When my family moved to Arizona in 1987 we brought along our Pontiac Firebird. My mom loved that car. But it melted in the summer heat. Literally the glue that adhered the the interior materials could not handle the heat and stuff just started falling down. Goop flowing down the walls and windows.
Starlink dishes go into “thermal shutdown” once they hit 122° Fahrenheit
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Re: Starlink dishes go into “thermal shutdown” once they hit 122° Fahrenheit
#202Earlier quoted context omitted.
Speaking of which, how could mobile phones be made to work in extremely hot temperatures for emergencies without shutting down?
It’s really just comes down to thermal mass vs. power dissipation. Either you have to increase the thermal mass, or limit the power. 99.99..% of use cases are for the phone to be in your pocket inside, so designing in a larger thermal mass, or limiting performance isn’t going to be a factor that drives design. However, since most phones are relative water resistant now, a good option is to use evaporative effects to…
I think the earth approach is a good option, even if one has to dig a few feet down to find some cooler ground in the middle of nowhere.
Re: Starlink dishes go into “thermal shutdown” once they hit 122° Fahrenheit
#203Earlier quoted context omitted.
Assuming you can keep something in the shade - does anywhere on Earth get to 140F beside inside forest fires, lightning bolts and volcanoes? There is a substantial portion of the worlds population that lives months at a time where temperatures are regularly well below freezing.
A satellite dish doesn't do super well in the shade :)
Depends on the shade: http://www.dishcamo.com/fabric_dish_cover.htm
Re: Starlink dishes go into “thermal shutdown” once they hit 122° Fahrenheit
#204Earlier quoted context omitted.
Speaking of which, how could mobile phones be made to work in extremely hot temperatures for emergencies without shutting down?
Mostly just by using better components and beter internal cooling (=thicker design). You can find same chips (=same function) made for consumer electronics, automative, aeronautic and military, all with different temperature and humidity ranges. I'm not sure about mobile phone CPUs/SoCs, but automotive equipment is a lot more resilient to voltage spikes well above the normal 12-14V.
Aerospace / military spec'd components would probably be the best way to go where possible. If it's a lithium ion battery issue, then maybe they should be using a different battery chemistry.
Re: Starlink dishes go into “thermal shutdown” once they hit 122° Fahrenheit
#205It should work at an extension of military temperature ranges for global use indoors, outdoors, and in odd semi-indoor scenarios like the back of a hot truck: -75 to +125 C / -103 F to 257 F. Treating it as retail consumer electronics shit isn't rugged enough for real use.
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Re: Starlink dishes go into “thermal shutdown” once they hit 122° Fahrenheit
#206Starlink is in beta. The entire purpose of the beta is to find stuff like this. They found something, and I'm sure that the next iteration of this before it goes to mass market will account for it. You're just seeing the system work.
If your engineering team had to wait for a product failure to realize an item that's going to be outdoors in the sun is going to get hot, what on earth else are they missing?
I doubt that everyone on the team missed the fact that electronics get hot outdoors in the summer. Rather, they probably chose to launch a product that breaks when it gets hot, because it's an easy problem to fix later. Now that something is out in the field, they can debug their network, satellites, RF hardware, installation instructions, management applications, and figure out what kind of customers want to buy this thing -- all in parallel while some tiny EE team redoes the BOM to use better-spec'd components. Everyone at the company now has a ton of work to do to produce the next version, taking into account real-world feedback as they do it. Would it be worth blocking all those projects another 3 months just so that some guy in Arizona gets more Internet uptime on the hottest day of the year? Probably not. It sucks to invest in an early product and have it break on you, but it's also probably not possible to have a company that releases a totally flawless product on day 1. If you demand perfection, what you are really demanding is for the product to never exist.
(It's also completely possible that the parts simply aren't available. You may have noticed that there's been a pandemic going on for the last year or so, and that's hurt the availability of many electronic components, among other things.)
Re: Starlink dishes go into “thermal shutdown” once they hit 122° Fahrenheit
#207Earlier quoted context omitted.
It's not trivial to do things at tens of gigahertz at a wide range of temperatures. They didn't engineer it this way because they didn't consider the existence of Arizona, Texas, and Southern California. The thermal limits exist because RF is absurdly difficult. Maybe in 30 years we'll have TCXOs and other RFICs that make it trivial. Right now it's not. tl;dr: Your phone doesn't have radios capable of talking on band…
It's not impossible either. Cheap brute force hack: Have a chip burn power to heat the chip up to a constant temperature. This was done in one of the early precision band-gap references. More expensive brute force hack: Stick a Peltier cooler on the thing, and servo to a well-controlled temperature. Communication equipment is critical to work for emergency use, and coincidentally, emergency use is when you're most li…
I design RF/Microwave hardware. The issue is the long term reliability, specifically the semiconductor lifetime drops drastically with temperature, not to mention the passive components. The temp cycling may be more of an issue, as I have seen antenna arrays pull themselves apart during accelerated lifetime testing. I shutdown all of my stuff at 80C.
Re: Starlink dishes go into “thermal shutdown” once they hit 122° Fahrenheit
#208Earlier quoted context omitted.
A good litmus test for good city location is whether or not melting objects/burns from touching objects is a daily concern
“Product is fine, it is human civilization that is broken”, huh?
Human civilization is absolutely broken.
We're great apes running on on 50,000 year old hardware trying to cope with things invented after we were born: https://www.ted.com/talks/ruby_wax_what_s_so_funny_about_men...
Re: Starlink dishes go into “thermal shutdown” once they hit 122° Fahrenheit
#209Earlier quoted context omitted.
They put a non-automotive grade LCD in Teslas. I assume because they thought they knew better. I suspect hubris is at play more than full-on incompetence.
Just curious, what are the differences between normal LCD's and automotive-grade LCD's?
One thing that was shocking to me when I looked this up myself is the temperature range of a car dashboard where the LCD is mounted. It can get ludicrously hot in the summer if the car is parked under the sun[1], like 80-90 C (180-200 F) hot.
[1] https://www.clickorlando.com/news/2019/09/26/heres-how-hot-t...
Re: Starlink dishes go into “thermal shutdown” once they hit 122° Fahrenheit
#210Earlier quoted context omitted.
Interesting. What phone operates at 0F? A few years ago I was in 15F conditions, the batteries in both my phone and my hiking partner's phone would not work at all. Going out briefly in 0F weather and pulling the phone out of the pocket of a warm jacket might be fine, but I'm doubtful a phone could continue to function when thoroughly cooled to 0F. If there's been a recent shift in phone technology, then I'd like to…
I’ve only had problems even well below 0F in Minnesota using old phones. It’s just battery chemistry, current capacity and voltage are depressed by low temps. Some phones aren’t engineered very well and regularly pull current near their battery’s capacity which is just poor design.
Of course 3/4 of the people responding to how cold can a phone get are from Minnesota. Lolol. Edit: I am also