[Peripherals] Electricity (was Re: The rest of the puzzle)

[Edward Cherlin]

Thank you, Javier. Excellent analysis. I'll ask some people who know
more about this than I do what options they can find.

On Mon, May 19, 2008 at 11:15 PM, info at olpc-peru.info
<info at olpc-peru.info> wrote:
> Alternators:
>
> Wind energy: low RPM alternators.  That is what you need.
> Water energy: low RPM alternators, again.
> Human (animal): low RPM alternators, the same....
>
> All the alternators used in wind or water devices are low RPM (to the best
> of my knowledge... low RPM is around 600 RPM).
>
> Option a) 2nd hand alternators from trucks and old cars.
> Alternators that come from cars and trucks are 3,000 RPM and more.
> Modification is needed.
>
> You can modify the alternator (some models) to get lower RPM by doing this:
> a) Adding more magnets (IF the structure of the alternator allow to add more
> magnets)  or...
> b) Adding more wired copper coils... (IF the structure allows it).
>
> Copper coil is available in Peru in many places, no problem.  Magnets ARE
> NOT available easily.  Some source for cheap magnets should be found.
>
> 2nd hand alternators can be found in many places in Peru at US$55 and up.
> Reason: there is a huge market for 2nd hand car parts.
>
> My main concern is that for modifying a high RPM car alternator you need
> some extra skills and extra tools.
>
> Option b) 2nd hand alternators from small cars
> Then we have low RPM alternators.  Unlucky we are that these alternators
> (and this kind of cars) have a huge demand in Peru (it doesnt matter if the
> car is 20 years old, it works and it will find a market).  So I have ask, a
> long time ago, and new alternators for this cars cost US$300 and 2nd hand
> can be found from US$100 each.

I see. And you can't get them from the US, because most people would
say that the labor to get them out of junked cars, plus the shipping,
would make them just as expensive in Peru. I will talk to some other
people about that.

> So here we have them: 600 or 700 RPM alternators that are too expensive for
> the development of the solution.
>
> Option c) Build your own alternator.
>
> It is totally possible.  You only need magnets, coiled copper wires and some
> basic skills.  You can check how it is done by artisan methods.
> The only "not available" part are the magnets (they should be imported from
> China).  Then a design and a plan could be delivered (with spare parts
> (mainly the magnets and the copper coil) to the town that will manufacture
> its own alternator by themselves.
>
> Option d) Import your own low RPM alternators.  I have send email to some
> chinese manufacturer of low RPM alternators, without luck (because I think
> they are looking for bigger markets).
>
> Option e) Modify the design of the "mechanical" device, so... with the use
> of pulleys and other gadgets you can "amplify" the RPM that you need to work
> with a normal car or truck alternator (high RPM alternator).  This involves
> design of mechanics and physics laws that goes beyond my skills and that can
> be a burden for the humble peasants in the high mountains.  But any engineer
> will see as an "easy task".  I ask myself what difficulties can show up from
> the "improved design" due to heavy weights or more "pulleys" that need to be
> moved.  In this case we are "rebuilding" the origin of the industrial
> civilization (that comes from the use of one spinning wheel with human
> movement, to the use of 6 spinning wheels with the use of the very same
> human movement, then they took "running water" to move up to 120 spinning
> wheels (because human forces was not efficient), then they took steam and
> finally electricity to move 500 or more spinning wheels.  That was the start
> of the industrial revolution.  No problem to rebuild the whole process
> because these high Andes communities are tied exactly to the year 1821 (that
> was the year of our "independence" from the Spaniard colonial power... the
> old Spaniards (due to his economy system) keep "updated" those communities
> with the last customes and uses that were normal in those year, it is the
> "republic" that forgot that these communities exist and you can find them in
> the same (or worse) conditions that they had in 1821).
>
> Option f) There are some low RPM alternators that are used for industrial
> purposes.  I ask about them here in Peru, but the cost is US$700 and up.
>
> Finally, a human been (treadling or pedaling) in a normal spinning wheel can
> produce around 500 RPM.  I have not calculated how much RPM can be produced
> in a bicycle, but the problem with bicycles is that you are moving the whole
> leg, then you are "wasting" too much energy and you can not sustain the
> movement by a long time.
>
> Other info: I have found that you need 600 RPM devices to keep the whole
> thing in a realistic enviroment.  It is possible to get energy from lower
> RPM but then you have to add too many magnets and too much copper wired
> coils and the weight of the "turning wheel" increase and the price of the
> components increase.  The best of my experience tell me that 600 RPM is what
> we need to look for.
>
> I hope it helps.
>
> Javier Rodriguez
> Lima, Peru
>
>
> Javier, please find out what used alternators go for from junkyards in
> Perú. Here is one other data point. "The cost of a Delco CS-130
> alternator at any US junkyard should be $10.00 to $15.00 US."
> http://bernardembden.com/xjs/altmove/index.htm
>
> When I ask you whether it is better to curse the darkness or to teach
> people to make candles, I don't want to hear you grumbling about the
> lack of candle-making materials. If we don't have candlewax, we will
> make oil lamps or coal fires or something. I just want a direct answer
> to the question. Are you in or out? Are you ready to work toward
> solutions, or not? OK?
>
>
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-- 
Edward Cherlin
End Poverty at a Profit by teaching children business
http://www.EarthTreasury.org/
"The best way to predict the future is to invent it."--Alan Kay