[Stoves] Hand Crank Dynamo for Fanned Stove?

[Niels Petersen]

The fingers are not working well this morning. I really should check my
typing before pressing the send button :-(   300 milliamps = 0.3 amp

On 12/5/07, Niels Petersen <nielspt at gmail.com> wrote:
>
>
> Milliamps !   milli = 1000 Therefore 300 milliamps = 0.3 amp
>
> Maybe you should reconsider your following statements
>
> --
> Kind Regards
> Niels Petersen
>
>
> On 12/5/07, Charlie Sellers <csellers42 at yahoo.com> wrote:
> >
> > Paul,
> >
> > If you really are pulling the full 300 milliamps (.3 amps) at 12 V then
> > that amount of "power" is just the product of these two, or about 4
> > watts.  For comparison a single ordinary LED will need MUCH less than one
> > watt and the WoodGas stove fan needs a little more than 1 watt.  So your 4
> > watt need is quite a bit of power.  Are you sure that your PWM duty cycle is
> > 100%, and not less than that?  As you turn it up from no power to full power
> > the duty cycle (or percentage of time that the PWM turns the power on) goes
> > from 0% to 100%, increasing the fan speed proportionately.  An ordinary
> > multimeter will not tell you duty cycle, so you can't use it to determine
> > the power you are consuming.
> >
> > This got more complicated than I thought (so I deleted much of my
> > discussion on LED circuits, units of measure, and calculating the energy per
> > crank), but it was not a simple question.  The bottom line is what is the
> > amount of energy that can be stored in the internal battery (voltage times
> > the milliamp-hr battery rating) and how many cranks does it take to fully
> > charge the battery?  Then determine how you will compensate for the lower
> > voltage of the battery (perhaps much less than 12 V).  Some homework is
> > required, and my gut feel is that all the LEDs in the latern take very
> > little power, compared to 4 watts.
> >
> > My issue with solar battery charging and similar gadgets is that these
> > are just more pricey parts to break when you are in a developing country -
> > and the batteries themselves are just more parts to be diverted to other
> > applications (like radios, then new rechargeable batteries may not be
> > available to replace them for the stove).  I carry a slim 110/220 VAC
> > battery charger with me, but fan stoves just may not be suitable for many
> > places because they are somewhat high tech for now.  Cell phones at least
> > are priming the world for small appliance and battery charging. Internal
> > thermoelectric power is one approach to less parts, if a lifetime can be
> > predicted when used in the field.
> >
> > Charlie
> >
> >
> > "Paul S. Anderson" <psanders at ilstu.edu> wrote: Stovers,
> >
> > >> Jeff Davis wrote:
> >
> > >>> Found an interesting product at Harbor Freight. It's a hand crank
> > LED
> > >>> lantern.
> > >>> Crank for 60 seconds and get 20 minutes of light.
> >
> > For the blower in my TLUD in India, I need 300 milliamps at 12 volts DC
> > maximum
> > power, and I "turn it down" with a PWM (pulse width modulator) that has
> > a 500
> > milliamps maximum.
> >
> > Question:  How many minutes of 300 milliamps 12 volt power can I get
> > from
> > existing hand-crank devices?
> >
> >
> >
> >
> >
> > ---------------------------------
> > Be a better sports nut! Let your teams follow you with Yahoo Mobile. Try
> > it now.
> > _______________________________________________
> > Stoves mailing list
> > Stoves at listserv.repp.org
> > http://listserv.repp.org/mailman/listinfo/stoves_listserv.repp.org
> > http://stoves.bioenergylists.org
> > http://info.bioenergylists.org
> >
>
>
>


-- 
Kind Regards
Niels Petersen