TWL: Re: Computers and boats
"Question: How well do desk top computers withstand spikes? "
You can get UPS devices from lots of places and they're getting pretty
cheap compared to what they used to be - here's a link to one on
Amazon:
My understanding is that most UPS systems will not work with Modified
Sign Wave (MSW)inverters. The pseudo sign wave patterns they create
trigger the protection circuits in the UPS. As a result, it never
passes inverter current through. I checked with all the big name UPS
manufacturers about two years ago and that was the situation then.
UPS would work well at dock. It may work with a generator???
Perhaps a small dedicated inverter hooked directly to the batteries
would be an answer. I am using a standard surge protector on my
computer. I turn the power off at the surge protector when not on board
and whenever I switch my AC circuits to/from inverter. I get my 110AV
power from the inverter 100% of the time that I am not docked for more
than a few days.
Jerry
KK48 Whaleback "Capella"
Putting on my Systems Engineering hat, it seams to me that this thread has
seriously departed from the KISS principle.
We have a battery bank/alternator running an inverter to power a UPS (a
battery charger, batteries and an inverter) to provide reliable AC power to
a Desk Top PC which converts it to DC power. Does this seam like the
simplest solution?
I've been down this road over and over at work. We configure computers for
challenging boat applications and are very sensitive to reliability, cost,
weight and power requirements.
We have tried Industrial Computers which are just ruggidized rack mounted
PCs. They use a lot more power than laptops, so they need more cooling air.
This air flow brings with it a lot of salt and corrosion problems, so we had
to go to conformal coated card$. We also installed a (200 lb) UPS to keep
the PC on every power drop-out.
Our more recent solution uses the PC/104 card format, which are 4" square
cards with stacking connectors. It has both an ISA and a PCI expansion bus,
so expansion capability is almost unlimited. They use very low power (our
886 Pentium III uses 9 watts at 650 MHz) and are available in extended
temperature ranges (-40C to +85C) so we can seal them in a box and eliminate
the cooling fans, conformal coating and corrosion problems. The sealed boxes
are available for $93. We use an extended input range power supply
(http://www.diamondsystems.com/products/jupitermm 7 V to 30 V input range
$200, although on 24 volt systems we use the HE104
http://www.diamondsystems.com/products/he104 which has an input range of
6-40 V and costs $349) that runs directly off boat batteries and powers all
the cards through the stacking connectors (very simple integration). We also
added a PC/104 UPS card (http://www.rtdusa.com/PC104/UM/power/ups25.htm $309
batteries not included) which can run the system for 20 minutes using 8 AA
NiCd batteries.
If you want a permanent PC installation for a boat, I know from experience
that the PC/104 solution is the most reliable, lowest power approach and
they are cheaper than a desktop PC after you add the UPS and inverter that
you need to make it run reliably on boat power. In a few years, I'll install
one in Portager and give you all a report on how it works.
I don't understand why everybody keeps ignoring this option.
Cheers;
Mike Schooley
Designing "Portager" a 36' trailerable trawler
On Sat, 2002-03-23 at 11:50, Mike Schooley wrote:
We configure computers for challenging boat applications
Mike:
Thanks for the very informative post! It has open up a realm of
possibilities for me. Got a link to your company's site?
I have always built my own intel-based PC's, and will want to build 2
for the Tamara B.
Do you know of any watertight cases which will accept standard
motherboards? Have you ever run accross a semiconductor cooling system
appropriate for ship-board pc use, obviating the need for air-cooling
within the case?
Got any links to "ruggadized" components and material manufactures?
I plan to use a couple of the Xantrex PROsine 1800W Inverters for
electronic AC power (Not just for PC's, but for all electronics), any
thoughts on "true sine-wave" Inverters?
I don't understand why everybody keeps ignoring this option.
Well, me for one never thought of it :-) And I should have!
In the navy we coated PC boards with a kind of clear sealer;
what was it called?? :-)
Bob
--
Kelly and Bob, soon to be living and cruising aboard the
m/v Tamara B. Cape Elizebeth Me. http://www.tamara-b.org
kelly@tamara-b.org bob@tamara-b.org
411 Walnut Street #1885 Green Cove Springs, FL. 32043
At 08:50 AM 3/23/2002 -0800, Mike Schooley wrote:>
If you want a permanent PC installation for a boat, I know from experience
that the PC/104 solution is the most reliable, lowest power approach and
they are cheaper than a desktop PC after you add the UPS and inverter that
you need to make it run reliably on boat power.
I don't understand why everybody keeps ignoring this option.
Probably because it isn't available at the local computer store and you
don't see a product review in PC Computer magazine.
I agree it sounds like the better solution.
However, if I as a typical consumer in Vancouver or whereever ) wanted to
get one, where do I go?
Firrst hurdel is locating the source, ( which you have now provided )
then I need to reassure myself that this website represents a reliable
vendor source who will help me if I run into any problems, and finally
there is the small matter of having it arrive at my door.
What will shipping cost be, who will deliver it and what happens if it
arrives in a non working condition.
Now what? Supposing that I do not have a computer engineer nearby what
do I do to determine what needs changing.
At least with consumer goods you can take it back to the store and get
another.
The better stores even have staff who can check it out and explain what if
anything I did wrong or what is plugged in the wrong way etc.
Cheers
Arild
Probably because it isn't available at the local computer store and you
don't see a product review in PC Computer magazine.
I agree it sounds like the better solution.
Arild
Just go down to Fleet Marine in Richmond or look up Ross Ballantyne
waterman@waterman.ca.
Richard
capnrich@cnw.com writes:
Just go down to Fleet Marine in Richmond or look up Ross Ballantyne
waterman@waterman.ca.
Richard
Richard:
Got a name/address like that for a poor Easterner (east of Toronto, about 44N, 79W) ?
George of Scaramouche1, Frenchman's Bay, Pickering, Ontario
Clear Krylon (sp) spray?
Ben
At 10:36 AM 3/23/02, Bob Richards wrote:
On Sat, 2002-03-23 at 11:50, Mike Schooley wrote:
nip
In the navy we coated PC boards with a kind of clear sealer;
what was it called?? :-)
Bob
mike reminisces:
In the navy we coated PC boards with a kind of clear sealer;
what was it called??
George adds his 2:
Heard of an Australian company called Lanotec, that has developed a spray consisting of lanolin dissolved in some easily evaporating solvent for that purpose.
Lanolin is sheep's wool fat, has extremely high dielectric strength and is nearly impervious to atmospheric or nautical reactants. Lanotec has a website....
George of Scaramouche, who protects all his boat's exposed metal parts above and below waterline with anhydrous lanolin (for years).
At 12:31 PM 3/23/2002 -0800, Richard wrote:
Just go down to Fleet Marine in Richmond or look up Ross Ballantyne
waterman@waterman.ca.
Richard
Does he sell the exact product that Mike Schooley is talking about?
It was my impression he sold Ocean PC's which is not the same thing.
Arild
Bob wrote, "Thanks for the very informative post! It has open up a realm of
possibilities for me. Got a link to your company's site?"
The company I work for is DRS www.drs.com. Our products are mostly for
military applications and are not available to the general public. We don't
do marine PC's for consumer use.
"<snip> Do you know of any watertight cases which will accept standard
motherboards? Have you ever run accross a semiconductor cooling system
appropriate for ship-board pc use, obviating the need for air-cooling
within the case?"
I don't know of watertight cases for standard motherboards because of the
heat problems. In airborne systems we use conductive cooled cards which have
air blown through channels build into the outside of the case. These systems
always run hotter and need extended temperature range card$ (not your
daddy's PC:-). The Navy uses liquid cooled computers which are very
expensive. We have looked at putting a liquid to air heat exchanger
(commonly and erroneously referred to as a radiator) inside a sealed
enclosure with a stirring fan but I haven't found any production source of
such a device yet. Solid state cooling devices are commonly called Peltier
coolers. There are companies that make these devices to cool overclocked
PC's such as http://www.digit-life.com/articles/peltiercoolers/. You can
think of Peltier coolers as a solid state refrigeration system. They move
heat from a one surface to another. In the PC the cold surface is attached
to the processor and the hot surface has a fan blowing on it. This does not
get the heat out of the enclosure, it just allows the processor to run at a
lower temperature than the everything else. If you put enough of these
devices on the outside of the PC enclosure you should be able to transfer
heat from the inside to the outside, but it wouldn't be very efficient. Then
you would need to figure out how to protect the Peltier coolers from the
environment. Maybe if you rewired them to run backwards and mounted them on
the inside, but again we depart from the KISS principle.
"Got any links to "ruggadized" components and material manufactures?"
Try http://www.pc104.org/cgi-bin/lookup_pc104.cgi?dbase=Tech&level=public
and/or http://www.controlled.com/pc104/
"I plan to use a couple of the Xantrex PROsine 1800W Inverters for
electronic AC power (Not just for PC's, but for all electronics), any
thoughts on "true sine-wave" Inverters?"
I think it is better to get a DC power supply. Most PC power supplies will
run on modified sine-wave inverters, but many UPS won't. If you going to
have a UPS you might as well use the boat battery bank as your UPS.
"In the navy we coated PC boards with a kind of clear sealer;
what was it called?? :-) "
I think you are referring to conformal coating.
Cheers;
Mike Schooley
Designing "Portager" a 36' trailerable trawler