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Unread 22-01-2017, 18:15
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: 10,808
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Re: Separate Powered Flashlights?

Sorry I haven't had time to check in on CD for a few days. Work got in the way...
In no particular order,
FRC chose the wording "one battery" as a engineering challenge. I started in FRC when we were still using battery powered drills for drive and each drill used it's own battery. When FRC moved to the current battery (which BTW has a very good energy density) laptops were prohibitively expensive items to put on robots as well as video cameras. As the cost of these items fell, FRC changed rules to allow these devices with integral batteries to be used if the battery was not also connected to robot systems like drive or control. They still needed to be included in robot weight as they are now.
LED rings can be "super bright" or my term "mini-sun" and be objectionable. However, the majority of teams using LEDs control them so they are only illuminated when needed. "Self defense" flashlights are by definition "blinding" illumination. We had a lot of feedback from mentors and from UL that these devices put our teams and volunteers at risk of temporary and/or permanent eye damage. And many of those people pointed at a rather lengthy document highlighting the risks, recommendations and support for not using these devices in certain applications. The rule is a response to those who helped point us in the direction of safety.
Many people who simply read about "super capacitors" and think they are a way to circumnavigate the rules are surprised when the capacitor doesn't perform as expected. Large capacitors have an internal resistance that does not allow them to supply large amounts of current over even a few seconds. They take significant energy and time to charge and are meant to supply energy for short duration dips in voltage or to supply a voltage to a circuit that requires very little current. (in the nano-ampere range) The equations for charge and discharge of capacitors are all that is needed to analyze if a super cap will work in your application.
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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.
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