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So Where’s My Low Voltage DC Wall Socket?

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Re: So Where’s My Low Voltage DC Wall Socket?

#31

Post by lostlogin »

Johnny555 wrote: post #12
Spooky23 wrote: post #5

Earlier quoted context omitted.

The author makes the valid point that USB-A is too low power, and USB-C requires active cables. (Translation: expensive or dangerous)

If you want one port that can charge multiple devices of varying needs safely, you need smarter cables. Sounds like a reasonable tradeoff. Otherwise every single cable would have to be built to handle the highest possible power delivery rate (100W for USB-C).

Looking at that plug and how chunky the holes are for ac power, when access is limited and you can’t see, shoving a usb c plug into the ac hole is going to happen often.

Re: So Where’s My Low Voltage DC Wall Socket?

#32

Post by secabeen »

allovernow wrote: post #23
ethagknight wrote: post #10

Is "Digital Electricity" a real thing? Its billed as an alternative to AC or DC. This may be as good a place as any to ask this question, but I am a hotel developer, and we've had a few people reaching out to us trying to sell "digital electricity" that sends high voltage over cat5 (up to 2000w per the Belden materials) by essentially sending high voltage for very brief blips with the ability to switch off before any…

Looks like buzzword marketing bullshit to me. Apparently they're just sending pulsed DC power over Ethernet cables? Nothing else in that article is as new or exciting as they dressed it up to be. GFCI outlets are standard in modern houses, they claim to be safely transmitting "high voltage" but 120V is not, and the "digital" buzzword stinks of marketing. >It transfers high levels of power over non-power cable You can…

You can get 100W over Cat5 with 802.3bt, but I can't tell if there are any special requirements for that cabling: https://en.wikipedia.org/wiki/Power_over_Ethernet#Standard_i...

Re: So Where’s My Low Voltage DC Wall Socket?

#33

Post by JoeAltmaier »

aivisol wrote: post #30
forgotmypwd123 wrote: post #9

I always thought running low-voltage DC through a house from a single supply was doomed due to voltage drop over the distances required....

That absolutely is. You could be better with 48 or even 24 volts, but then you are out of luck if you want to power a majority of devices which are 12v. So your only option is to go for USB-A wall socket which essentially is a wall-wart hidden in your wall. I do not see a good solution here.

A buck convertor in the socket (cost: $1) with a voltage dial or selector would do the trick.

Re: So Where’s My Low Voltage DC Wall Socket?

#34

Post by lostlogin »

More than a low voltage plug (which I’d love) is the need for in wall smart plugs that have a wired connection rather than wifi. I can’t believe I’m the only person that wants this and while I’ve found a few in wall smart plugs, I’ve never found a wired one.

Re: So Where’s My Low Voltage DC Wall Socket?

#35

Post by jacquesm »

gmueckl wrote: post #24
Danieru wrote: post #15

Earlier quoted context omitted.

Oh wow, I would not want 2000w going through Ethernet. Both for the obvious electrical issues, and for the dangerous mixing of safe sockets and hot sockets. No idea how this would be more efficient. Bursting voltage will lead to higher loses versus a continuous voltage. Are they claiming efficiency thanks to a centralized AC->DC converter?

Cat5 doesn't imply RJ45, so that confusion could be easily averted if people with brains developed that stuff. 2000w constant power transmission on a Cat5 sounds dubious, though. I don't know at what the voltage such a cable gives in and shorts wires. It would have to be pretty high to get the current to something the wire crossection can handle.

It's not the wattage that is going the be the problem, but either the high current or the high voltage (arcing).

Re: So Where’s My Low Voltage DC Wall Socket?

#37

Post by Jamwinner »

consp wrote: post #20
theandrewbailey wrote: post #16

> ...and incorporate a fuse to protect the appliance cable from fire. Those British BS1363, fused-mains-plug habits die hard. Lots of car barrel connectors have fuses inside. I'm not seeing much reasoning behind not using the car barrel connectors, aside from 'it was designed for cars, not as a general purpose connector'.

They break easily. Spring loaded bits (actual springs). No properly defined standard and they vary a lot. Come out easily depending on quality. Easy to contact center pole to side poles on insertion. No ability to add earth.

12v plugs are indeed a standard, and can be quite robust. Other than size and cost, there are no such downsides. On DC there is seldom an 'earth', gound is analougous to dc negative/neutral depending on local standard.

ANSI/SAE J563 and UL2089

https://en.m.wikipedia.org/wiki/Cigarette_lighter_receptacle shows the UL standard.

Re: So Where’s My Low Voltage DC Wall Socket?

#38

Post by unilynx »

If none of the current plugs are usable, can we have a low-power plug standard based on PoE?

Having both ethernet and low power from one socket would be perfect for IoT devices, save people from having to run Ethernet wiring themselves afterwards, and cut down on wireless spectrum use.

And your 'smart fridge' would just plug into both outlets and use a relay to cut 230V if the motor doesn't need to run.

Re: So Where’s My Low Voltage DC Wall Socket?

#39

Post by jessaustin »

consp wrote: post #20
theandrewbailey wrote: post #16

> ...and incorporate a fuse to protect the appliance cable from fire. Those British BS1363, fused-mains-plug habits die hard. Lots of car barrel connectors have fuses inside. I'm not seeing much reasoning behind not using the car barrel connectors, aside from 'it was designed for cars, not as a general purpose connector'.

They break easily. Spring loaded bits (actual springs). No properly defined standard and they vary a lot. Come out easily depending on quality. Easy to contact center pole to side poles on insertion. No ability to add earth.

I agree that these connectors are typically low-quality. I can't imagine ever needing to earth them, however.

Re: So Where’s My Low Voltage DC Wall Socket?

#40

Post by gwbas1c »

alexhutcheson wrote: post #7

Interesting idea, but running an extra set of cables is a non-starter. The cost/benefit analysis would never make sense for existing structures, and newly built structures wouldn't do it unless it was almost certain to become a universal standard. This is a classic chicken-and-egg problem. You would also still need something similar to a wall-wart to step down the voltage to whatever your device actually uses (e.g. f…

Also, the biggest non-starter is just how inefficient it is to move 12v any reasonable length. 12v domestic wiring only makes sense in very tiny small dwellings. (Think studio apartment or 3rd world country shack.)

Otherwise the voltage sag and resistance makes it cheaper and more efficient to do normal 120/240 voltage with device-specific converters. (For example, if I had to run 0-gauge cable from my breaker box throughout my house to support 12v, the cost of copper alone would be prohibitive.)

I honestly think standardizing on USB for devices that can use it is the best approach, given that we already have tiny AC->USB converters that don't block other plugs, and outlets with USB built-in are on the market. Furthermore, I wonder just how much we can shrink the typical wall-wart so it won't cover other plugs?

(I also think we're better off trying to do a global domestic 200 or 400 volt DC standard.)

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