[Grassroots-l] Charging the XO off a dynamo
Arjun Sarwal
arjun at laptop.org
Tue Apr 29 11:25:57 EDT 2008
I am not there yet, though, these are the reasons why I chose to use
Animal power.
It isn't easy for humans (in whatever form or way, using leg or muscle
power) to pump in the required power to charge the XO.
see http://wiki.laptop.org/go/Cow_power
Therefore one can use larger dynamos/alternators to perhaps even
charge more than one XO at a time. We charged 2 XOs easily,
modifications in our setup will allow us to charge 10 XOs
simultaneously. The team on the field is working towards it...
Suggestions/feedback most welcome.
thanks
Arjun
ps -- grassroots people, am I being correct in ccing this list on such
matters ? my apologies if I shouldn't be doing it.
On Tue, Apr 29, 2008 at 8:46 PM, Arjun Sarwal <arjun at laptop.org> wrote:
> >
> > Do you think we should tell the OLPC team that their laptop says it's
> > charging when its actually not? Can anything be done for that? Maybe not.
>
> Richard __is__ the OLPC team who'd be interested to know about this.
> I'm sure he'd be very surprised to hear what you've described....
>
> Thanks for sharing all the details. Please keep us posted about your
> progress on using multiple dynamos.
>
> regards
> Arjun
>
>
>
>
> On Tue, Apr 29, 2008 at 8:40 PM, Holden Bonwit <hbonwit04 at yahoo.com> wrote:
> >
> > So I have some bad news, and that's simply to confirm what you guys thought
> > would be true:
> > the standard bike dynamo can't source enough current to charge the XO.
> >
> > The charge light comes on, and (if the laptop is powered up) the indicator
> > says 'charging' but, in fact, there are zero amps going in. The voltage on
> > the charge line is pulled down to 10 volts as soon as the light pops on,
> > just as you predicted.
> >
> > So there are two possible solutions, and I'm looking into both:
> > First off, someone said they knew of bike dynamos that can output same
> > voltage range with up to 2 amps provided.
> > Second, there is always the option to bolt a second, standard dynamo onto
> > the bike and hope this helps.
> >
> > I just checked the wall wart charger, and now I see that it is 12 V, 1.42 A.
> > Standard bike dyno is 12 V, 0.5 A. So its possible that two in conjunction
> > won't work either.
> >
> > Anyway, just wanted to give an update, despite being a bummer one.
> >
> > Do you think we should tell the OLPC team that their laptop says it's
> > charging when its actually not? Can anything be done for that? Maybe not.
> >
> > -HB
> > ==
> > Holden Bonwit
> > hbonwit at alumni.nd.edu
>
>
>
> --
> Arjun Sarwal
> Intern, One Laptop per Child
> Email: arjun at laptop.org
> IRC: arjs on irc.freenode.net in #olpc, #olpc-health, #sugar
>
--
Arjun Sarwal
Intern, One Laptop per Child
Email: arjun at laptop.org
IRC: arjs on irc.freenode.net in #olpc, #olpc-health, #sugar
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