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Unread 14-01-2008, 07:48
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Al Skierkiewicz Al Skierkiewicz is offline
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AKA: Big Al WFFA 2005
FRC #0111 (WildStang)
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Re: Current Clamping Code and Hardware

Quote:
Originally Posted by jee7s View Post
If you don't want to use them, a toroid inductor around the supply wire will give you an indirect measurment of current flowing through the wire. Keep in mind that this output will be polar, so you'll need to bias it to get the data into the RC with validity.

-JEE
Jeff,
The toroid pickup only works on AC current, no transformer action takes place on DC (except in the transition during power ON). We used the Maxim high side current monitor with a one foot piece of #10 as the sense lead. (a sense wire at each end. Ironically, 100 amps in 1 foot of #10 is 0.1 volt drop.)
As Jim has pointed out, the circuit breakers are very forgiving and auto reset. You might want to consider a software/control switch. Design the mechanical system for a lower speed at something less than full throttle. Then with the push of a button on the joystick, apply full power for top speed. Highest currents are usually encountered when starting, when changing directions, or when pushing. However, sticky tires and tank drive push currents to near stall on all drive motors when turning. I expect to see some effects of this during the game this year due to the mandatory turns in the game.
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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.