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Unread 11-03-2009, 12:43
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
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Re: possible solution to the static problem

Erik,
Since the gun is the source, what did tests did you perform that led you to this conclusion? If the floor can be modeled as a series of capacitors, what is the other plate of the capacitor and why would a 28x38 robot frame not also be part of the capacitive equivalent circuit? I can agree with the series resistor part, but at the insulation level of fiberglass and gel coating and the material's inability to absorb moisture, the series resistance must be pretty high. i.e.>100Mohm. I have done a cursory check on electrical characteristics of this material and so far I have not found any. However, looking at the gel coating and polymer base material as likely being similar electrical properties, I am guessing the surface resistivity to be in the 10^12 ohms/cm or higher. In putting all the reports together (and in the absence of better testing) I am guessing that the static is a condition of the carpet to FRP transition rather than the robot to FRP. If this is the case, then a drag chain will not be effective until the chain contacts the carpet at the field borders. Should this be the case, then chains should be effective if applied to multiple points on the exterior dimensions of the robot, to insure charge drains off prior to a robot to field border interaction.
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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.