[Stoves] Powering a TLUD Fan

Thu Aug 30 17:02:03 CDT 2012

Josh,

Could a hand-crank or foot treadle system be operated at a village level?
It might be too expensive for a household.
Do you know of companies that make them?

Paul Olivier

On Thu, Aug 30, 2012 at 10:59 PM, Josh Kearns
<yeah.yeah.right.on at gmail.com>wrote:

> What about a mechanical hand-crank or foot-treadle system with a flywheel?
> Get 'er goin and then every few min. a couple pumps on the crank to keep
> the flywheel up to the desired speed.
>
> Josh
>
>
> On Thu, Aug 30, 2012 at 9:42 AM, Phil Hughes <nicafyl at gmail.com> wrote:
>
>> Let me toss in a few more factoids.
>> http://www.batteryspace.com/li-ioncylindricalcellseries.aspx will give
>> you a decent sample of the common LiION cells. The most common size in
>> laptop batteries is the 18650 which is typically from 2.2 to 2.78Ah. When
>> you see a laptop with a higher capacity battery it is typically cells in
>> series-parallel. For example, a 6-cell battery is generally two strings of
>> three 18650 cells in parallel.
>>
>> The explosing fist is real. The good news is that there are very
>> inexpensive chips designed to charge these cells. You will find one (for a
>> single cell) in all cellular phones. They will deal with maximum voltage
>> and maximum charge current. They are also low drop-out as a typical use is
>> to output 4.2V from a USB (5V) supply.
>>
>> In a typical laptop, you find other chips (generally more than just a
>> single component) to charge the "almost 12V" string of LiIon cells from the
>> typical 16 to 20V AC adapter. The disadvantage here is that you need to
>> monitor the voltages of each cell in the string. Not complicated but that
>> is what makes the 12V solution potentially more expensive than the 3.7V one.
>>
>> A 5V fan is an interesting possibility. First, if may operate fast enough
>> from say 3.5V so a single LiIon cell would handle it. If not, a flyback
>> converter to step up 3.7 to 5V would be cheap and high efficiency (because
>> most of the power comes directly from the battery rather than needing to be
>> "converted").
>>
>>
>> On Thu, Aug 30, 2012 at 9:36 AM, Frans Peeters <peetersfrans at telenet.be>wrote:
>>
>>> Phil,
>>>
>>> 3x LiION  =3,7Vx3=11,1V  Charger needs 4,2x3=12,6 maximum or EXPLOSION
>>> RISK
>>> 2W motor at 12V-------->0,1666 A
>>> 8h xO,166A =1,8Ah
>>> Laptop cells are 3,6 Ah and more
>>> Sun cell 15,6V---------> 12,6 V +3V for charging  regulator LM317
>>>
>>> PC  uP fans exist at 5V x0,2A=1W you could power with 2 cells;
>>> Also a dual fan of 2x 1W
>>>
>>> Regards
>>> Frans
>>>
>>> I see Paul Oliver's work to be excellent and appreciate how a variable
>>> speed
>>> fan can offer excellent control over TLUD operation. My reservation is
>>> that
>>> there are many places where even the small power requirement (Paul says
>>> 1-2
>>> watts) just isn't available. Lots of people here in Nicaragua are totally
>>> off-grid and don't have reasonable access to a way to charge a battery.
>>> So,
>>> I am been thinking about options. Being, among other things, an
>>> electronics
>>> geek, here is what I have been thinking about.
>>>
>>>
>>> Running the TLUD 8 hours a day at "average" fan speed means 12 watts per
>>> day. At 12 volts that's one ampere hour. I have been thinking about a
>>> couple
>>> of approaches. One is "higher tech" but may be a better solution at an
>>> equivalent or lower cost. In both cases I am just thinking of a
>>> photovoltaic
>>> panel to charge the battery. The difference is the battery voltage.
>>>
>>> Small PV panels are pretty common on the surplus market. For example,
>>> Electronic Gold Mine (http://www.goldmine-elec.com/) offers an
>>> assortment.
>>> The specifications vary from 7 to 35 volts open circuit with output
>>> power in
>>> the range of 1-3 watts. Prices are from $4.50 to $15. As this is quantity
>>> one retail price information, it is likely the could be found at
>>> significantly lower costs.
>>>
>>>
>>> As any PV-based system will need some sort of charge controller for the
>>> battery and what PV cells (in particular, what voltage) will be
>>> available at
>>> the best price point, I am thinking that using a single-cell Lithium Ion
>>> battery (3.7 volts nominal) would make the most sense. Units with a
>>> capacity
>>> of 2.2 ampere hours and more are commonly used in laptop computers. They
>>> offer reasonable life, low cost and the possibility of finding them on
>>> the
>>> surplus market. The cells can be paralleled if higher capacity is needed.
>>>
>>> A switching "up-converter" would be needed to supply the 12 volts needed
>>> for
>>> the fan. The speed control could be incorporated into the up converter
>>> which
>>> would reduce the cost and increase the efficiency.
>>>
>>> The alternative would be to use a more or less 12 volt battery (three
>>> Li-Ion
>>> cells in series) so that the up-converter could be eliminated. My initial
>>> guess is that the reduced electronics cost would not be as much as the
>>> increased battery cost but it is a viable alternative as long as higher
>>> voltage surplus PV panels are available.
>>>
>>> While this sounds like a lot of electronics, this is all very common
>>> stuff
>>> that you find in, for example, cellular phones. There is some design work
>>> needed but the actual component costs will be very low.
>>>
>>> Comments?
>>>
>>> --
>>> Phil Hughes
>>> nicafyl at gmail.com
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> Stoves mailing list
>>>
>>> to Send a Message to the list, use the email address
>>> stoves at lists.bioenergylists.org
>>>
>>> to UNSUBSCRIBE or Change your List Settings use the web page
>>>
>>> http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org
>>>
>>> for more Biomass Cooking Stoves,  News and Information see our web site:
>>> http://www.bioenergylists.org/
>>>
>>>
>>
>>
>> --
>> Phil Hughes
>> nicafyl at gmail.com
>>
>>
>>
>>
>>
>> _______________________________________________
>> Stoves mailing list
>>
>> to Send a Message to the list, use the email address
>> stoves at lists.bioenergylists.org
>>
>> to UNSUBSCRIBE or Change your List Settings use the web page
>>
>> http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org
>>
>> for more Biomass Cooking Stoves,  News and Information see our web site:
>> http://www.bioenergylists.org/
>>
>>
>>
>
>
> --
> Josh Kearns
> PhD Candidate
> Environmental Engineering
> Engineering for Developing Communities
> University of Colorado-Boulder
>
> Director of Science
> Aqueous Solutions
> www.aqsolutions.org
>
> Mobile: 720 989 3959
> Skype: joshkearns
>
>
>
>
>
> _______________________________________________
> Stoves mailing list
>
> to Send a Message to the list, use the email address
> stoves at lists.bioenergylists.org
>
> to UNSUBSCRIBE or Change your List Settings use the web page
>
> http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org
>
> for more Biomass Cooking Stoves,  News and Information see our web site:
> http://www.bioenergylists.org/
>
>
>

-- 
Paul A. Olivier PhD
27C Pham Hong Thai Street
Dalat
Vietnam

Louisiana telephone: 1-337-447-4124 (rings Vietnam)
Mobile: 090-694-1573 (in Vietnam)
Skype address: Xpolivier
http://www.esrla.com/
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.bioenergylists.org/pipermail/stoves_lists.bioenergylists.org/attachments/20120831/563921c3/attachment.html>