Alt-BEAM Archive
Message #13290
To: beam@sgiblab.sgi.com
From: "Bruce Robinson" Bruce_Robinson@telus.net
Date: Mon, 10 Apr 2000 18:00:23 +1000
Subject: Re: a water + light powered aqautic robot?
> Meabadboy@aol.com wrote:
> >
> > In a message dated 4/9/2000 10:58:41 PM Eastern Daylight Time,
> > davidperry@geocities.com writes:
> >
> > << Imagine this mechanism, a chamber is filled up with water
> > and solar power slowly takes out the hydrogen (by electrolysis)
> > which builds up in the robot (epoxy chamber) where a spark
> > ignites it, which sends water rushing out, projecting the robot
> > a long long way, wherer the process begins again. Perhaps ahead
> > of its time but quite possible.>>
> >
> > Not really ahead of its time ~ however, it would have be sorta
> > like the storage of the strobe circuit of a flash ~ like that
> > of a camera flash circuit
> >
> > What u could try is to store up a voltage level in a cap ~ then
> > if you can get it to convert that stored voltage to a high voltage
> > with low Amps (like a spark) ~ you could fire it into a chamber and
> > bubble off hydrogen and oxygen ...
>
> This idea is just a variation on "Use solar energy to make electrical
> energy to separate water into it's component gases, then burn the gases
> to produce mechanical energy to drive the robot." That's 6 energy
> conversions: solar to electrical to stored electrical (capacitor) to
> chemical to thermal to mechanical (engine) to mechanical (propellor).
> Each conversion loses energy due to inefficiencies.
>
> David's idea is fundamentally different. Instead of storing electrical
> energy in a capacitor, he's storing it in chemical form (even small
> currents at low voltages will electrolyze water). There's only 3 energy
> conversions here: solar to electrical to stored chemical to
> thermo-mechanical (combustions acts like a rocket engine).
>
> You can't store hydrogen forever, it will leak through anything
> including several inches of solid steel. However, I suspect you can
> store it a lot longer than you can store electrical energy in a
> capacitor.
>
> David's idea might not work too well for underwater designs, because
> your robot would tend to float when a lot of gas was stored, and sink
> when the gas was exhausted ... just when you want it floating to get the
> maximum benefit of the sun. For surface robots ... why not?
>
> Bruce
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