton, Va, USA, Earth, The Matrix
Posts: 15
Patrik is an unknown quantity at this point
Send a message via ICQ to Patrik Send a message via AIM to Patrik
Sorry I had thought I made it clear it was a joke.
__________________
Patrik
To iterate is human, to recurse, divine. -- Robert Heller
  #8   Spotlight this post!  
Unread 10-01-2002, 09:59
Kit Gerhart's Avatar
Kit Gerhart Kit Gerhart is offline
Mentor, coach, whatever--
FRC #0233 ("The Pink Team")
Team Role: Mentor
 
Join Date: Nov 2001
Rookie Year: 1996
Location: Cape Canaveral, FL USA
Posts: 559
Kit Gerhart has a reputation beyond reputeKit Gerhart has a reputation beyond reputeKit Gerhart has a reputation beyond reputeKit Gerhart has a reputation beyond reputeKit Gerhart has a reputation beyond reputeKit Gerhart has a reputation beyond reputeKit Gerhart has a reputation beyond reputeKit Gerhart has a reputation beyond reputeKit Gerhart has a reputation beyond reputeKit Gerhart has a reputation beyond reputeKit Gerhart has a reputation beyond repute
Send a message via AIM to Kit Gerhart
Quote:
Originally posted by Anne Lam


By the way, how about the 30 amp speed controller circuit breaker. Do these trip at 30 amps?
The 30 amp breakers will take considerably more than 30 amps for short periods of time, but will heat up and trip much more quickly than the 60 amp breaker if run at, say, 2x its rating. Of course, tripping the 30 amp breakers occasionally is not the "big deal" that tripping the 60 would be, since the 30's reset when they cool down.

If you trip the 30's very often your robot is telling you that something is geared too high.
__________________
Team 45, TechnoKats, 1996-2002
Team 1062, The Storm, 2003
Team 233, "The Pink Team," 2004-present

The views I express here are mine, and mine alone, not those of my team, FIRST, or my previous teams.
  #9   Spotlight this post!  
Unread 10-01-2002, 10:30
Unsung FIRST Hero
Mike Betts Mike Betts is offline
Electrical Engineer
no team
Team Role: Engineer
 
Join Date: Dec 2001
Rookie Year: 1995
Location: Homosassa, FL
Posts: 1,442
Mike Betts has a reputation beyond reputeMike Betts has a reputation beyond reputeMike Betts has a reputation beyond reputeMike Betts has a reputation beyond reputeMike Betts has a reputation beyond reputeMike Betts has a reputation beyond reputeMike Betts has a reputation beyond reputeMike Betts has a reputation beyond reputeMike Betts has a reputation beyond reputeMike Betts has a reputation beyond reputeMike Betts has a reputation beyond repute
Check the data sheets that come as an appendix to the robot rules.

All circuit breakers (and fuses for that matter) have an "inverse time" curve. They have an extremely small but accurate internal resistance which heats up via the power dissipated in this small resistance (P=I*I*R). The actual trip mechanism is thermal.

Be warned that the internal heat does not dissipate quickly. If you run at 200A for 6 seconds and then try running at 100A, you will trip in a lot less time than the quoted 120 seconds (more like 20-30).

This warning also applies to self resetting 20 and 30A circuit breakers. Once they start tripping, they will re-trip in a very short time at the same amperage.

Lastly, these are not "precision" devices. Variations of +/- 30% are not uncommon. Plan accordingly.

Mike
__________________
Mike Betts

Alumnus, Team 3518, Panthrobots, 2011
Alumnus, Team 177, Bobcat Robotics, 1995 - 2010
LRI, Connecticut Regional, 2007-2010
LRI, WPI Regional, 2009 - 2010
RI, South Florida Regional, 2012 - 2013

As easy as 355/113...
  #10   Spotlight this post!  
Unread 10-01-2002, 14:54
smokescreen smokescreen is offline
Registered User
FRC #2360 (POWERStorm)
Team Role: Photography
 
Join Date: Dec 2001
Rookie Year: 1997
Location: Indy
Posts: 44
smokescreen is on a distinguished road
smoke?

We always seem to trip breakers from gearing things badly every couple of years.

So this year we are going to have a "breaker clip" for some of our heavier draw breakers. The custom circuit board will detect the open/close condition of the breakers by measuring the voltage drop across it. When a breaker is found to be open, the board tells the controller to change out the open breaker with one from the breaker clip. As of now, the process is a tad slow with the breaker change rate at about 3 breakers per minute. We're trying to up the rate to about 6 breakers per minute.

Maybe we can get the electrical team to come up with a sound effects generator to make the breaker change sound cooler.

Lastly, what's wrong with smoke! We've smoked plenty of components before.

-smokescreen
__________________
No! Don't let the MWS out!
  #11   Spotlight this post!  
Unread 10-01-2002, 15:13
ttedrow's Avatar
ttedrow ttedrow is offline
Herding electrons
AKA: Tim Tedrow
FRC #0281 (EnTech)
Team Role: Mentor
 
Join Date: Jan 2002
Rookie Year: 2000
Location: Greenville, SC
Posts: 165
ttedrow will become famous soon enoughttedrow will become famous soon enough
Exclamation batteries

The batteries used for the competition do not have a memory problem like NiCad batteries. These batteries do not like to be fully discharged either.
__________________
Sr. Design Engineer
Caterpillar Inc.
Greenville, SC

KD4EGM

FRC 281 Greenvillains
Infected with the FIRST virus in 2000

Yes, Chute Door!!!
Closed Thread


Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Keyang Motor Thermal breaker. archiver 2000 1 24-06-2002 00:24
60 amp Circuit Breaker Info archiver 2001 1 23-06-2002 22:33
Circuit Breakers ark_1230 Electrical 28 09-04-2002 23:16
Where can I get 60 Amp Fuses -- that look like 30 Amp Fuses? Anton Abaya Chit-Chat 4 12-01-2002 14:09
Chain and chain breaker source? kmcclary Off-Season Events 4 22-10-2001 22:51


All times are GMT -5. The time now is 18:08.

The Chief Delphi Forums are sponsored by Innovation First International, Inc.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright © Chief Delphi