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Old 17-10-2007, 05:45   #61
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The OLPC XO laptop seems like it might be a very rugged & durable alternative:
One Laptop per Child (OLPC), Laptop: A learning tool created expressly for the children in developing nations

One Laptop per Child (OLPC), Laptop: A learning tool created expressly for the children in developing nations

Starting November 12, One Laptop Per Child (OLPC) will be offering a Give 1 Get 1 Program for a brief window of time in North America. For $399, you will be purchasing two XO laptops—one that will be sent to empower a child to learn in a developing nation, and one that will be sent to your child at home.
Goto: One Laptop per Child (OLPC), a $100 laptop for the world's children's education
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Old 17-10-2007, 12:40   #62
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I use a Toshiba laptop with an Intel® Pentium® M Processor. Battery life is terrific as it's in the 4 to 5 hour range. Power Brick is 19v @ 3.4 A.

Using Searclear II navigatation software this provides a very large and easy to use display.

Compared to the price of a decent size chart plotter, I believe modern laptops are a better alternative. From reading this thread it would seem that a concensus is developing along these lines as everyone is arriving at the same conclusion.
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Old 24-10-2007, 08:00   #63
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i wonder if computer companies carry a "waterproof" or a protective casing for us....if not, they should...you would probably have to call a manufacturer
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Old 24-10-2007, 08:58   #64
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Vinn, you can't just "waterproof case" a dynamic system like a laptop. You need to provide for active airflow or other cooling, among other problems like cable entry. Case in point a "simple" Ikelite classic underwater camera housing can cost you more than most laptop computers--and they don't need any cooling.

The only real way to make a laptop water resistant is in the design stage, like some of the Panasonic Toughbooks or some of the real marinized versions from small-name vendors who build hermetically sealed laptops for use in damp and dusty locations (i.e. for process control in a cement mine, where alkaline dust gets into everything.)

Figure about $2-4,000 for "older slower" technology when it has to be environmentally cased that way, especially if you want a screen that's easily read in daylight.

There's a lot to be said for keeping the laptop below (or in a closed bridge deck) and just using a PDA in an otterbox or ewa bag topsides, with a radio link if needed. Still won't be cheap, but much easier to keep the computer dry.[g]
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Old 24-10-2007, 10:15   #65
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Right now the research boat that I skipper has 4 desktop computers on board and anywhere from 1 to 3 laptops on board depending on what we are doing. Just keep your computers inside and get a waterproof monitor for outside use. I have never had any moisture or humidity problems with any of the computers. Google "waterproof monitor", there are lots to choose from.

I have the computers secured down with velcro tape.

In my opinion, Nobeltec makes the best PC based chart software. It's the most intuitive and versatile.

You don't need to get fancy with power for the laptop. Many laptops can use multiple DC voltages. Find one thats rated up to 14 volts and connect it directly to your DC system. If not, get one of those cigarette lighter style 12 volt to whatever voltage you need power converters. Radio Shack sells one with your choice of output voltages. Make sure the charger is going to cover the maximum current draw of your laptop. The maximum amps DC will be listed on the 120V power supply that came with the computer. That may not be the maximum amps your computer will actually draw but if you match that number on the power supply then you will be covered.
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Old 24-10-2007, 20:13   #66
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Originally Posted by GordMay View Post
The OLPC XO laptop seems like it might be a very rugged & durable alternative:
One Laptop per Child (OLPC), Laptop: A learning tool created expressly for the children in developing nations

One Laptop per Child (OLPC), Laptop: A learning tool created expressly for the children in developing nations

Starting November 12, One Laptop Per Child (OLPC) will be offering a Give 1 Get 1 Program for a brief window of time in North America. For $399, you will be purchasing two XO laptops—one that will be sent to empower a child to learn in a developing nation, and one that will be sent to your child at home.
Goto: One Laptop per Child (OLPC), a $100 laptop for the world's children's education
Which processor do they use?
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Old 24-10-2007, 20:35   #67
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CPU: x86-compatible processor with 64KB each L1 I and D cache; at least 128KB L2 cache; AMD Geode LX-700@0.8W (datasheet);
One Laptop per Child (OLPC), Laptop: A learning tool created expressly for the children in developing nations

LOW POWER consumption. These may be hand cranked afterall. The slowest one uses 1.3W normal and 3.1W TDP.

Power Management - OLPCWiki
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Old 25-10-2007, 00:06   #68
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last time I checked they had an optional pull cord system for charging. The pull cord operated similarly to one on an outboard motor, except smaller and easier to use, and you'd pull it constantly for a minute or more to get power I believe in a 1:10 ratio. 1 minute of pulling for 10 minutes of use, or something like that. They moved away from the crank idea after finding it difficult to design a crank which wouldn't easily break off.
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Old 25-10-2007, 01:13   #69
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The XO is pretty light weight hardware and runs a special light weight version of the Linux OS. To the best of my knowledge, none of the navigation software runs on Linux. There is software that available for Linux that runs Windows programs but they tend to be real resources hogs. I doubt that the XO could be configured to satisfactorily support onboard navigation requirements.
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Old 25-10-2007, 05:19   #70
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last time I checked they had an optional pull cord system for charging. The pull cord operated similarly to one on an outboard motor, except smaller and easier to use, and you'd pull it constantly for a minute or more to get power I believe in a 1:10 ratio. 1 minute of pulling for 10 minutes of use, or something like that. They moved away from the crank idea after finding it difficult to design a crank which wouldn't easily break off.
From the website.
In addition, —for use at home and where power is not available—the XO can be hand powered. It will come with at least two of three options: a crank, a pedal, or a pull-cord. It is also possible that children could have a second battery for group charging at school while they are using their laptop in class.

I'm not sure what the final release will have, but it sounds cool to have multiple options.

Chris
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Old 25-10-2007, 05:21   #71
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The XO is pretty light weight hardware and runs a special light weight version of the Linux OS. To the best of my knowledge, none of the navigation software runs on Linux. There is software that available for Linux that runs Windows programs but they tend to be real resources hogs. I doubt that the XO could be configured to satisfactorily support onboard navigation requirements.
This thing is a long way away from being ready for normal software.
I'm not suggesting that this will be a good fit for sailing, but I still really like the concept. And it may help normal Windows laptops become more effecient.

There are multiple groups working on a similar concept to one laptop per child mainly b/c of money. They expect to sell hundreds of millions of these, so you don't have to make a lot of money per unit to be successful.
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Old 25-10-2007, 06:25   #72
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I'm not suggesting that this will be a good fit for sailing, but I still really like the concept. And it may help normal Windows laptops become more effecient.
I don't think that you'll be seeing any of the main stream laptop makers using cpu's like the AMD Geode LX series because of the low computing power. The trend is to sell machines with higher power.

Laptop efficiency probably bottomed out with use of the ULV pentium M's. The Uxxx series Core Duo/Core 2 Duo CPU's are not far behind but bottom line is that they use more power than the ULV Pentium M's. They do provide a lot more computing power but it is wasted on most boat oriented applications.

You can buy or build your own SFF machine based on the AMD Geode LX cpu. I have a machine based on the LX800 in the shop and running a slim combo DVD/CD, 40 GB HD, and 512 mb ram it uses 9-11 watts running an old version of the Capn'. With an LVDS monitor running the whole system only uses 17 watts.

The LX800 will run all nav software, communications software, weather fax, office suites etc. What it won't do is play a DVD smoothly and I would'nt consider it for a fully integrated system with radar overlay using Nobeltech, Raymarine or Maxsea/furuno. The graphics section isn't up to it.

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Old 25-10-2007, 18:27   #73
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any idea of how much you would save with DC to DC option?
I have never bothered to measure it but I suspect it is generally not much and depends -

The first thing is that people go wrong in assuming that the DC to DC step up power supplies are a "one conversion step" device and go direct from 12 v DC to the higher DC voltage whereas that is incorrect. This claim is made in every thread about these devices but, in fact, they actually convert from the 12volt DC to AC first using similar technology to a small inverter (using a buck converter device) and then convert that AC back to DC at the required higher voltage.

So whether one uses an inverter together with the notebook manufacturer's AC to DC power supply or one of the 12 volt step up supplies there are exactly the same number of conversion steps - three, being DC->AC->DC. So, in the end, the overall conversion efficiency will depend on the efficiency of each of the devices used, not on whether one goes the inverter/power supply or the DC to DC converter way.

As I say I have never bothered to do any checks, mainly because I too believe, as another has said, any difference between the two approaches is likely to be small in terms of efficiency. As was also said the DC to DC converters seem to be quite inefficient whereas inverters are generally very efficient (but that depending on size and type and how well they idle when left on with no load) - I would not be surprised if going the inverter way is often the most efficient, but in the end I don't fancy that either way there is enough in it to actually worry about and I never have.

The most efficient way is, of course, to run the notebook straight off the boat's 12v as others have suggested. If you look at the voltage of the notebook's battery you will usually find that it is a multiple of approx 3.8v (assuming Lithium Ion) and generally approx 11.8 volts (being 6 cells made up of 2 x 3 cells in parallel) or, less frequently but for high end machines, approx 15.2 volts (being 8 cells made up of 2 x 4 cells in parallel). These voltages are, of course, lower than the manufacturer's AC supply output voltage (usually around 18.5v or 20 something volts respectively).

In the few I've tried and all those reported back to me by friends, six cell notebooks (ie battery around 11.8v) work happily on 12v from the boat and if seen in the light of if the notebook is not on its power supply it has to work on around 12 v from its battery this seems common sense (but there are always exceptions to common sense ). The higher voltage from the notebook's power supply seems to be only relevant to charging the battery. Also not often appreciated is that the batteries are internally regulated (Lithium Ion always are so due to the risk of precipitating Li) so that as long as one stays within the manufacturer's charge voltage (ie the 18.5 volt or whatever) it is not likely possible to overcharge them. I suspect they are all, certainly in recent times, also regulated against complete discharge, maybe someone knows.

I would be careful if powered directly off a small house 12 v battery bank with large inductive loads on it though, or if powered from the cranking battery when cranking as there is not any isolation from spikes that could normally be provided by the external supply normally used by the notebook (ie the manufacturer's supply or the DC step up supply discussed). We have a simple and cheap automotive surge protector installed across the +ve and -ve of our DC house supply and doing so may provide some protection from spikes.

As an aside, a friend and I have tested a number of notebooks (all HP/Compaq or Compaq) in the range around 1.2 to 1.9 GHz for current draw. We found all the ones we tested drew around 1.8 to 2 amps when running a typical program with hard drive access and the battery already fully charged - this is much less than many claim (without, I assume, actually measuring it, but just quoting from the power supply rating). Of course a higher current is drawn if the battery is under charge but this is not energy lost except the little from the losses in the charging process itself and if wished to avoid that little loss then one can always remove the battery.

Hope that is of some help.
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Old 26-10-2007, 06:37   #74
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I have had laptops aboard for the last 14 years, and find that obsolesence, not the marine environment, is usually the cause for their replacement. It doesn't make any sense to buy a marinized version as long as you don't use it on deck.

There is a huge difference in power consumption between makes and processors--the Fujitsu with core duo processor I am using now only draws 2-3 amps through a small inverter, compared with 7-10 for my P4 Gateway (the large inverter has much too low an efficiency at low power, and small inverters are cheap). The only time we run the laptop off its internal battery is when we are recieving email and wfax over the SSB--our experience has been that most internal batteries less than 2 years old will last the 20 minutes or so that this requires, particularly when you boot up on the inverter.

Underway we use the laptop for electronic charts, email, weatherfax, AIS, and other non-boat uses--most of the programs and charts are free downloads. When at anchor or in a marina, we are increasingly using wifi to connect to the internet, through a Hawking HWU8DD directional antenna which plugs into a USB port and we put up under the dodger. The computer is probably on an average of 2-3 hours per day.
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Old 26-10-2007, 12:47   #75
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Just found this news item about putting XP on the XO. This could make the XO a nice little backup nav engine.

Even with Linux on the XO it might be possible to use VNC remote desktop software to operate the nav computer from the cockpit. Which might be pretty slick! I just wish the XO wasn't green.
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