So Where’s My Low Voltage DC Wall Socket? • Hacker News Board

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

#11

Post by kevin_thibedeau » Mon, Dec 16, 2019, 4:36 PM UTC

Spooky23 wrote: post #5

rhinoceraptor wrote: post #4

It seems like USB A/C are going to be that. You can already buy outlets that have both mains and USB ports, there are even dual USB C outlets now, that can do 30 watts: https://www.amazon.com/dp/B07PTWG5DV

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

USB-A can support power delivery. The standard predates USB-C.

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

#12

Post by Johnny555 » Mon, Dec 16, 2019, 4:43 PM UTC

Spooky23 wrote: post #5

rhinoceraptor wrote: post #4

It seems like USB A/C are going to be that. You can already buy outlets that have both mains and USB ports, there are even dual USB C outlets now, that can do 30 watts: https://www.amazon.com/dp/B07PTWG5DV

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).

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

#13

Post by alexhutcheson » Mon, Dec 16, 2019, 4:43 PM UTC

Comments below the original post are great.

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

#14

Post by dspillett » Mon, Dec 16, 2019, 4:44 PM UTC

MaupitiBlue wrote: post #6

rhinoceraptor wrote: post #4

It seems like USB A/C are going to be that. You can already buy outlets that have both mains and USB ports, there are even dual USB C outlets now, that can do 30 watts: https://www.amazon.com/dp/B07PTWG5DV

I was going to link to that exact product. I put in the USB A one a few weeks ago and love it. When the iPhone 12 is released I’ll switch to USB C.

> When the iPhone 12 is released I’ll switch to USB C

Depending on what standards your existing ports support and what power input the iDevice can accept, you may find that a simple A->C adaptor will suffice. You may not get the fastest charge possible so in that case will want to move over sooner rather than later, but this may be an inexpensive (in terms of money and effort) stop-gap measure.

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

#15

Post by Danieru » Mon, Dec 16, 2019, 4:45 PM UTC

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…

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?

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

#16

Post by theandrewbailey » Mon, Dec 16, 2019, 4:47 PM UTC

> ...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'.

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

#17

Post by baybal2 » Mon, Dec 16, 2019, 4:47 PM UTC

The telecom industry has 48 volt as a de-facto standard, bur never came to a mechanical standard.

Thus you see daisy chains of mechanical adaptors in telecom closets.

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

#18

Post by ocdtrekkie » Mon, Dec 16, 2019, 4:50 PM UTC

jon-wood wrote: post #3

I don't get why they write off USB so quickly. It's small, it's reasonably convenient, and is almost ubiquitous already.

The article explains: USB A's power is too limited for a large percentage of household uses, and USB C is complicated and expensive, requiring digital circuitry to negotiate.

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

#19

Post by zwieback » Mon, Dec 16, 2019, 4:50 PM UTC

jon-wood wrote: post #3

I don't get why they write off USB so quickly. It's small, it's reasonably convenient, and is almost ubiquitous already.

The current USB standards are great for small devices but for anything that requires more power it would be good to have something beefier, something less than the roughly 1500W a standard AC outlet provides but more than the current 15W or 20W of the typical USB port. 5V is just too low and requires a lot of compromise on the device side. I'd probably start with 12V or 24V to keep the current lower. I think there are newer USB ideas to provide something of that sort: https://www.digikey.com/en/articles/techzone/2017/mar/design...

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

#20

Post by consp » Mon, Dec 16, 2019, 4:51 PM UTC

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.