Re: Things we remember...

In article
<499595fb-3edc-43ac-b75a-df6ac1e442ef@xxxxxxxxxxxxxxxxxxxxxxxxxx>,
Quadibloc <jsavard@xxxxxxxxx> wrote:

On Nov 7, 4:28 pm, Robert Carnegie <rja.carne...@xxxxxxxxxx> wrote:
lal_truckee wrote:

Has anybody yet pointed out that wired phones have their own power
source independent of the mains? A wired phone may still work for an
emergency in a catastrophic that takes down all the cell towers and
mains power.

Where does their power come from? I assume the mains in a nearby
neighbourhood.

The phone line provides power to telephones. Only if the phone line is
cut do phones that aren't plugged in to the wall socket not have
power.

But you are right that the power still comes, ultimately, from the
power for the city - the telephone company doesn't (normally) generate
its own power. So if there's a city-wide blackout, the phones might
not work. However, they may well have emergency generators. Keeping
telephone service working was taken very seriously back then - and
still is, unless you're getting your phone service from your Cable TV
provider.

John Savard

One of the signals on phone lines is called "battery" for a reason...

48 volt batteries, to be precise. And just as a side-note to nowhere,
they can be used (with a stick of carbon out of a dry cell) to make
decent welds on light metals.


It's gonna take a LOT more than just a power blackout to shut down the
phone system. Unless phone cables are damaged along with the power being
gone (a not-unlikely scenario, I'll grant) the phones (the ones that
don't need a wall-wart to do their thing) will keep on chuggin' along.

Landlines are battery powered, and every cell site I've had a close
enough look at to be able to recognize a gen-set, has had one sitting
there waiting to kick in if the mains die, complete with fuel to run for
days, perhaps weeks. You may only be able to get connected to someone on
the same network as you, or within a single tower's reach, depending on
how bad the landlines that connect the towers get hit, but unless they
get knocked down or literally drowned, the towers will almost certainly
have power and be functional for at least several days, if not weeks.
Meanwhile, the undamaged sections of landline phones will be doing their
best to cope, on battery power, and I'm sure for major switching hubs,
generator backup as needed.

Kinda like the FAA radar processing installations - I used to work for a
guy who worked in one of those. He gave me the nickel tour, and among
other neat things, I found out that at his installation, they don't
"switch to battery" or "switch to generator" when commercial power dies
- They're *ALWAYS* on battery - actually, a huge bank of batteries, with
a backup genny turning at idle in case mains goes down, and mains (or
the genny, in the event mains dies) both go directly to keeping the
batteries at peak charge. Which meant switchover time to backup power in
the event of a mains outage was zero.

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