james wrote:
> Shouldn't be destroyed.
>
> Even if there is an overvoltage condition (beyond 24V), damage should
> be constrained to a fuse on motherboard.
it's better than that: 24V is where we'll stop charging, and perhaps
stop operating -- but the laptop won't be damaged. the laptop will be
fine up to 40V, which is when the fuse will blow:
http://wiki.laptop.org/go/XO_DC_Input#Overvoltage
paul
>
> Attached microscope photograph taken facing the back of the DC input
> connector. Big white device with marking 3R is the fuse, silk screen
> label PF2, replacement should be rated 3A at 125V.
>
> Second set of pads is next, PF1, in parallel, possibly useful if your
> fuse is a different shape.
>
> For continued safety, please replace fuse with required rating, not a
> nail or copper wire.
>
> On Thu, Dec 12, 2013 at 11:48:21PM +0000, NoiseEHC wrote:
> > Thanks for all the answers, I will let you know whether my XO 1.75
> > will be destroyed by the Toshiba adapter... :)
> >
> >
> > On 11/12/2013 20:29, John Watlington wrote:
> > >James is correct about 19V probably not working with an XO-1, but with an
> > >XO-1.75/4
> > >you should be fine up to 24V.
> > >
> > >When running with an input voltage higher than 13V, the battery charger
> > >on the
> > >motherboard runs noticeably hotter. Still within spec at 19V and 45C
> > >ambient,
> > >but you might notice the difference in case temperature near the DC input
> > >plug
> > >if charging an empty battery.
> > >
> > >Cheers,
> > >wad
> > >
> > >On Dec 11, 2013, at 3:09 PM, James Cameron wrote:
> > >
> > >>G'day Andrew,
> > >>
> > >>There is a voltage above which the XO-1 will not charge, which had
> > >>been often encountered by people using solar panels. Along would come
> > >>a cold sunny day, with a greater than normal voltage, and the charging
> > >>would stop.
> > >>
> > >>I don't recall the actual voltage (Richard may remember), but I think
> > >>it was somewhere near 18V, and it varied slightly between laptops.
> > >>
> > >>So it might work, or might not.
> > >>
> > >>Instead of using a resistor, you might use two or three large diodes
> > >>in series, each of which will provide a "forward voltage" 0.6V drop.
> > >>Pick the diodes based on the maximum current 1.85A (usually double
> > >>that), and the power that will be released as heat; P = V x I, where V
> > >>is 0.6, and I is not to exceed 1.85A, so 1.11W minimum "power
> > >>dissipation". Place them in a way that does not hold the heat in.
> > >>
> > >>https://learn.sparkfun.com/tutorials/diodes
> > >>
> > >>p.s. if you find one diode does what you need, then add another in
> > >>case of variation in the supply or laptop. You might even add a
> > >>full-wave bridge rectifier instead of two diodes, that way the input
> > >>polarity won't matter.
> > >>
> > >>On Wed, Dec 11, 2013 at 01:52:54PM +0000, NoiseEHC wrote:
> > >>>Hi!
> > >>>
> > >>>I am thinking about using my laptop's charger instead of the OLPC
> > >>>charger in the future as I move a lot and it's getting really
> > >>>tiresome to bring both chargers with me. The plan is to create a
> > >>>converter plug and use only the laptop's but it has different
> > >>>voltage levels.
> > >>>
> > >>>laptop: TOSHIBA
> > >>>part: PA3715U-1ACA
> > >>>model: PA-1750-24
> > >>>output: 19V - 3.95A
> > >>>
> > >>>XO-1.75: DARFON
> > >>>model: BBOJ-C
> > >>>output: 13.5V - 1.85A
> > >>>
> > >>>So can I plug my XO to the TOSHIBA adapter? The page says that
> > >>>11-18V needed, while the laptop's is 19V. Shall I use a resistor to
> > >>>drop the voltage or is it unnecessary? Power usage is not an issue
> > >>>to me. (BTW I will use the plug from the XO-1's charger, I guess
> > >>>that it did not change in the meantime.)
> > >>>
> > >>>Thanks,
> > >>>Andrew
> > >>>_______________________________________________
> > >>>Devel mailing list
> > >>>Devel@lists.laptop.org
> > >>>http://lists.laptop.org/listinfo/devel
> > >>--
> > >>James Cameron
> > >>http://quozl.linux.org.au/
> > >>_______________________________________________
> > >>Devel mailing list
> > >>Devel@lists.laptop.org
> > >>http://lists.laptop.org/listinfo/devel
> >
>
> --
> James Cameron
> http://quozl.linux.org.au/
> part 3 text/plain 129
> _______________________________________________
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> Devel@lists.laptop.org
> http://lists.laptop.org/listinfo/devel
=---------------------
paul fox, p...@laptop.org
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