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philc
Apr 24, 2001, 11:42 AM
Been following the discussion on power down the lines and ECL.

Lithium batteries have sufficient power density to make a workable CL plane- I mean one that can take off easily, do some maneuvers with authority, and fly for at least 3 min. The only problem is that they can only handle ~2 amps. At 3v per cell, or 6 watts, you would need something like 20 cells to deliver ~120 watts that would fly a half A size plane pretty well. I believe the standard Li cells weigh about .75 ounces, and could be arranged in a 4x5 battery, four rows of 5 cells which would deliver 15 volts at about 8 amps. that is getting close, but would be expensive.

You could also call one of the wire companies like American Standard to see what it would take to produce a cable with either an aluminum or silver center strand. Or perhaps 4 aluminum strands and 3 stainless. If you do the calculations I think this would get the resistance down enough that 30 volts or so could provide enough power down the lines. But has anybody thought about what would happen if the insulation on the lines cracked or wore through? The lines would probably explode, and the short circuit might even blow up the battery!

dr.E
Apr 28, 2001, 07:23 AM
Our developments for an ECL running on "hot wires" have been directed toward trainer type aircraft for kids. It is easier to have a large capacity powersource on your belt that provides hours of running time than to supervise 20 kids trying to charge separate battery packs.

The AMA asked us to conduct a pull test on the copper stranded lines (5 lbs). We tested them to 8lbs without failure.

What concerns me about aluminum or copper lines is metal fatigue.