Sorry this topic has been discussed in many forms before.
I need a computer for the boat which I am going to buy ( 45 to 50 ft
cruising sailboat). I initially considered a desktop but was scared off
by the power consumption.
Now I am considering a Laptop. I want to use it to run navigation and
other boat soft ware, but I also want to use it for e-mails and for web
surfing when I have access and also to watch DVD's and CD's, so I feel
I need a Pentium 4 with Windows XP.

There is a bewildering choice of brands. One way to narrow the choice
is again power consumption from the house batteries since the computer
will be on a lot.
I can get an inverter and then plug in the power supply to that. But
that route looses about 20% of the power.
The better option is to have a DC to DC converter like one that is used
to connect a Laptop to the cigarette lighter in a car. But how much
power does that consume?
Third choice, is there a brand of Laptop eg Toshiba or others which
accepts power stratight from the House battery, ie a voltage anywhere
between 10 and 15 volts?

Hi Rolf,

You'd better verify the real need for a fast processor. That way
choice isn't limited to laptop on 12 or desktop on 220/120.
Look at http://www.myelectronics.nl/index.html?lmd=38328.020081

Regards,
Len.
S/v Present

"Rolf" wrote:

I initially considered a desktop but was scared off
by the power consumption. Now I am considering a Laptop.

Rolf, I have been looking into this for quite some time. I can't say that
I've made all the best decisions, but I ended up with both a laptop and a
min-itx computer.

If power consumption is your primary concern, mini-itx is the way to go.
They are single board computers with a max processor speed of 1 gig,
actually I think the new ones may be up to 1.2 gig. Mine is a 900mhz and it
does every think you have mentioned quite adequately. I run Nobel Tec VNS
on it, watch movies and use MS Office. You can power supplies for them that
will take any voltage between 11 and 36 volts and wire it directly to your
12v system. You will still need a dc-dc converter/regulator for the
monitor, but they are available as well. Most 12v electronics cannot be run
directly from your 12v system, the voltages vary too much. Here are a few
sources:

Converters for most laptops and many monitors:
http://lindelectronics.com/

for itx stuff try http://www.logicsupply.com/

A neat little power calculator: Power Simulator
http://www.mini-box.com/core/media/m...32 e&_xt=.htm




If you go the laptop route, I would recommend a Pentium M Centrino system as
they use less power. Look for one of the new bright displays, HighBright
XBright etc.



"Rolf" wrote in message
oups.com...
Sorry this topic has been discussed in many forms before.
I need a computer for the boat which I am going to buy ( 45 to 50 ft
cruising sailboat). I initially considered a desktop but was scared off
by the power consumption.
Now I am considering a Laptop. I want to use it to run navigation and
other boat soft ware, but I also want to use it for e-mails and for web
surfing when I have access and also to watch DVD's and CD's, so I feel
I need a Pentium 4 with Windows XP.

There is a bewildering choice of brands. One way to narrow the choice
is again power consumption from the house batteries since the computer
will be on a lot.
I can get an inverter and then plug in the power supply to that. But
that route looses about 20% of the power.
The better option is to have a DC to DC converter like one that is used
to connect a Laptop to the cigarette lighter in a car. But how much
power does that consume?
Third choice, is there a brand of Laptop eg Toshiba or others which
accepts power stratight from the House battery, ie a voltage anywhere
between 10 and 15 volts?

Rolf wrote:
Sorry this topic has been discussed in many forms before.
I need a computer for the boat which I am going to buy ( 45 to 50 ft
cruising sailboat). I initially considered a desktop but was scared
off by the power consumption.
Now I am considering a Laptop. I want to use it to run navigation and
other boat soft ware, but I also want to use it for e-mails and for
web surfing when I have access and also to watch DVD's and CD's, so I
feel I need a Pentium 4 with Windows XP.

The Pentium 4 is not noted for power economy, a better bet would be the
Pentium M Centrino, since you will eventually be able to use Wi-Fi on the
boat. It consumes much less power than the P4 and is just as fast/powerful.

There is a bewildering choice of brands. One way to narrow the choice
is again power consumption from the house batteries since the computer
will be on a lot.
I can get an inverter and then plug in the power supply to that. But
that route looses about 20% of the power.
The better option is to have a DC to DC converter like one that is
used to connect a Laptop to the cigarette lighter in a car. But how
much power does that consume?

A friend of mine has just blown up an IBM Thinkpad by using a DC-DC
converter. We think he was getting "spikes" from the alternator, which the
converter could not handle, whereas an inverter plus the laptop's own power
supply would have easily coped with the extra voltage. This was an expensive
mistake on my part as I recommended the converter!

Third choice, is there a brand of Laptop eg Toshiba or others which
accepts power stratight from the House battery, ie a voltage anywhere
between 10 and 15 volts?

Not unless you go back about 10 years. All the old laptops used to be
runnable from DC 12 Volts. The latest ones require 19 volts (some even use
20 volts). Forget this one.

Either go for a mini-PC with separate TFT panel, or a Centrino-powered
laptop from Tosh, (A60), Thinkpad, (R40)or Compaq, (M700) powered by an
inverter (300 watt min.), and the laptop's own PSU.


Dennis.
Remove "nospam" from return address.


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.798 / Virus Database: 542 - Release Date: 18/11/2004

On 7 Dec 2004 22:23:02 -0800, "Rolf" wrote:

route looses about 20% of the power.
The better option is to have a DC to DC converter like one that is used
to connect a Laptop to the cigarette lighter in a car. But how much
power does that consume?
Third choice, is there a brand of Laptop eg Toshiba or others which
accepts power stratight from the House battery, ie a voltage anywhere
between 10 and 15 volts?

The laptops I have used on boats--NEC, HP, IBM, and Toshiba-- all had
cigar lighter cords with no transformer. I suspect all that was inside
the bulge was overvoltage protection.



Rodney Myrvaagnes NYC

Let's Put the XXX back in Xmas

See NG uk.comp.sys.laptops, posting "laptop in car-power options" it
contains an extremely technical insight into the dangers of running a laptop
from a cigar-lighter socket.


Dennis.

--
Remove "nospam" from return address.
"Rodney Myrvaagnes" wrote in message
...
On 7 Dec 2004 22:23:02 -0800, "Rolf" wrote:

route looses about 20% of the power.
The better option is to have a DC to DC converter like one that is used
to connect a Laptop to the cigarette lighter in a car. But how much
power does that consume?
Third choice, is there a brand of Laptop eg Toshiba or others which
accepts power stratight from the House battery, ie a voltage anywhere
between 10 and 15 volts?

The laptops I have used on boats--NEC, HP, IBM, and Toshiba-- all had
cigar lighter cords with no transformer. I suspect all that was inside
the bulge was overvoltage protection.



Rodney Myrvaagnes NYC

Let's Put the XXX back in Xmas


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.798 / Virus Database: 542 - Release Date: 18/11/2004

I used a DC-DC converter for several years without incident. It seemed
to be about 85% efficient. It eventually crapped out and a new one was
more then $100. I opted to run the computer off if the inverter after that.
No problems there either and it also seems to run about 85% rfficient
or better. All this was with a couple of Gateway laptops.

Doug
s/v Callista

"Rolf" wrote in message
oups.com...
Sorry this topic has been discussed in many forms before.
I need a computer for the boat which I am going to buy ( 45 to 50 ft
cruising sailboat). I initially considered a desktop but was scared off
by the power consumption.
Now I am considering a Laptop. I want to use it to run navigation and
other boat soft ware, but I also want to use it for e-mails and for web
surfing when I have access and also to watch DVD's and CD's, so I feel
I need a Pentium 4 with Windows XP.

There is a bewildering choice of brands. One way to narrow the choice
is again power consumption from the house batteries since the computer
will be on a lot.
I can get an inverter and then plug in the power supply to that. But
that route looses about 20% of the power.
The better option is to have a DC to DC converter like one that is used
to connect a Laptop to the cigarette lighter in a car. But how much
power does that consume?
Third choice, is there a brand of Laptop eg Toshiba or others which
accepts power stratight from the House battery, ie a voltage anywhere
between 10 and 15 volts?

Rodney Myrvaagnes wrote:

The laptops I have used on boats--NEC, HP, IBM, and Toshiba-- all had
cigar lighter cords with no transformer. I suspect all that was inside
the bulge was overvoltage protection.


Are you sure about that? I have run Toshibas, Compaqs, and Thinkpads
from with both OEM and after market "auto" adapters. All of those had
to increase the voltage above the nominal 12 volts.

The good ones produced a steady and stable higher output voltage while
on the cheaper ones the output went up and down with the input but
stayed above it.

Some newer laptops have pretty robust DC-DC inverters and may run off of
anything that is close to right. But I'm too thrifty to test that
theory though because I have had some laptops that quickly fried DC-DC
inverters on ripply DC or under/over voltages.

Jack

--
Jack Erbes in Ellsworth, Maine, USA - jacker at midmaine dot com

In article ,
Rodney Myrvaagnes wrote:

On 7 Dec 2004 22:23:02 -0800, "Rolf" wrote:

route looses about 20% of the power.
The better option is to have a DC to DC converter like one that is used
to connect a Laptop to the cigarette lighter in a car. But how much
power does that consume?
Third choice, is there a brand of Laptop eg Toshiba or others which
accepts power stratight from the House battery, ie a voltage anywhere
between 10 and 15 volts?

The laptops I have used on boats--NEC, HP, IBM, and Toshiba-- all had
cigar lighter cords with no transformer. I suspect all that was inside
the bulge was overvoltage protection.



Rodney Myrvaagnes NYC

Let's Put the XXX back in Xmas

Actually most of those have a power input voltage of higher than 12Vdc.
That bump in the line is a Dc/Dc conveter that boosts the voltage
up to the required input voltage.....



Me

On Thu, 09 Dec 2004 12:50:25 -0500, Jack Erbes
wrote:

Rodney Myrvaagnes wrote:

The laptops I have used on boats--NEC, HP, IBM, and Toshiba-- all had
cigar lighter cords with no transformer. I suspect all that was inside
the bulge was overvoltage protection.


Are you sure about that? I have run Toshibas, Compaqs, and Thinkpads
from with both OEM and after market "auto" adapters. All of those had
to increase the voltage above the nominal 12 volts.

The good ones produced a steady and stable higher output voltage while
on the cheaper ones the output went up and down with the input but
stayed above it.

Some newer laptops have pretty robust DC-DC inverters and may run off of
anything that is close to right. But I'm too thrifty to test that
theory though because I have had some laptops that quickly fried DC-DC
inverters on ripply DC or under/over voltages.

Jack
No, I didn't take them apart. I was guessing by the size of the bulge
in the cord.


The most recent of these machines is a 1995 Toshiba Libretto, the
THinkpad was a 701 "Butterfly" from ca 1989, the HP was a 386SX
machine, which must be ca 87, and the NEC was 84.

THe NEC I know didn't step up. It was just a cord. THe HP had its PS
internal. It used a conventional PC power cord and couldn't be used
with a lighter socket except with an inverter.

I doubt anyone is trying to use any of these on a boat now. The
Libretto still works fine, but places I could previously plug in a
modem now need Ethernet or wifi to call out, so it retires from boat
duty before spring.





Rodney Myrvaagnes NYC

Let's Put the XXX back in Xmas