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Unread 21-09-2011, 08:21
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: 10,766
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Re: Current Draw vs. Stall current

Adam,
I would check your calculations as your result sounds pretty high. The net effect on the Jaguars would be that they would go into current protect mode at that high current. The stall spec on the CIM is 133 amps but generally the wiring teams use and the length of wire will result in lower currents at stall. As to the breakers, they may trip but effectively reset within milliseconds. As suggested the breakers are a temperature controlled device and so can stand loads in the 600% of rated current range for a couple of seconds. However, once at an elevated temperature, the trip point becomes much lower.
I always ask why teams want to go so fast. At 15 fps you will be covering end to end in a little over two seconds. Control becomes an issue and collisions will cause some serious damage. We recommend speeds of 10-12 fps for high gearing as a good balance of speed, maneuverability, control and the ability to avoid potentially fatal collisions. While many teams like to go fast, only a select few do it well.
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Good Luck All. Learn something new, everyday!
Al
WB9UVJ
www.wildstang.org
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Storming the Tower since 1996.