If PG&E power fails, your system MUST disconnect from the grid to keep from electrocuting a repairman.
The system may be using the power grid as a voltage regulator. If it disconnects while the sun is shining, there might be a voltage surge that could damage operating equipment.
Check out . They have a Solar and Wind Power sub-forum under "Generators & Motors". There isn't much in that section, but there are a lot of people who understand generators. I've seen discussions in other sub-forums about solar systems and people wanting to sell power back to the electric company.
Actual shutdowns should never occur regardless of the weather. The temperatures at which shutdowns occur are very high compared to the ambient temperature. When you run thermal testing on a tablet in a temperature chamber there's actually very little difference in terms of the internal temperature profiles across the ambient temperature range. Internal temperatures depends almost entirely on how the system is cooled (forced air, passive air, heat pipes, etc.).
Agreed, but chamber testing classically doesn't also include the complexity of solar loading. YMMV to what degree you want to include this as 'weather', but it is certainly an environmental factor. IIRC, more insight can be found in AR 70-38: peak solar loading can add up to ~0.1W/cm^2 to an exposed device. Subsequent surface temperatures can be +25C greater than ambient, and IIRC, the "becomes intolerable to touch (5 seconds exposure)" threshold is +145F.
Since you cannot use a tablet under direct sunlight, solar loading is not all that relevant, though I suppose that a tablet could be on while not being used, and be left in direct sunlight.
In any case, since the iPad's specified upper temperature limit for ambient temperature is 95 degrees F, the question is whether it's shutting down below that. If not, then the lawsuit is groundless since it's operating within spec. It's not unreasonable for users to expect a tablet to operate at higher temperatures, but they should have checked the specs before buying it for outdoor use in hot climates.
SMS wrote in news:4c57b3e2$0$22096 $ snipped-for-privacy@news.sonic.net:
somewhere,
That's the problem. The system is NOT cooled! There are no big heat sinks on the chips. There are no cooling fans, which can be very tiny these days like a notebook uses. There is no heat pipe or through-the- case passive heat sink array. The most important feature is the GLITZ....Glossy, shiny, "exotic", sexy.....and HOT!
Crapple knew exactly what it was doing designing it. Notice the very low upper temperature limit, far below the normal summertime outside air temperature across the middle of the planet. There is no "headroom" for sitting out of the sun in a hot car, a trunk, a suitcase on the tarmac waiting for the plane to arrive, operation where mobile devices are used, OUTSIDE in the SUN! There is no warning label warning you to never use the device outside of an air conditioned room and it CERTAINLY wasn't mentioned in any sales brochure or advertising that it was going to overheat if you used it outside an air conditioned environment.
Put shortly, it sucks!
Let's keep making it thinner and thinner with no inside air space to let the heat even circulate around. Let's cram the HOT battery, whether charging or discharging right up against the hot, high speed ICs with no cooling, whatsoever. Later on, when it causes a problem, we'll tell everyone to f*ck off because WE ARE APPLE and WE ARE OMNIPOTENT! You should have read the horrible specs and noticed you can't use it outside an air conditioned room before you bought it.
The fanboiz will defend it to the death, just like always. Crapple can manufacture a $4000 toilet that doesn't flush and they'll buy it and won't complain, most all of them. They'll rationalize away the FACT they're being screwed, just like always.
Did I mention its thinner and shinier and glitzier than any competitors?
-hh wrote in news:cdef108d-a3ec-4eb1-a1e8- snipped-for-privacy@v15g2000yqe.googlegroups.com:
Maybe they figured because you can't watch the glossy screen outside in the sunlight, it wasn't necessary to calculate how much heat it was gonna get being used on the beach!
Maybe that's why they have the stupid mirror in front of the picture! It discourages them from trying to use it outside a darkened room!
Pendantically, only the screen needs to be shaded, so if one were to sit while facing into the sun, this would place the solar radiation on its back. However, the far more likely situation is as you suggest, which is the temporary "sit it down on the table in the sun" mode.
Precisely.
Agreed, and as I alluded to earlier, a familymember didn't have any problems with theirs in the Caribbean in April/May, with daily highs running ~88F over a continuous two week period ... and yet this class action was IIRC filed by some guy in **Northern** California. AFAIC, it is immediately evident that solar loading and the "sat it down to heat soak in the sun" was likely present, and this all reminds me of the Insert-Ethnic-Group-Here joke about their national space program which was going to send their Astronauts to the Sun...
Sorry to see you making a public display of your ignorance of Thermodynamics, Larry.
It seems that you're hung up on the concept of *active* cooling techniques with the basic concepts of heat transfer, which not only permit convection, but also conduction and radiation.
And I'm sure that you'll now provide proof that this 95F temperature limit is significantly different than what all other manufacturers currently do.
FYI, to get you started, here's a link from Dell:
Please note the statement of:
"Laptop batteries, including those stored in laptop systems, should maintain an Operational Storage Temperature of 0=B0 to 35=B0C (32=B0 to
95=B0F)."
And here's the Dell Studio laptop:
Gosh, it also says a max of 95F.
And Larry's citations of where other manufacturers of laptops, netbooks, etc, etc, provide the 'good example' warnings that he is asking for will be of course be forthcoming in his next post, so as to show that he's not unfairly criticizing just one company....right?
But wouldn't a design that minimizes (if not eliminates) an air gap be thus expected to improve heat transfer to the exterior metal case where it gets transported away?
But wouldn't "shiny" be indicative of a finish that is more inclined to reflect solar radiation, rather than absorb it?
Hmmm....maybe its time to go look up stuff like emissivity coefficients?
They do? Which ones? I've never had this kind of thermal issue with a cell phone or an Acer netbook even in pretty harsh conditions. The apologies here, starting with the "technical" nonsense posted by Steven, are a sorry commentary on Apple engineering.
I'm talking real world issues, not spec sheets with guaranteed safe operating ranges. Well-designed electronic devices will operate at much more than 95 degrees F.
there is *plenty* of room inside a desktop computer for one or more fans along with large heat sinks, yet this acer desktop specifies a maximum of 95 degrees fahrenheit (35 c) and 80% relative humidity.
that means that in a large part of the united states in the past few weeks, the computer could not be used at all. it was simply too hot and too humid.
the fact that there is inadequate cooling in a *desktop* is a sorry commentary on acer engineering, far more so than anything apple ever did.
now watch the bashers try to rationalize this one.
The apparent issue is radiant thermal absorption, not convection heating, with insufficient means to dump excess absorbed thermal energy, as when used in direct sunlight, not hot shade.
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