Ok, but Forrest is using all industrial components that are rated to
-40C. Are you saying he should add a resistor just to pre-heat the SD slot?
...ok maybe you're on to something there. How about that Forrest? Would
a 10cent resistor and 2 minute pre-boot warmup eliminate any issue?
On 5/18/2015 10:37 PM, Mathew Howard wrote:
You could get around that by putting a heater on board to warm up the
components, like the epmp has.
On Mon, May 18, 2015 at 9:34 PM, Adam Moffett <dmmoff...@gmail.com
<mailto:dmmoff...@gmail.com>> wrote:
The danger you have to consider is a cold start, such as if the
power was off for awhile.
On 5/18/2015 10:32 PM, George Skorup wrote:
This winter was pretty cold. For about a week straight in the
middle of January and again in February, I had a few base units
reporting under 0F every night. And I know the outside air temp
was -20 to -25F. Obviously take the base unit's temp reading with
a grain of salt because it's clearly generating some internal
heat. I would bet inside the enclosures it was easily -15F. But I
think your -13F is probably OK.
On 5/18/2015 9:09 PM, Forrest Christian (List Account) wrote:
What is the lowest temperature that each of you would normally
expect to see in your enclosures?
The reason I'm asking is that I'm in the process of developing
up a few new products.
To date, all of the packetflux products are designed with
components rated -40 to +85C (I.E way cold to way hot). I'd
like to retain this rating, but I'm running into a minor snag:
For storage, I'm planning on integrating a SD card (probably
microSD) in a socket. I only need a GB or so, and SD card
memory is inexpensive at that range.
Unfortunately, all the reasonably priced SD cards are only rated
down to about -25C or -13F. which are about ~$3 in qty.
"Industrial temperature range" ones which are good down to
-40C/F are available but they add at least $30 to the cost for
non-name brand, and even more for known brands. When you're
talking about a $100 end-user price, a $30 1GB SD card seems
excessive - and probably isn't even possible if I want to meet
the $100 price with some margin.
So, I'm currently playing the 'what options do I have' game. I
hate to ship a product only rated down to -25C/-13F, but I know
for at least a large chunk of my customer base they never see
below this temperature, especially when you add a watt of power
dissipation in the case with the device. Which leads me back to
my original question: What's the lowest temperature most people
would expect to see inside their enclosures.
--
*Forrest Christian* /CEO//, PacketFlux Technologies, Inc./
Tel: 406-449-3345 | Address: 3577 Countryside Road, Helena, MT 59602
forre...@imach.com <mailto:forre...@imach.com> |
http://www.packetflux.com <http://www.packetflux.com/>
<http://www.linkedin.com/in/fwchristian>
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