Posted by Jim Wilkins on June 5, 2011, 5:15 pm
As long as the locals who've learned to do this haven't all found jobs
overseas. I have to wonder why so many doctors from needy countries
are practicing here instead.
And yes, I know about the lack of national as opposed to family or
tribal identity, and the crab-in-a-bucket syndrome.
Posted by Winston on June 5, 2011, 5:40 pm
Jim Wilkins wrote:
I suppose that each situation is radically different.
One village might have a genius that repairs
stuff by salvaging parts, but not a good source of
valuable raw material. Another village might be situated
right next to a eWaste dump but not have the necessary
technical knowhow to salvage productively.
Posted by Winston on June 5, 2011, 10:30 pm
Morris Dovey wrote:
That's a nifty circuit.
Troubleshooting and repair would be *much* easier if a few key
'test points' were brought out to pads.
Perhaps the board could be laid out with '3 patterns per part' so that
salvaged parts in any package could be used. Pads for an SO transistor
would live right next to holes for a through-hole transistor, would
live right next to largish flat pads to connect an electrically
equivalent, mechanically incompatible transistor.
Aesthetic nightmare but functional. I resemble that remark!
Creating tools and techniques for salvaging parts in the field is
left as an exercise for the student. :)
Posted by MickyJf on June 12, 2011, 3:23 pm
Thanks for all the valued input Morris, efforts such on such magnitude
are never in vain. My 2 cents,
- I've a keen interest in Thermosiphon solar tech, for commercial and
businesses - such low cost on investment - to return. Looking at whats
possible to have array's working in series to achieve high value
temp.s with my supplier.
- Maybe the 'readily available approach is a bridge to far, a working
- real world prototype is sufficient, allowing more time to cope with
energy 'bleed' as all reactions / engines suffer from and reach a
manageable figure = work gained.
- most important is the approach of standing back, take your mind in
different directions and the answer sometimes appears! I think they
call them eureka moments.
Again many thanks for all the updates and knowledge shared.
Posted by Morris Dovey on June 13, 2011, 1:01 pm
On 6/12/11 10:23 AM, MickyJf wrote:
You're welcome. Fluidynes may be useful for light-duty applications, but
I'm trying to solve a heavy-duty problem. They've been a good learning
exercise and it might well be that I'd never have been able to arrive at
a satisfactory solution without that experience.
My own efforts in this direction have been much helped by focusing on
energy aspects of the problems, rather than directly on temperatures -
and by thinking of temperature as a measure of energy density.
Perhaps - but the amount of solar energy available per unit area is
sufficiently low that losses become a hugely significant part of the
problem. It's fairly easy to design an engine with a pretty respectable
Carnot efficiency, and then have real-world losses shrink that
efficiency down to just a few percent.
I've had a lot of fun trying to find ways to take advantage of the loss
mechanisms so that they contribute to, rather than detract from, overall
There is at least an element of zen, and the most important part of the
exercise (for me) has been to formulate questions to identify my own
ignorance - then look for answers to those questions with the goal of
coming up with still more questions (and again and again). During solar
panel development, for example, it was when I began asking questions
like "What is sunshine, really?" and "Exactly what is it about a
comfortably warm room that makes it so?" that I started having those
eureka moments more often than every once in a while. :-)