(This thread starts here - all subsequent posts are relevant to the OLPC "$100 laptop" project).
I have recently come from a presentation at a local company by someone who is directly involved in the OLPC effort. The news I can report is:
1. They have given up on claiming that the device can be powered by a hand crank, although they realize that since this is a highly publicized aspect of the design they will have to speak of it as "optional".
2. There will be a few thousand development systems produced in a few months and at present the project has no idea as to how to distribute them.
3. Much software work will lbe needed to adapt software to reduce waste of memory resources. Firefox was cited as eating huge amounts of memory (64MB for a clock applet, 600MB usage after a days' work e.g.). These kinds of problems can no longer be waved away by citing Moore's projection (I refuse to give any "law" that is implemented by humans the status of a law of nature).
4. The project needs someone to handle the immense task of organizing the necessary infrastructure (servers in all the hinterland schools with backhaul Internet communications and power sources). I briefly toyed with the idea of offering my services in this area, but I have never marshalled armies and would hate to become the scapegoat for the project's failure.
5. The primary justification is given as providing electronic textbooks which can be amortized by five such uses (on the assumption that each textbook costs $20 - a figure which I would question). They disclaim any responsibility for the contents of the textbooks, and I still find myself haunted by the thought that this project would establish the continuously-revisable textbook as a way to place history firmly under control of central governments.
In short, while I am pleased to have played a small part in bringing some engineering reality to the power issue, the OLPC project seems to be rolling along on its own momentum without any significant change of focus. But it is still early in the process, with interesting doses of reality yet to come.
I hope that JD Baldwin does not think that I claim that a laptop cannot run at all on a battery charged by a hand crank. The question is how long the laptop (or any load of a few watts) will run on a charge generated by how much cranking against how much resistance. I have published my calculations in this blog - nothing any critic has said here has contradicted them.
Please, if you feel that I am wrong, address the calculations. Your statements should be reviewed by someone with basic electrical engineering or physics skills (it doesn't take much).
The crank power issue is dead now, as witness the statement 1) above. I am working on development of a pedal-powered generator which can generate 60 - 70 watts of power over extended periods of time. There has been recent progress on this and I will report on it when I have permission fromothers who are involved.
Posted by: Lee Felsenstein | April 07, 2006 at 10:16 AM
A laptop batteries can be recharged by a hand crank. Also a clockwork 'battery' system could power a low end laptop, as below:
On a BBC program - "tommorows world " late 1980s/early 90s they had Trevor Bayliss of the windup radio fame on. Where he had slightly modified one of his radios with power out up socket on the back. Guess what, he plugged a laptop into the socket and it worked.
Posted by: J D Baldwin | April 05, 2006 at 12:34 AM
Just a small clarification: the $20 textbook number often cited is how much the Brazilian government currently spends each year per child in textbooks (several per child). So if the Laptop can replace all books for five years in a row with no extra costs it would break even.
Posted by: Jecel Assumpcao Jr | February 24, 2006 at 08:20 AM