Philip & Marilyn wrote: > Does any one run their laptop directly from the house mains? The > output from my power brick says 17 volts, but the internal battery > supplies 14.4 which most likely drops to less than 13.8 when under > load - so nominal ~13v dc aught to run it. Question is where to make > the connection. Just plug into the power inlet in the back like the > brick does? > > Any problems with this hook--up? > > Thanks > Philip > REPLY: You are going have trouble with that approach. your laptop plug in > power supply has an output of 17 volts for a reason. There are voltage drops > associated with its opeation. your statement of "so a nominal ~ 13V aught to run it" ignores a lot of realities of 12V systems. Your 12V DC system will never see 13V unless a charging source is running. Which means you must either be docked and plugged in or your engine is running. Secondly running "barefoot" ie feeding DC from ship's power directly int your laptop is dangerous because of the noise spikes and power surges toy normally get in a DC system. You might get lucky but I would not give your laptop a three month life span if you do that on a regular basis. Just because you plug it in and run a ten minute test doesn't mean you will be same success when underway or at anchor. Just wait till some 12V appliance turns on or off.
One of the reasons manufacturers changed to higher than 12V in their power supplies was to foil any attempts to do exactly what you propose. Too many sales people plugged their lap tops into the car's cigarette lighter socket and blew up their laptop. My old Toshiba had the ability to run directly from 12VDC.Next model released was 18V supply. If you really do not want 120V aboard, why not install a small 500 Waty sinewave inverter to feed your computer stuff only. The inverter will power any reasonable office computer system like laptop, a printer/copier and such like. It makes it much more convenient to get shore power compatible equipment on board. And when you are docked and plugged into shor epower it provides one additional level of buffering between your computer stuff and any lightning strikes into the shore utility power wiring. I would assume you do have some lightning surge protection aboard in any case if you cruise in lightning prone areas. _______________________________________________ Liveaboard mailing list [email protected] To adjust your membership settings over the web http://www.liveaboardnow.org/mailman/listinfo/liveaboard To subscribe send an email to [EMAIL PROTECTED] To unsubscribe send an email to [EMAIL PROTECTED] The archives are at http://www.liveaboardnow.org/pipermail/liveaboard/ To search the archives http://www.mail-archive.com/[email protected] The Mailman Users Guide can be found here http://www.gnu.org/software/mailman/mailman-member/index.html
