I wonder how a tablet really fits the Xo mission beyond PR? The G1G1, while flawed in a few ways, made an attempt at least to put a programmable machine in the hands of third world children and empower them to be content creators.
A tablet is inherently a content consumer device, not a creator device. This is the secret to Apple's success with them. (They have been chasing this particular horse since the early Mac days. Mac was never supposed to be a creator device, that was the ill fated Lisa.) I cant imagine anyone typing much code on a touch screen keyboard. Is the goal of OLPC now to create more consumers? JK On Tue, Jan 10, 2012 at 6:28 PM, Richard A. Smith <rich...@laptop.org>wrote: > On 01/07/2012 06:40 PM, Alan Eliasen wrote: > > > I'm also curious about the power claims. What is its power > > consumption and charging requirements? > > Its still much too early to lay out exact claims for this. These are A1 > prototypes. This is the stage where we start finding all the things that > are using more power than we would like and try to reduce them. The exact > size of the battery is also changing as we maximize the space in the > battery cavities. > > We don't/won't start making any exact claims on power until it moves well > into the B and C series builds. > > That said, a lot of the internals are almost identical to the 1.75 so the > things I've previously said about 1.75 are going to be a good approximation > of the XO-3. As John indicated the traditional display does consume more > power than the Pixel-Qi. > > In case you missed my previous comment on 1.75 on devel@ the maximum > runtime power draw of the 1.75 is 5W. (Not including the extra 5W you can > draw from the USB port.) > > The power input front end of the XO-3 is currently identical to the > XO-1.75 which matches the specifications of XO-1.5. 11V-25V input range > and a maximum input rating of 25W. Unlike the XO-1.5 the XO-1.75 almost > never gets to the 25W maximum because its runtime power is much lower. So > the peak power draw only happens if its charging a very low battery. > > One difference between the XO-1.75 and XO-3 is that the XO-3 can _also_ be > powered by USB On-The-Go (OTG). OTG has a strict 5V/7.5W power > specification so charging via OTG will take longer. No. I've not yet > measured how much longer. :) Sadly its not a nice linear thing that you can > just do the math and figure out. There are many variables some of which > will change with the next prototypes. > > Having a robust, wide voltage range, high power input is an important > feature when using alternative power sources. Alternative power can be > very unclean and very sporadic. You must be very forgiving on what you > allow and when its available you want to maximize your input. > > I don't think any other tablet made so far would survive long term if you > connected it directly up to an automotive 12V power system. > > > > Has it actually been > > demonstrated to be chargeable by "solar panels, hand cranks and other > > alternative power sources?" Especially ones not requiring systems which > > cost many times more than the price of the laptop, nor require someone > > with the green skin color of the XO to crank. > > This claim isn't really new. Evey XO generation we have made to date > matches this claim. In each generation we made an improvement over the > previous. > > Its always been possible to charge an XO from alternative power sources. > There are sites in Rwanda, Peru, Haiti and the Solomon Islands (just to > name a few) that are powered entirely by solar. These are using XO-1 and > XO-1.5. Some of these use a more commercial type solar system and some > just are just raw solar panels that connect directly to the XO. > > The XO-1 and XO-1.5 both had maximum runtime peak power draws in the 10W > range. Running things like the camera activity which keeps the system busy > would draw that power continuously. If you didn't have 10W of input you go > backwards. Most people don't really realize how much work 10W of > continuous power is. The physical size of a 10W solar panel isn't huge but > its still pretty large and you need perfect solar conditions for that 10W. > So what you really need is a 20W solar panel that so that a wide range of > solar conditions still work. A 20W panel is pretty large and not something > easy to lug around. > > The 1.75 (and tablet) have a runtime peak power draw in the 5W range and > they idle even lower. So now devices that produce power in the 10W range > can fully power the new XO devices in a variety of conditions. So you can > envision taking an XO outside into the field connected to smaller solar > panel (say 5-7W) and have a net power draw very close to zero. A 10W panel > would almost certainly have a net draw of zero unless the solar conditions > were really terrible. > > In my testing here in Boston I have powered a 1.75 directly (no battery) > from the OLPC 10W panel in January sun. Here's a video Chris Ball and I > shot Jan 9, 2012 showing a 1.75 completely powered by our 10W thin-film PV > panel. > > http://www.youtube.com/watch?**v=ITHNbOrPQyM<http://www.youtube.com/watch?v=ITHNbOrPQyM> > > Hope this info helps, > > -- > Richard A. Smith <rich...@laptop.org> > One Laptop per Child > > ______________________________**_________________ > Devel mailing list > Devel@lists.laptop.org > http://lists.laptop.org/**listinfo/devel<http://lists.laptop.org/listinfo/devel> > -- It's always darkest just before you are eaten by a grue.
_______________________________________________ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel