Ron, We have used a laptop for many years and it always runs off the boats 12 volt system. We use a converter power cord that has a 12 volt input with 19 volt output. You can buy them from the computer manufacturer or from Radio Shack. Chuck

To follow our adventures, go to

http://trawler-beach-house.blogspot.com/

http://sea-trek.blogspot.com/

--- On Wed, 1/14/09, Ron Dreher RDreher@roadrunner.com wrote:

Ron Dreher wrote:

I use Coastal Explorer for my nav package, and despite having a pretty
full package of Raymarine nav products, I don't use the Raymarine for
chartplotting or routing. Just too cumbersome. I use CE for all nav
functions, it talks to the Raymarine autopilot, and works very well. I
also use a SeaTalk to RS232 converter, perhaps a bit overkill, but it
does a good job of collecting all the NMEA data and getting it to the
computer with one connection.

After having used ChartView, the predecessor to Nobeltec, I can't say
enough good things about CE. I am presently working with the 2.0 Beta,
and the only complaint is that I don't have enough cash to replace the
Pathfinder radar with a new one that CE can use! The other shortcoming
is that I don't have a monitor on the flybridge, for that I just follow
on the chart on the Raymarine for those areas for which I have the C-Map
chips, another reason I don't use the Raymarine chartplotter.($$ )

Despite all the dire warnings about exclusive use as a nav computer, I
use my tethered Palm Centro to get internet access while underway for
current weather, looking up information on upcoming areas, etc. I've
never had a problem with reliability. I attirbute that to my system
configuration. I generally have less than 40 processes running, I've
seen bloated software and OS setups that have as many as 75 processes
needlessly eating up system resources.

Steve Sipe
Solo 4303 "Maerin"
Lying Vero Beach "./..where the tropics begin"

/

----- Original Message -----
From: "Chuck and Susan" sea_trek_2000@yahoo.com

REPLY

Sorry Chuck;  but you are NOT  using  ship's 12V  power directly for ytour
computer.  What you are using is a dedicated  inverter  that takes raw
ship's power and converts it to  a regulated and stabilized  19V  output
and that is the power  usd by your computer.  Yes it's a termonology quibble
if you wish, but enough people have suffered the consequences of
misunderstanding what is involved to warrant discussion.  We have had this
discussion  a number of times  on this forum.  And we have enough newbies
joining  that it bears repeating every few years

Using raw  "12V" ships power  directly into a computer that has a "12V"
input is dangerous.  It will lead to power supply failure sooner rather
than later.  Just dig into the archives  going back as much as six or more
years and you will  see  the threads.

Ship's  power  consist of  raw unregulated  voltages that range from a high
of 14.2V  ( charging) to a low of  10.5V  (near dead battery )    This is a
considerable swing from the nominal  12.00V  implied by the 12V designation.
Roughly 25%  or so.  Not exactly stable.
The computer has a built in switch mode power supply to derive the required
internal  5.00V  main supply and the -12.00V  memory power.  When the
supply voltage is low, the built in power supply will  draw more current
compared to when the  supply voltage is high. This extra current becme heat
and this is what causes  premature failure of the power supply.  Depending
on what model you have, replacing a power supply can become an expensive
proposition.  Not to mention which,  laptops  are more diffiuclt to get
seviced  compared to  desk top units.  At the very least you have the
inconvenience of  downtime while you ship the laptop out to get serviced.

The  special power cords  such as you use  are expensive.  They are not
always available if you ever damage or lose one.
If you have  a desk top computer  or a laptop with a "wall wart" power cube,
the easiest solution is to plug into the regular inverter.
If you are  particular about power consumption  and want to save every watt,
then get a dedicated  littel inverter (preferably a sine wave)  of around
300 - 500 watts capacity.  These units will be at their most efficient
conversion rate  at about the same power level as what the computer uses.
Parasitic load current  will be minimal using a dedicated inverter.

As a general thing I suggest getting one of the small sine wave inverters
because some  of the power bricks  sold as universal power  supplies  have a
nasty habit of  cooking themselves in short order when powered from MSW
inverters.

How do I know al this?  Because I usd to work for a manufacturer that made
these power cords  and house branded them for a number of retailers like HP,
Targus etc.  In  my job as their  marine application engineer I handled
seveal complaints  regarding these very issues.

regards
Arild

I use a home built desktop with a quad core AMD cpu 4GB ram and a 750 GB
hard drive.  It is located under my helm seat and the LCD monitor cable
is run through the engine room to the dinette table.  The monitor sits
on the dash when underway.  I have a fairly bright NEC display that
works fine in the cabin.  I use the computer for everything.  My main
operating system is Ubuntu Linux with windows xp running in a virtual
machine and Coastal Explorer for navigating.  (Highly recommended,
Version two looks great.)  Never had a problem with the computer that
wasn't self inflicted.  I consider myself an expert with a computer,
been messing with them since 1966 so I am not afraid to use it for
multiple things.  I dual boot with windows xp to play games but don't do
much underway other than navigate and maybe check the weather on the
Internet.  (I have been known to mess around some on long boring watches
offshore.)  I find a wireless keyboard and mouse ideal for this kind of
setup.

Everything is run from a Magnum 2000 watt sine wave inverter.  I shut it
down when anchored because it draws about 15 to 20 amps from the battery
bank, if I need an anchor watch I have a small laptop that doesn't draw
much when plugged in.

I have never found a laptop with enough horsepower to run the
applications I use so a desktop works best for me.

Having said that, almost any laptop will run navigation software if
that's all you want to do.

Mike

Ron Dreher wrote:

Ron,

I used to use a Dell D620 laptop but found the display brightness to
be lacking even in the indirect sunlight I get in my pilothouse.

At home I use a Mac and at work I use Windows.

Recently, I acquired a new MacBook pro and put VMware Fusion on it. I
use 2 virtual machines running Windows, one for work and one dedicated
to running Coastal Explorer. So far, operations have been flawless and
the built in 300 nit display seems to do very well in all but direct
sunlight.

I am currently using a small inverter to power it while underway but
am looking at other options to condition the onboard 12v to eliminate
the inverter.

For gps, I tie into my raymarine gps as well as use a USB attached
Garmin.

For Internet, I use either an ATT air card or a high gain Hawking USB
attached WiFi unit depending on where I am.

All of the above works well with Mac OS X, Win2k and XP Pro.

This allows me to have a single system for all uses and enables me to
isolate my workloads.

I am very pleased so far.

rt

Randy Thompson
Soul Tender
Krogen 39

On Jan 14, 2009, at 8:43 PM, "Ron Dreher" RDreher@roadrunner.com
wrote:

Arild,

I've been wondering about this one for awhile...when a laptop is plugged
into 110V, is the system running off of that feed directly (after converting
it) or is it always running off of its battery system which is being
concurrently recharged from the 110V?

If the latter, does that provide adequate surge protection for shipboard
operation?

Bob Deering
Juneau, Alaska

On 1/14/09 8:29 PM, "2elnav@netbistro.com" 2elnav@netbistro.com wrote:

Robert, The power cord provides 110V which is stepped down to 19V and also charges the battery. The only time you are running off battery power is when you unplug the cord. There is really no surge protection on this cord. Chuck

To follow our adventures, go to

http://trawler-beach-house.blogspot.com/

http://sea-trek.blogspot.com/

Is that not exactly what I said? Regarding inverters, we did use a dedicated inverter for some time with our laptop but found it to be less energy efficient for this small load and actually used MORE from the batteries than the 12V to 19V power cord. Additionally the inverter interfered with the SSB radio and since we use the computer with Airmail and our Pactor modem to get weather information this was not acceptable and it was a pain to have to turn the inverter off every time we used the radio. As a marine electrician and certified electronics tech this stuff is not too newbie to me. Chuck

To follow our adventures, go to

http://trawler-beach-house.blogspot.com/

http://sea-trek.blogspot.com/

--- On Thu, 1/15/09, 2elnav@netbistro.com 2elnav@netbistro.com wrote:

Mike:  Doesn't the desktop rust immediately?  I have desktops at a beachside
house and they have rusted miserably.  Even my laptops have serious problems
when on a boat.  After about a week, they get so damp they don't boot up.
doesn't anyone else have this problem?

Jonathan

--- On Wed, 1/14/09, Michael michaelg@seadreamer.net wrote:
From: Michael michaelg@seadreamer.net
Subject: Re: T&T: On Board PCs
To: "Ron Dreher" RDreher@roadrunner.com, "T&T"
trawlers-and-trawlering@lists.samurai.com
Date: Wednesday, January 14, 2009, 11:54 PM

I use a home built desktop with a quad core AMD cpu 4GB ram and a 750 GB
hard drive.  It is located under my helm seat and the LCD monitor cable
is run through the engine room to the dinette table.  The monitor sits
on the dash when underway.  I have a fairly bright NEC display that
works fine in the cabin.  I use the computer for everything.  My main
operating system is Ubuntu Linux with windows xp running in a virtual
machine and Coastal Explorer for navigating.  (Highly recommended,
Version two looks great.)  Never had a problem with the computer that
wasn't self inflicted.  I consider myself an expert with a computer,
been messing with them since 1966 so I am not afraid to use it for
multiple things.  I dual boot with windows xp to play games but don't do
much underway other than navigate and maybe check the weather on the
Internet.  (I have been known to mess around some on long boring watches
offshore.)  I find a wireless keyboard and mouse ideal for this kind of
setup.

Everything is run from a Magnum 2000 watt sine wave inverter.  I shut it
down when anchored because it draws about 15 to 20 amps from the battery
bank, if I need an anchor watch I have a small laptop that doesn't draw
much when plugged in.

I have never found a laptop with enough horsepower to run the
applications I use so a desktop works best for me.

Having said that, almost any laptop will run navigation software if
that's all you want to do.

Mike

Ron Dreher wrote:

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Trawlers & Trawlering and T&T are trademarks of Water World
Productions. Unauthorized use is prohibited.

Mike:

Been using computers and other consumer electronics aboard for 20 years and
never had any of them rust or fail prematurely due to being aboard. Of
course they are protected from salt water spray. Are you using these on the
beach??

Frank Burrows    Destiny  1979  43'  Viking MY
Piney Narrows    Chesapeake Bay

At 07:34 PM 1/15/2009 -0800, you wrote:

If it were that damp I wouldn't like it much either.  I have never seen
any rust or corrosion on any computer I have ever owned.  As someone
said it is protected from spray inside a warm dry cabin.  I live aboard
and wouldn't be comfortable any other way.

Mike

Jonathan Haas wrote: