Go to Post Anything is capable of happening in FIRST. - Dorienne [more]
Home
Go Back   Chief Delphi > Technical > Electrical
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
  #16   Spotlight this post!  
Unread 22-02-2012, 14:15
Unsung FIRST Hero
Al Skierkiewicz Al Skierkiewicz is offline
Broadcast Eng/Chief Robot Inspector
AKA: Big Al WFFA 2005
FRC #0111 (WildStang)
Team Role: Engineer
 
Join Date: Jun 2001
Rookie Year: 1996
Location: Wheeling, IL
Posts: 10,798
Al Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond repute
Re: Wiring a Fisher Gear Motor

OK,
Time to correct some items here.
1. The Victor has a lower switching frequency which does not react to motors with a higher winding inductance. It is this interaction which gives the Jaguar it's seemingly more linear response.
2. When used with PWM, both controllers have the same limitations in discrete steps. The max being ~127 in each direction less whatever deadband is in use. The hobby/servo PWM standard provides for this step count.
3. The Jaguar seems to react with the locking pins in the window motor. While documented, there is no real study of what is actually occurring. My personal opinion is that the switching frequency causes the pins to vibrate and alternately lock in place while the motor is driving.
4. The Jaguar uses FETs with lower "on" resistance but in the newer devices has reduced the parts count to two per leg instead of three. I will have to search back through my files but as I remember the Victor is 0.006 and the Jag is 0.004 ohms series resistance.
5. The Jag uses current sense and under internal software control will disable output when the current exceeds a set point. See the Jag spec sheet for details. The Victor does not sense current so the very small resistor used in the Jag is not present in the Victor.
5. Size is self explanatory.
6. The Victor does not have CAN at the present time. Customers have been asking for it.
7. Neither device has reverse polarity or output protection.
8. The Jaguar requires a very short reverse pulse when at full throttle to keep the bootstrap cap charged. It does not affect the available output power.
__________________
Good Luck All. Learn something new, everyday!
Al
WB9UVJ
www.wildstang.org
________________________
Storming the Tower since 1996.
  #17   Spotlight this post!  
Unread 22-02-2012, 17:43
s_forbes's Avatar
s_forbes s_forbes is offline
anonymous internet person
FRC #0842 (Falcon Robotics)
Team Role: Engineer
 
Join Date: Jan 2006
Rookie Year: 2006
Location: Phoenix, AZ
Posts: 1,156
s_forbes has a reputation beyond reputes_forbes has a reputation beyond reputes_forbes has a reputation beyond reputes_forbes has a reputation beyond reputes_forbes has a reputation beyond reputes_forbes has a reputation beyond reputes_forbes has a reputation beyond reputes_forbes has a reputation beyond reputes_forbes has a reputation beyond reputes_forbes has a reputation beyond reputes_forbes has a reputation beyond repute
Re: Wiring a Fisher Gear Motor

Quote:
Originally Posted by Ether View Post
The Jag's output curve is just as "smooth" and far more linear than the Vic's, as can be seen here.
Thanks for the link. We were wondering why our new drivetrain is so phenomenally easy to drive (same layout as last years bot, but controlled by black Jags). I no longer see any reason to use Victors.
  #18   Spotlight this post!  
Unread 22-02-2012, 18:01
Ether's Avatar
Ether Ether is offline
systems engineer (retired)
no team
 
Join Date: Nov 2009
Rookie Year: 1969
Location: US
Posts: 8,125
Ether has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond repute
Re: Wiring a Fisher Gear Motor

Quote:
Originally Posted by s_forbes View Post
Thanks for the link. We were wondering why our new drivetrain is so phenomenally easy to drive (same layout as last years bot, but controlled by black Jags). I no longer see any reason to use Victors.

FYI:

If you find yourself using Vics and are unhappy with the output response curve, you can adjust the joystick values to compensate:

http://www.chiefdelphi.com/media/papers/2421


  #19   Spotlight this post!  
Unread 23-02-2012, 22:49
Ekcrbe's Avatar
Ekcrbe Ekcrbe is offline
When can I watch Einstein again?
AKA: Erik Boyle
FRC #4640 (Metallic Panthers)
Team Role: College Student
 
Join Date: Jan 2012
Rookie Year: 2012
Location: New York, NY
Posts: 334
Ekcrbe has a reputation beyond reputeEkcrbe has a reputation beyond reputeEkcrbe has a reputation beyond reputeEkcrbe has a reputation beyond reputeEkcrbe has a reputation beyond reputeEkcrbe has a reputation beyond reputeEkcrbe has a reputation beyond reputeEkcrbe has a reputation beyond reputeEkcrbe has a reputation beyond reputeEkcrbe has a reputation beyond reputeEkcrbe has a reputation beyond repute
Re: Wiring a Fisher Gear Motor

Thanks for all the discussion about Jaguars and Victors, but that's a good topic for another thread. I hope we can wrap this up now.

P.S. - Another reason I prefer the Jaguars for our drive and shooter motors is that we are running CAN to them, which shawnz brought to my attention again.
__________________
Four years of FRC 68 Truck Town Thunder
2012 Championship Newton Division Finalists—Thanks 330 and 639 for the Full Court Press!
2013 Kettering University District Chairman's Award Winners!
2014 Great Lakes Bay Region District Winners—Thanks 288, 4819, and 5166! | 2014 Waterford District Chairman's Award Winners! | 2014 Michigan FRC State Championship Chairman's Award Winners—Congratulations 33 and 503!
2015 Center Line District Chairman's Award Winners! | 2015 Lansing District Winners—Thanks 314 and 1684! | 2015 FIRST in Michigan District Championship Chairman's Award Winners—Congratulations 503 and 2137!


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


All times are GMT -5. The time now is 19:57.

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