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От alexander koryagin (2:5020/2140.2) к All

В ответ на Заголовок предыдущего сообщения в треде (Имя Автора)

Hi, All!

-----Beginning of the citation-----

ACROSS THE MIDWEST today, hundreds of schools and businesses are
closed, dozens of flights and trains have been canceled, and the
governors of Wisconsin, Illinois, and Michigan have declared
states of emergency as a bone-chilling, breath-taking Polar
Vortex bears down on the region. While I slept in Minneapolis,
overnight wind chills in the city topped - 50 degrees. With
temperatures like that, you can't stay outside for more than
five minutes without running the risk of frostbite.

As a native Midwesterner, I'm used to the annual assault of
winter weather on the human body, hairless and adapted over
millennia to indoor living as we are. Despite our
thermoregulatory shortcomings, we've managed to survive extreme
cold through technology-from insulating clothing to systems that
pump hot air and water around our homes.

But much of the tech that facilitates our connected modern lives
itself loses functionality as temperatures drop below freezing.
Batteries, screens, sensors, lightweight materials-the things
that power our modern mobile lifestyles-just don't work when it
gets this cold. Here's what to expect of your gear.

Think about all the gadgets that you regularly plug into a power
strip. It's a lot, right? Besides everyday items like a phone
and laptop, you might also have a fitness tracker, smart watch,
Bluetooth headphones, digital camera, e-reader, vape pen, drone,
or rechargeable bike lights, just to name a few. Most if not all
of them are powered by lithium-ion batteries, whose high energy
density and ability to handle both low and high currents have
made them the industry standard for personal electronics. But
those same properties become a problem as soon as temperatures
dive below 32 degrees F.

"Lithium-ion batteries suffer so badly in freezing temperatures
because they have very little internal resistance," says
Hanumant Singh, an electrical engineer at Northeastern
University who builds cold-weather robots for places like
Antarctica and Greenland. Less resistance means these batteries
generate less waste energy as heat (a good thing in more mild
climes). But the absence of waste heat also means they're more
vulnerable when temperatures plummet. The colder it gets, the
slower the metabolism of the chemical reaction inside the
battery. The battery drains faster as a result. If you've ever
been texting someone at a healthy-looking 25 percent charge only
to have your phone die mid-eggplant emoji two seconds later,
you're familiar with how steep the drop-off can be. "It's very
dramatic," says Singh. Carrying around a smartphone in any
weather colder than - 35 degrees F, he says, will kill it
completely in 5 minutes-right around the time frostbite would
strike the hand holding it.

Such deficiencies are particularly pronounced in devices like
smartphones, which are designed to sit mostly inactive for long
periods of time throughout the day. Their batteries never draw
enough current to heat themselves. But vehicles like drones and
electric cars, which demand very high power for shorter periods
of time, can generate enough warmth to keep the batteries going,
just at a greatly reduced level of performance. While cold
weather is a challenge for all electric vehicles, the small size
of electric scooters can make them especially vulnerable to
failures, as noted by several "juicer" forums on Reddit.
Companies like Lime monitor the performance of their fleets,
including battery life, but say they are not yet aware of any
trends coinciding with this week's plummeting temps.

The performance of individual products will of course vary based
on the manufacturer, battery model, and wear and tear on the
device. Apple suggests not operating its phones below 32 degrees
F. Amazon says the same for the Kindle. Fitbit, on the other
hand, recommends a minimum ambient operating temperature no
colder than 14 degrees F for its wellness wearables, which
should maintain better temperature control based on continuous
contact with your skin. But the same general rules apply to
anything that uses lithium-ion battery technology.

So if you have to venture out into the Polar Vortex, store your
phone as close to your body as possible, leave the wireless
headphones at home, and keep your time outside to under five
minutes. If you do freeze your device, don't plug it in cold.
Allow it to slowly come up to room temperature before you
recharge it. Failing to do so sets off a different, unwanted
chemical reaction that could damage the battery permanently.

Batteries fare the worst in cold weather, hands down. But a
close second are the LCD screens that illuminate our phones,
tablets, laptops, digital camera displays, smart watches, and
automobile GPS mapping and control systems. LCDs consist of a
layer of millions of multicolored pixels, each one controlled by
a separate transistor. When turned on, a zap of electricity
shocks a tiny, twisted up liquid crystal to attention. In its
altered structural shape, the crystal directs light through a
pair of polarizing filters and into the pixel, lighting up the
desired color. All together these millions of pixels produce all
the colors in an image.

But LCD technology gets sluggish when it gets too hot or too
cold. Liquid crystals work best in a Goldilocks temperature
range somewhere between 32 and 120 degrees F. The colder it
gets, the slower the response time from electrical signal to
pixel transition, which degrades the image, making it blurry.
Some fluids can make crystals functional all the way down into
the negative 60s, but most consumer LCD screens crap out around
40 below. "It's a chemistry that doesn't work well in the cold
for a completely different reason," says Singh, who has resorted
to smuggling a laptop inside his parka when he travels to drone
launches in the Arctic. He waits until the absolute last minute
to expose the machine to the environment and prays that it
doesn't die before his vehicle is in the ocean. "If we were
somehow hypothetically not battery-limited, the screen would be
the thing that would get us."

Then there are the tiny gyroscopes, oscilloscopes, oscillators,
and more: sensors that collect the information that tells us
where we're going, what time we need to get there, how many
steps we took, and how many calories we burned to do it. These
components track the orientation of a device and how fast it's
moving through space-crucial tasks for navigating, telling time,
and logging activity goals. These sensors' performance also
degrades when the temperatures go extreme.

The fancier the sensor, the wider its operating range. "Doing it
across a huge spectrum, say - 50 to 120 degrees F, is almost
impossible," says Singh. "But that means they're going to have
accuracy issues at these extreme cold temperatures." To keep
costs down, most consumer electronics employ more run-of-the-
mill devices.

Take digital watches, for example. Whether it's an Apple Watch
or a Garmin or a $10 cheap plastic number from Walmart, what
they all have in common is that if you flip them over, the
backside is metal. The oscillator inside any of those watches is
calibrated to 98.6 degrees Fahrenheit, and the metal heat plate
conducts the wearer's body temperature to keep the sensor in its
most accurate temperature range. Take it off and wave it around
a - 50 windchill and you might lose seconds if not minutes of
your day. Not ideal if accuracy's your jam, but perhaps that's
one way to race through the coldest day in recent history.

----- The end of the citation -----

Bye, All!
Alexander Koryagin
--- FIDOGATE 5.1.7ds
* Origin: Pushkin's BBS (2:5020/2140.2)

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