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 …
My power brick is rated at 340 watts. Only four of five USB ports to turn my GFX cards on.
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.
USB-powered printers and monitors (good ones, that is). Boom! Only one PSU under my desk.
What? I can't run my kettle off my laptop USB port!
What good is that?
I actually just dropped a PC off to a customer today. The board had a little feature I'd not noticed (which will go unused for them :( ). It's got a IPhone4 detector/driver and it ups the juice to give it a full power charge when plugged in to the usb!
That's a lot of current to be slinging around....
or perhaps i missed something?
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.
You missed the bit about the higher power versions delivering 12 and 20v as well as the standard 5?
Firewire supplied 30v unregulated DC. Sounds like another catch up for USB.
Yup, Firewire was an awesome standard that didn't catch on...
I would have bet a penny to the pound that they were going to use 48v befor reading the article. Very surprised.
48V doesn't make that much sense - everything in a PC is based on 12V at most, so sure there are benefits to higher voltage, but why yet another useless converter ?
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.
RTFA. The article provides the information, but you do have to actually read it..
To be fair, I did add all the stuff about power modes in a revision.
Sounds great apart from this: http://xkcd.com/927/
I didn't even need to open that to know which XKCD skit it was. :o)
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.
Except that didn't happen. Almost every phone now uses microUSB to charge, instead of a mess of ports we had before.
A standard USB 3 power input for devices sounds like a good move, just as it has been for Smart phones (in Europe anyway).
Having high power USB 3 output on a laptop though, sounds like a recipe for expensive motherboard failures.
True, but there are still several different types of microUSB. My work PDA, supplied in January, and S-E phone have a different port than LSOH's Lumia 800.
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.
> take the frequency to 1000Hz so the voltage can go higher without killing people.
What has frequency got to do with lethality? 230v can kill you as easily at 1kHz as it can at 0Hz, 50v is unlikely to kill you at either.
" or take the frequency to 1000Hz so the voltage can go higher without killing people."
I don't know where you got that theory from - first I've heard of it.
However, much higher is not considered safety extra-low voltage so would require completely different connectors and higher standards of insulation for anything using it.
Wasnt this one of the nasty tricks that Edison played, trying to convince people that AC power was dangerous and they should be buying his DC system? It's also to origin of the Electric Chair in the US (yup, lobbying by Edison).
It's not voltage, but current that kills you. As most static shocks are multiple 1000's of volts.
As characteristic impedance varies from person to person the voltage required also varies.
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 ...
'or take the frequency to 1000Hz'
Surely it's DC through a USB.
what you need, mate, is a desktop computer
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.
> It's not voltage, but current that kills you.
I know. It still doesn't, in general, make 1kHz more lethal than DC, for a given voltage. Unless your personal characteristic impedance is highly capacitive, I suppose. 0.1F might do it, at 50V/1kHz.
> People do not have a characteristic impedance. They are not transmission lines.
Oh, I don't know. Hold both arms out parallel, grab the live in the left hand and neutral in the right. You'd make a pretty good shorted ¼ wave at 100MHz...
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).
I think this is about USB3 with its extra contacts that can trigger higher voltages to be used. This is how the EeePad Transformer chargers work already
A usecase for USB. Now if they would only use a propper connector...
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?
"Yey! I have an ultrabook that weighs 2kg!"
"Boo! I have to carry a 5Kg PSU with me everywhere!"
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".
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.
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.
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.
Biting the hand that feeds IT © 1998–2017