[Peripherals] Charging the XO off a bicycle dynamo

[Matt York]

Although auto alternators amy be somewhat abundant, they are not well 
suited for human or animal "spinning".
Automotive alternators are design for high RPMs; at 2000-2500 RPM, 
alternators are putting out about 60-70% of their capacity.
This forced the Cow Power test to get sidetracked into developing 
excessive pulleys and belts.
Even if they had succeeded, the maintenance of the belts and pulleys 
(over the useful life of the device) would be extremely burdensome.

If labor is cheap and the supplies are available, the rewinding of an 
automotive alternator is a better use of resources.
http://www.mtmscientific.com/rewind.html

Also....
Stepper motors can be used as genertors requiring lower RPMs. Stepper 
Motors have an advantage that they have multiple poles, allowing 
generating useable electricity with low rotation speed, thus eliminating 
the need for gears or belts when cranked by people or cows.
While stepper motors, when used as hand-cranked generators, require 
multi-phase rectifiers, these rectifiers are far easier to make than gears.
http://www.c-realevents.demon.co.uk/steppers/stepmotor.htm

"Smart drive washing machine motors" can be converted into low RPM 
generators.
http://www.ecoinnovation.co.nz/c-45-manuals.aspx


Enlightening the world with technology,
Matt York
Executive Director
www.ompt.org 



Edward Cherlin wrote:
> Has anybody looked at the Playpump schoolyard merry-go-round and
> worked out what it would take to convert it into a generator and
> either use the electricity to charge XOs, or store it for later use?
>
> http://www.playpumps.org/
>
> On Fri, Jan 2, 2009 at 10:11 AM, Sameer Verma <sverma at sfsu.edu> wrote:
>   
>> On Fri, Jan 2, 2009 at 9:13 AM, Matt York <myork at ompt.org> wrote:
>>     
>>> Sameer,
>>>
>>> Thanks for your response.
>>> After reviewing the web page on Cow Power, I can't understand how the Cow is
>>> attached to the prototype.
>>> Does the cow walk in a circle around a pivot like this image?
>>> http://www.worldwideflood.com/ark/technology/ox_mill_small.jpg
>>>
>>>       
>> Indeed. The cow/buffalo/bull/donkey walks in circles rotating the main
>> shaft. The prototype isn't quite complete, as far as I could tell when
>> I visited Khairat last year. Arjun could tell us more on where it
>> stands and what else needs to be done with it.
>>
>> --
>> Sameer
>>
>>     
>>> Or does the cow pull the prototype behind on wheels (like a Tonga cart)?
>>>
>>> Enlightening the world with technology,
>>> Matt York
>>> Executive Director
>>> www.ompt.org
>>>
>>>
>>>
>>> Sameer Verma wrote:
>>>       
>>>> On Thu, Jan 1, 2009 at 9:50 PM, Matt York <myork at ompt.org> wrote:
>>>>
>>>>         
>>>>> *Arjun Sarwal wrote:
>>>>> *
>>>>>
>>>>>
>>>>>           
>>>>>> We switched over to using an alternator from a dynamo in our cow power
>>>>>> setup because of similar issues mentioned below.
>>>>>>
>>>>>>             
>>>>> How are you spinning the alternator? Do you have images or video of the
>>>>> linkage/drive train?
>>>>>
>>>>>
>>>>>           
>>>> Here you go! http://wiki.laptop.org/go/Cow_Power
>>>>
>>>> Sameer
>>>>
>>>>         
>>
>> --
>> Dr. Sameer Verma, Ph.D.
>> Associate Professor of Information Systems
>> San Francisco State University
>> San Francisco CA 94132 USA
>> http://verma.sfsu.edu/
>> http://opensource.sfsu.edu/
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>>
>>     
>
>
>
>