My power brick is rated at 340 watts. Only four of five USB ports to turn my GFX cards on.
The USB Promoter Group has a new ambition: using the ubiquitous connectivity standard to power your laptop while saving the planet eliminating the need for proprietary power bricks along the way. The general idea, as outlined in the newly-completed USB Power Delivery Specification, is to deliver up to 100 watts over USB. That …
Well duh, at 100W it won't power high-power devices. But having 100W on each port would allow you to power multiple higher-power devices connected via a hub.
My wife uses a netbook + keyboard + mouse + monitor + printer + occasional scanner + external DVD.
100W USB ports would mean eliminating power bricks and that would both be more convenient and more efficient.
I managed to lose a monitor PSU and got a bargain on a second monitor, so I run them off the internal PSU no problem. The cables are fairly thin, but 100w constantly at for example 12v would need a pretty decent cable so as not to get too warm if coiled away somewhere underneath dust/rug/cat. That rules PoundLand out. Upping the voltage beyond 12V would involve faffing around with PSU standards, a serious obstacle.
Are they upping the voltage? (sure hope it doesn't get accidentally applied to a non-compatible device)
If not, are they making a really beefy cord that can carry 20 amps? (that'll be awkward to handle, and more expensive to make)
This article fails to provide any information by which we could assess the practicality of their suggestion.
This being ubiquitous USB, this standard might actually penetrate your home. Regulation of phone chargers by the EU might also help.
Ideally, you won't even notice that you have all those compatible chargers and devices at home until holy Steve, Bill, or Linus write a stone tablet, memo, or blog on the One PSU to Replace Them All.
Merging a USB hub into a laptop power brick would suit me fine. I currently have power, USB and ethernet cables tied together so they don't tangle. External 2.5" disks eat two USB ports and 3.5" need their own brick. It would be tempting to put a USB/Ethernet converter on a laptop power/hub and reduce the number of cables down to 1.
I am surprised they did not go for 48V like PoE, or take the frequency to 1000Hz so the voltage can go higher without killing people.
People do not have a characteristic impedance. They are not transmission lines. People merely have a (very variable, depending on lots of conditions) impedance. And the reactive component is insignificant in most cases anyway.
And while it is technically correct that (in most cases) it's the current that kills you, it is extremely unlikely that voltages below a certain level will result in enough current to be lethal. Therefore, only voltages above this level (generally set at 48 V) are considered dangerous.
This post has been deleted by its author
This is one of Tesla's tricks -- HV running at several kHz can travel through the body without the body feeling pain: at a high enough frequency, the electricty is only skin deep (literally) as it can't penetrate further.
One problem with this though is the body's nervous system doesn't respond quickly enough ... so even if it *should* hurt, it won't. So you can get burns, but it won't necessarialy kill you.
So I wouldn't call it "safe", and by virtue of its effects on the body, it may even be more dangerous because you won't immediately feel the effects. At least at 50Hz it's enough to make you notice when you've touched it ...
This post has been deleted by its author
Because you know for certain each USB3 PDS-powered device will come with a PSU at the very lowest profile it can possibly run on. (Also, PSUs are quite inefficient when run at the low end of their rated output.)
That said, Profile 1 (5V, 2.0A) is already in existence, most tablet chargers are rated at that.
The new bits here are the 12VDC and 20VDC ratings - do these higher voltages need to be negotiated between PSU and device (expensive), or do you need a cable with even more cores like they did for USB3 in the first place (expensive)?
More importantly, it won't do anything about the myriad of utterly shit "USB chargers" out there that claim 1A or more and not delivering anywhere near that, or even exploding because they don't meet any of the creepage clearance and insulation requirements. Take a look at this one.
(I really hope that's a clone and not a genuine Apple. Possible story for El Reg?)
I know it's not the USB Promotor Group's direct legal remit, but it is already incredibly difficult to buy a legitimate USB charger and I see this making it worse. Somebody needs to start stamping on the charlatans (and Amazon don't appear to care, I've seen so many from their 'partners' being left up after a multitude of "it exploded on me" reports).
Now instead of trying to figure out where the hell my wife has left my phone charger every time she misplaces her own, I'll also have to figure out where she left my laptop charger?
Maybe if there were some central way of delivering power at a reasonable voltage (let's say 45-50V) without getting carried away on the current, where you could just draw DC out of the wall and save all this tedious mucking about with finding chargers. Something like PoE, but maybe about the same?
NEWS - vendor ups numbers, creates solution looking for problem.
well when I plug it in at home it works...
I cant wait till we have to upgrade all the portable devices with micro-usb on them just so fwit in finance can plug in his incredibly stylish but audibly crap speaker dock anywhere on a whim.
Can you get car batteries with rounded corners?
You already have a heavy power brick with your ultrabook - have a look under the desk. With USB charging it should be capable to make it much smaller and you may have many places where you don't even need to bring power with you as you'd just be able to plug in to a universal USB charging socket. There's no reason why chargers would have to become bigger.
I'm sorry? If you take a 5W USB charger and make it a 100W charger it doesn't have to be any bigger, because it's USB? Surely a 100W charger is the size it needs to be to convert 100W at mains voltage to 100W at 20V? Putting a USB socket on a 100W charger will not "make it much smaller".
Who said anything about making a 5W USB charger smaller - this is about making a standard power brick that is already pushing out the required Power to run the Ultrabook smaller. With standardisation and reference designs you can expect better quality and more efficient transformers.
You also might have the ability to use existing charging sockets, or share devices amongst a power hub, hence making it only necessary to carry the relevant cable - and therefore much smaller.
Typical laptop/ultrabook PSU is about 100w, (yes some are bigger, some are smaller), if the psu needs to also supply 100w * Number of USB socket + Laptop requirements.
Your PSU is going to be 200w minimum!
The voltage isn't going to change so current needs to double, more current = thicker wires and heavier duty and/or more components = much more weight.
My 1 Amp phone charger gets too hot to hold here (it is charging a less-than-economical Galaxy note, mind you).
What would 5 Amps per port feel like in an even smaller and more enclosed form factor?
And if it can drive 5 Amps as a charging service, won't we overheat the batteries too? (back to the galaxy - my 3030 mAh battery can hit 50'c easily while charging at room temperature).
While such technology sounds good, I think the "human factor" has been overlooked slightly.
Having a 5amp PSU doesn't mean to say it's going to run at 5amps when you connect it to your battery.
It's going to depend on what the internal resistance of the battery is at the time and no there will be protection circuitry to either limit (or regulate) the current and if fast charging a battery, a temperature sensor attached to the battery to prevent it getting too hot (and presumably exploding).
Your 1 amp phone charge is probably also a p**s poor design, probably sourced from China and inefficient in power conversion from input to output, with the resultant heat that is generated.
When will office desks be produced with built in power distribution of this type? Why do we still need power bricks for everything? Yes, this standard will allow us to remove some. But I'm betting the laptop charging still requires a brick.
Every office desk has a monitor, mostly now flat panel with a brick. Why not centrally power a bank of desks with one 20v brick?
Let's take it one step further - instead of just "cumputer" stuff with USB being powered, let's set a world standard for low powered devices. Aim to have a new voltage/amperage (power) combination available in every home, office, hotel, etc in the world. How many travellers take something that doesn't require a power brick (the hair straighteners being the obvious exception). Most devices need the power brick and a plug converter. If we can set a universal standard then we all benefit.
This won't happen overnight. And I know some pessimistic commentards will point out flaws. This is a high level suggestion to get us started. They said it wouldn't work trying to get mobile phones onto a standard charger socket, but that's getting there, and over time the obsolete ones disappear..
Two words: Voltage drop.
As a former looser of the juice, one thing we had to take into consideration for long runs was voltage drop. The longer the run, and the higher the current the more voltage drop was a problem. One way to reduce voltage drop, was to increase voltage. In the US (where I live) typical 3 phase power is either 120/208 volt Wye or 124/240 volt Delta. Raising the voltage to 277/480 volts Wye cuts the current needed down by half or more. Since the current flow in a circuit is a component of the voltage drop, cutting the current affects the amount of drop. It is one reason why long distance transmission lines are truly high voltage (72kV, 144kV, 230kV or 460kV). You are not going to move hundreds of mega watts at 120 or 240 volts without severe voltage drops.
Now, a single 48V DC desktop distribution "brick" with short (less than 6 feet) cords is a different matter. And quite feasible.
If all you need for each device is an amp or two at 48V, Power over Ethernet does it today, and so does your existing LAN cabling (hopefully). A power injector at the network centre end, and either a PoE device or a tiny DC->DC adapter at the device end. Job done.
Everything from printers to TVs comes with a LAN connector these days. Another few cents of chippery and you can put power in through it, AND there'd never ever be a need for manufacturers or distributors to supply a country-specific power supply with the device (a country-specific PoE injector would do when there wasn't one already available at customer site).
Why this hasn't caught on, I really dinnae know.
I think we can all agree that power bricks are a right royal PITA.
This proposal is constrained because it comes from the USB Promoter Group, within that constraint it's OK, maybe - others can argue the nitty gritty.
I'd like to see a solution that has the same ubiquity as mains power so that carrying a brick becomes pointless, ideally the outlet would then be built in to the mains socket itself - and you just plug in. Thus the source of power is not a USB socket (it's special*) - the consuming socket is ... well whatever you want USB, phono etc.
Of course this is so much fairy dust and USB has all the traction.
I've seen a few USB power supply modules for UK wallplates, so you can get them already.
About £20 IIRC.
This would have the possibility of making them a lot more useful - I can see monitor, printer and netbook manufacturers jumping on this, as 'generic' PSUs are much cheaper than branding your own.
48V and more PoE would be nice. I wonder which direction monitors will support this in - or will they support both? Having my laptop charge down the monitor cable would be nice (more or less what Apple do with the Thunderbolt displays: displayport+magsafe), but so would having the monitor powered from the desktop rather than needing its own power cord (like Apple used to with some of the G5 towers I think?).
5A at 20V should be enough for a lot of things - laptop charging, some printers, scanners, any kind of external storage, decent USB hubs without needing a power brick or being limited to self-powered devices only. The combined laptop-charger+USB-hub route sounds good to me: I could have one at home, one at work, connect the power supply in to the network, printer etc and just have a single cable to handle.
A long time ago, many PSUs did exactly what you're talking about for G5 towers.
It was not powered from the desktop PSU, simply just wired to the PSU in -
This wasn't such a good idea either, considering the power cable requirements that would vary wildly with a PSU burning from 100 to 700 watts and more, and a screen that could also do the same, depending on your pick.
20V is bad because it implies yet another power converter to bring it back to 12V - if you want to go above 12V, be at least smart enough to use a multiple for future simplicity of build.
...when he pointed out that we don't need a new standard to solve this problem - we just need to start using the one we've already got : The 'lighter' socket found in cars. 12V, enough amps to heat metal to the point it glows.
So, just as the socket on the mains side of the power brick is (mostly) standardised on a kettle-style plug the hardwired cable on the laptop side could be replaced by a car-style socket.
True this means carrying slightly more than standardising the socket on the laptop - you still need a cable between the brick and the laptop. However a cable is a lot lighter than the power brick, plus if you're travelling by car for some of your journey you can charge up the laptop on the way without carrying anything extra.
Are you daft???
Unless you are talking about AC; because if not, then you have forgotten about one aspect to DC - polarity.
I can remember having to get one of those dammed Radio Shack co-axial adapter sets, different diameter pins. different outer diameters, etc. What a PITA!!!!!
Then what is the voltage the dammed thing runs on? How much current does it "eat"? You certainly do not want to run a device that requires 2.5A from a power adapter that can only supply 0.5A, now do you??
Icon says it all.
>What a PITA!!!!!
True, no such worries about USB. We don't have mini/micro/fullsize A, B fitting there, do we? And we'll not need any new adapters to handle 5A USB either.
> You certainly do not want to run a device that requires 2.5A from a power adapter that can only supply 0.5A, now do you??
0.5A, like a standard USB port? No, you're right. I'd want to be sure that I was using one of these new USB adaptors that could deliver 5A. I do hope they don't use the same connectors as the 0.5A ones.
Stupid idea. USB was never designed for carrying power, leave it well alone. The connector format is totally naff anyway, it's too symmetrical, often you have to look at the connector to ensure you can plug it in.
What happens when someone takes a 100W power supply terminated in a power USB connector and inadvertently plugs that into a standard 5V peripheral USB connector on say a laptop..BOOM..bye bye £600 laptop. Naff idea,.
Over the years, there has been discussion in the IEEE* Product Safety and Electromagnetic Compatibility mailing list concerning the need to keep USB ports at SELV; "safety extra low voltage." This means not only a safe, low voltage, but a safe, low current as well, and doing so makes possible some quite inexpensive, very small cables and USB devices.
It will be interesting to see new what practices in board and device design are needed to accommodate this use: Engineers know that when seeking to make something both good, quick, and cheap, it is inevitable that one of the three must be given up to have the others.
Tech warning because a lot of really smart people have forgotten High School physics.
Biting the hand that feeds IT © 1998–2022