At 07:06 AM 10/3/2005, Ken - N9VV wrote:
F.Y.I. this announcement today from VIA
http://www.digitimes.com/news/a20051003PR200.html
Ken N9VV
Interesting..
small, rugged car PC (carputer) enclosure designed to work in harsh
enviroments such as dust and high temperatures.
Doesn't say whether the enclosure is actually sealed. And doesn't provide
any thermal management information (just what is the thermal resistance
from inside to outside?)
Having cooked a few laptops in a car application, stuff like this is
really, really important. I didn't understand until I checked and found
that the usual laptop specs give max environment temperature of 30C... they
assume you're using them in an office with people at a comfortable
temperature. BTW, it's tough to find these specs on most websites. On
Dell's for instance, you can find that the disk drives are spec'd to 55C,
the AC power adapter is speced to 40C.. both are specs not likely to be met
in a car in the summer. Note also that the "reference point" for
temperature measurement isn't always the ambient air temperature (on some
disk drives, it's the head/media interface..)
FWIW, the tightest component temp I've found is the battery... +35C max,
*during storage*. From Dell's FAQ: Notebook batteries, including those
stored in laptop systems, should maintain an Operational Storage
Temperature of 0° to 35°C (32° to 95°F).
Of course, statements like: "mounted on sillicone rubber shock-mounts. "
doesn't tell you much about what the actual vibration that will be seen by
your hardware is.
However, it's nice to see manufacturers at least starting to produce
inexpensive enclosures nominally intended for car applications.
James Lux, P.E.
Spacecraft Radio Frequency Subsystems Group
Flight Communications Systems Section
Jet Propulsion Laboratory, Mail Stop 161-213
4800 Oak Grove Drive
Pasadena CA 91109
tel: (818)354-2075
fax: (818)393-6875
