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Comment: Re:High Voltage DC more likely (Score 1) 582

by mirix (#49796547) Attached to: How Tesla Batteries Will Force Home Wiring To Go Low Voltage

Well, the reason datacenters use 48VDC is because that's what central offices used already, so the infrastructure was there, and they made hardware to fit.

The reason for that, though, is some combination of it being a high enough voltage to reach phones a few miles from the CO, without being so high that it would kill people. Now, why 48V instead of 50V... I guess is that it is an even number of lead acid cells (24, in this case). If you've ever been in a exchange, they've usually got the basement full of 48V batteries. (which is why the phone works when the power goes out).

Comment: Re:Why Low Voltage DC? (Score 1) 582

by mirix (#49796435) Attached to: How Tesla Batteries Will Force Home Wiring To Go Low Voltage

Universal motors have that name for a reason, they're brushed and comfortable with AC or DC. (things like hair driers, angle grinders, food processors, etc. If it's small and noisy as shit, it's probably a universal. Generally for short intermittent uses, as efficiency and life is poor). Induction motors won't work though, as they need AC.(eg. furnace fan motors, compressor motors in your fridge, etc).

Every LED light I've ever seen has a internal SMPS, it should likely be fine with DC. So will SMPS wallwarts (phone charger) and computer power supplies (well, in 230V countries, or ones with universal input. (older, mostly?) ones with 120/240 switch won't work, as it uses voltage doubler for primary voltage... which doesn't work on DC).

Comment: It reminds me of this quote from slightly later (Score 2) 387

by VAXcat (#49759791) Attached to: 25 Years Today - Windows 3.0
"And the Dark Lord made Orcs in mockery of Elves, and Trolls in mockery of Ents; and he made DOS in mockery of CP/M, and Windows in mockery of Macs, and NT in mockery of Netware; and he made Excel in mockery of VisiCalc, and Explorer in mockery of Navigator, and Word in mockery of WordPerfect; and he made MSNetwork in mockery of America Online; and on every side his foes fell reeling, defeated one by one as he crushed them by sheer weight of numbers, his hosts darkening the plain; and in the twilight years of the Second Millenium the Free Peoples of the West said, Lo, let us face this pestilence and destroy it, lest he turn all of Middle-Earth into a nest of foulness. And they forged the One OS, and they called it Copland; and they gathered their allies, the IBM Host and the Riders of Motorola, and they prepared for the final battle." Unfortunately, we lost the final battle, and the Darkness of Microsoft has swallowed up the land.

All constants are variables.

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