

USB wall outlet - new standard for DC plugs? - jonnytran
http://store.fastmac.com/product_info.php?products_id=458

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JimmyL
Anyone know more details about this, and if it's been approved? My
understanding is that everything that's part of a home wiring system (like
this) needs to go through a bunch of test (UL, etc.) before it can legally be
installed in a house - and that seems like a lot of work for a small-ish
third-party accessory company to go though.

EDIT: Looks like it's not yet - from the ordering page, "This item is
currently waiting on final UL Approval. It is scheduled to begin shipping in
early 2010."

~~~
joubert
"before it can be legally installed"

Does that only count for wiring that is attached to a public grid?

E.g. if I have a homebrew energy system that doesn't touch a grid, am I free
to attach anything I want including such USB outlets?

~~~
izak30
The UL is a certification program, They can't really tell you what you
can/can't install in your own home. They can't even tell you what you
can/can't sell to someone else. The issue is that most distributors won't
buy/sell things w/o UL approval (for good reason). I'd most certainly guess
that the creators have had them in their home for some time.

When I worked in commercial electronics, it was very typical for engineers to
install development products in their home, long before UL approval.

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dmaz
Now we need a USB surge protector.

~~~
j_baker
...and a company like Monster to charge 10x what it costs to make the damn
protector because it's "better quality".

~~~
dmfdmf
But the connectors are plated in GOLD!

~~~
electromagnetic
Give me a 10ft gold cable, _then_ I'll believe it has anything more than a
negligible effect on impedance.

~~~
izak30
and gold connectors on both ends and gold pcbs and solder...

~~~
nick5768
My understanding (from memory of an electronics class a few years ago) is that
gold is used for the connectors because it resists oxidation better. Copper is
actually a better conductor of electricity.

~~~
izak30
For sure. corrosion just isn't a big problem for most consumer or home
electronics though. Where it is, it's a problem in more than just the
connectors, because most electronics aren't sealed. (it's especailly useless
if the connectors on the $100 board aren't protected... and the $3 cable is..)

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dnewcome
Only problem with this is that now mains wiring is going to be part of the
obsolescence cycle.

~~~
notauser
I remember seeing USB ports on cheap computers in '98 and you can still get
normal to mini adapters like [http://electronics.become.com/6ft-usbamini-b-
device-usba-to-...](http://electronics.become.com/6ft-usbamini-b-device-usba-
to-mini-b-2-0-compatible--compare-prices--c204735781) that fit in those slots.

I don't believe the power spec has changed in that time.

~~~
catch23
I thought they were bumping the power spec for usb 3.0?

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dmfdmf
Does anyone know if there are any plans or way to add universal DC to the
standard electrical system? It seems with all the electronic devices it is
wasteful to generate AC and then convert to DC in switching power supplies and
in wall-warts, etc. This plug device looks like it just puts the transform in
the wall so does nothing to solve the conversion losses. Would it be practical
to add a DC offset, say +5v to the AC sine wave to directly drive electronics
in the home? I'm not an EE so maybe the idea is crazy but I hope someone can
explain.

~~~
SpacemanSpiff
A DC offset would have the negative side effect of causing AC wall
transformers to saturate, redering them useless. Also, as far as I know it
would cause problems for many kinds of AC motors. True, you could bypass the
DC offset with a series capacitor, but then you would suffer efficiency losses
in larger appliances, in addition to added cost and complexity. The problem
with having +5V centrally regulated and then distributed throughout the house
is wiring resistance losses. Let's say you decide to use 16AWG wire, and have
a run of 100' to a hypothetical outlet (not uncommon in even a mid sized
house). that means your round trip length is 200'. Given the resistivity of
copper, the resistance of such a wire is 1.26Ω, and with .5A of current your
voltage drop would be .63V. Therefore, 5V would leave the distribution box,
and only 4.37V would be available at the outlet. Worse, Pin=5V _.5A=2.5W,
Pout=4.37V_.5A=2.19W. Efficiency of just the transmission system is 87%. You
can get a good power factor corrected switching converter that can do better
than this just plugging into the standard wall outlet.

~~~
dmfdmf
Thanks

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lutorm
Cool, but too bad that 5V is on the low side to run all electronics. It's
easier to downgrade 12V->5V than to step up, so I'd prefer if we make new
building wiring it be 12V.

~~~
pmjordan
While there's some truth to that, I'm not aware of a de-facto standard 12V
connector.

I guess SATA power could be interesting as it has 12V, 5V and 3.3V rails, but
I don't think it's designed to withstand as many plug cycles as USB.

Firewire can supply power at 12V, but that's not standardised, so no device
can rely on it.

Many devices use 12V, but they use a vast spectrum of different plugs and
sockets - many are coaxial power connectors of different shapes and sizes,
some are not. USB is a surprisingly good choice, as it's standardised at 5V
with a minimum of 100mA and the option to draw up to 500mA. It's also vastly
more popular than any other similar connector.

~~~
JshWright
I'd say the closest thing we have a 12v standard is the barrel plug used in a
car cigarette lighter port. Of course, that's a pretty ugly solution for an
outlet.

~~~
pmjordan
"Pretty ugly" is an understatement. I don't think I've seen a single plug
design that is less reliable.

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thorax
My favorite airport would be the first to start using these.

~~~
duskwuff
SJC has USB outlets in the terminal. Not quite as slick as this one, but eh.

~~~
pronoiac
I can verify that. Did you see these & wonder if they had data connections
ready to snare the unwary?

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asciilifeform
> the USB ports only draw power when something is physically connected to the
> port.

Am I mistaken that this is a physically impossible claim?

~~~
electromagnetic
Technically speaking yes it will draw power, all wiring draws power (the wires
develop capacitance, but there's also electrostatic leakages around the bare
connectors, but at 110/240V it's negligible, this is a concern around
10,000V+, with DC it likely has no electrostatic leakage, and very little
drain due to capacitance.

However, what I believe you're thinking about is the transformer required to
turn 110V->5V and yes you're correct. An old school transformer would drain a
few watts when inactive, however the current types of transformers used in
Wall->USB devices provide virtually no drain, perhaps less than a watt, so
will have no noticeable effect on your electricity bill.

Simply put, changing say 20 wall sockets in your house to one of these USB
devices will likely have less effect on your electricity bill than plugging in
a 7W night light and leaving it in.

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ejs
Could possibly be a waste of power depending on the design. If you replaced
all outlets with something like this that may have another transformer plus
the power regulation circuitry your outlets would be burning power 24/7 (not
just when you use it).

At least with an adapter you may only have one and unplug it when its not
needed.

~~~
mjgoins
from the page:

"Please also note that the USB ports only draw power when something is
physically connected to the port. We didn't want a vampire port that
continually sucks and wastes power when not in use so this was one of the
features on the top of our priority list during the design phase."

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NathanKP
Someone could probably make something like this themselves. Of course the
"non-vampire" energy saving technique would be slightly harder to implement,
but I don't see any other reason why this would be too hard to implement.

Of course without UL approval you might not be covered by fire insurance if
your house burned down....

~~~
dmvaldman
in fact, people already have, but the cost is about 10 bucks anyway!

[http://www.instructables.com/id/Outlets-of-the-Future-aka-
in...](http://www.instructables.com/id/Outlets-of-the-Future-aka-in-wall-USB-
Charger/)

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scooter53080
Something like this seems a little more flexible, assuming it works just as
well:

[http://www.amazon.com/Belkin-BZ103050vTVL-Surge-Protector-
Ch...](http://www.amazon.com/Belkin-BZ103050vTVL-Surge-Protector-
Charger/dp/B0017HF3XO/ref=sr_1_1?ie=UTF8&s=hi&qid=1260131000&sr=8-1)

~~~
ryanwaggoner
Umm...actually, this just replaces the little AC -> USB adapters that many
devices come with already. I'd rather have it integrated into the wall so I
don't have to worry about losing it.

Of course, I still have to remember the cord. I think wireless data _and_
power is the future.

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elblanco
All that and I still can't get a house built with 3 over 3 wall jacks instead
having to deal with 1 over 1 like everybody else.

Anybody who can't find enough wall outlets in their home, raise your hands!

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isarrentheg
I'd wait until it supports USB 3.0 at least; for now, I'll be content with a
simple adapter.

~~~
j_baker
What exactly does USB 3.0 have to do with charging? Will it not be backwards-
compatible with 2.0?

~~~
isarrentheg
Yes, but with 3.0 devices won't the outlet allow more power?

~~~
pronoiac
Er, yes: 50% more power is provided for unconfigured or suspended devices (150
mA up from 100 mA), and 80% more power is available for configured devices
(900 mA up from 500 mA). Via <http://www.everythingusb.com/superspeed-
usb.html#4>

~~~
duskwuff
I suspect that the outlet will give you more power than that anyway - the
amperage limits restrict what devices should expect to get, not what hubs may
provide them with.

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diN0bot
what are usb power ports used for? i mean, what devices use them, or is it
that devices should use them for some reason?

~~~
tb
Mobile phones and digital cameras etc often come with USB cables for charging.
The intent is that they be charged from the ports on a computer but there's no
reason they can't be charged directly from a socket. The exception is the
iPhone, some versions of which will not draw any current from the USB socket
until a handshake protocol with the PC is complete, and so they will not
charge from this kind of arrangement.

~~~
allenbrunson
my iPhone came with a little transformer that plugs into the wall for
charging. obviously there isn't going to be any handshaking there. i was under
the impression that all iPhones were like that. are you saying that some
aren't?

~~~
ssharp
My iPhone charges from the home adapter that came with the phone, of course. I
also have a 3rd party USB charger that I bought two or three years ago for my
iPod. It came with both a home adapter and car adapter. The car adapter will
charge my iPhone but the home adapter won't.

~~~
rufo
Your home adapter probably uses the old FireWire power pins, which the iPhone
3G can no longer charge from.

There is also a handshake, but that's separate and (as of the 3GS) only
displays a "product not designed for iPhone" warning - even if it displays the
warning, it still lets you use the device.

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dbreunig
But isn't this sipping power ALL DAY.

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d3vvnull
Or a new way to set a house on fire.

~~~
thaumaturgy
At 5v & 600mA? ...OK.

~~~
jws
I think perhaps he means when the "lowest bidder" electrolytic capacitor in
the AC/DC converter, with the 2000 hour specified life span (83 days)[1],
overheats, bursts, and shorts the AC wiring inside your wall.

Presumably you installed it in a proper outlet box (I like steel) and it will
be able to handle the energy released while waiting for the line's circuit
breaker to trip without reaching the ignition point of anything inside the
wall.

[1] Not that these people would use them, but you find them in a lot of gear.
Especially dramatic when their tops are close enough to a case or heatsink to
short when they burst.

