the usb 2.0 spec only mandates a minimum current of 500mA @ 5v, I dont think there is a maximum to what you can make available (subject to the thickness of the cables and associated safety considerations of a high-current connector).
By Anonymous JohnPosted Monday 29th June 2009 14:50 GMT
I've currently got three devices that charge by Mini-USB (Phone, ebook reader, and MP3 player).
What extra benefit does Micro-USB offer?
Charging is only slower if charging from a computer. If it's not enough, buy a charger with a USB socket. And the phone came with a lead that fits a car cigarette lighter socket.
By Ben TaskerPosted Monday 29th June 2009 14:52 GMT
Why would charging take longer? My phone can charge from a wall charger or a USB connection. The Wall charger is a lot faster than the USB connection, so why would micro-USB be any different?
Just because it has USB in the name, doesn't mean the phones will only accept USBesque voltages, most phones can now tell exactly what's been plugged into them
By SpectrokidPosted Monday 29th June 2009 14:58 GMT
the USB standard says what the MINIMUM amps are, and those are all you will get from your laptop, but if you use a power brick, you can pump amps til the plug melts..
By dr_forresterPosted Monday 29th June 2009 15:02 GMT
Motorola already uses a standard mini-USB SHAPED charger (as do Blackberry and HTC, they're intercompatible), but on the charger (or when using their program on your PC so you can charger that way), the two data lines are shorted together. Are they actually going to change to use a spec USB connection without any software having to be installed? Plus, I still can't get an answer on what that deliberately out-of-spec short will do to other devices I plug into their charger.
By John ThornPosted Monday 29th June 2009 16:22 GMT
It's all very well to talk (as on the radio this morning) about the tons of chargers being thrown away. But if this is to stop it means that at some point the phones' boxes will say "This phone doesn't come with a charger, use your old one". But that won't be 2011 because there won't be any old micro-usb chargers to re-use. So the earliest savings look like about 2015 to me.
By Anonymous CowardPosted Monday 29th June 2009 17:07 GMT
The reason for the short on the data lines is also the reason charging from pure USB is slower than with a mains charger - the USB specs limit the current draw to 500mA (although rarely enforced)... the short on the dedicated power supplies indicates that it's a dumb power supply and thus the power available is higher... thus the phone draws more power and charges quicker.
Also, is shouldn't affect other devices because the USB spec mandates a short on the data lines indicates a device has been plugged in. Devices shouldn't try to do anything clever until the device-induced short is acknowledged, which will never happen when the supply includes a short also.
By Stuart ArcherPosted Monday 29th June 2009 17:11 GMT
"This time it's a Memorandum of Understanding to use Micro-USB signed by Apple, LG, Motorola, NEC, Nokia, Qualcomm, RIM, Samsung, Sony Ericsson and Texas Instruments."
Look at the first one on the list.... I hate it when people comment on here without first reading the article properly!!
I've got a Blackberry 8700, and my wife has possessed various Motorola phones through the years. They both use micro-USB, but the motos won't charge with the BB charger - and the Blackberry charges like a raped ape on the moto chargers. It can go from next-to-dead to full charge in about 40 minutes, but takes three times as long with the original charger...
Presumably I'm running some kind of enormous risk that the phone will explode, but since it's never on my while I'm charging it, I figure it's a double bonus - new phone, plus I'll get mentioned in el Reg!
By dr_forresterPosted Monday 29th June 2009 18:05 GMT
So, a charger with the data lines shorted together will behave perfectly properly with other devices and not (my real concern) source more power than it can handle? I feel like I should know the second part, but I was always fuzzy in circuit theory, more of a software guy.
By Tim SchomerPosted Tuesday 30th June 2009 08:10 GMT
My Camera uses Micro USB, not for charging but for data transfer. I tried to get a spare data lead for it (so I could use it at work without having to remove the memory card every time) and I couldn't get one anywhere.
The sooner more micro USB leads etc are available, the better for me.
To answer the question of why micro USB not mini USB, has anyone else seen the size of micro USB? it's seriously thin so a natural for phones since they're getting thinner all the time.
The other question is will adaptors be available so those of us with older phones can use the new default micro USB chargers? (bit like the adaptors available for older Nokia chargers to fit the new smaller connector on the newer phones).
Sorry AC, but there are a number of errors in your post:
- the USB specs limit the current draw to 500mA (although rarely enforced)...
Rubbish i'm afraid, the 500mA is enforced by all computers, though for tolerancing reasons you will get away with 600mA most of the time.
- the short on the dedicated power supplies indicates that it's a dumb power supply
its a short across the D+ and D- lines, on the host (i.e. dedicated charger) end.
-Also, is shouldn't affect other devices because the USB spec mandates a short on the data lines indicates a device has been plugged in.
USB does no such thing, device attachment is signalled by a pull-down resistor on one of the data lines, they are never shorted together by a USB device.
- Devices shouldn't try to do anything clever until the device-induced short is acknowledged, which will never happen when the supply includes a short also.
like i say, USB would not release a spec that had this fundamental flaw, assume it works and that you don't understand it, rather than the opposite.
By Simon RockmanPosted Tuesday 30th June 2009 10:25 GMT
Motorola has had some phones with micro USB, there was a cheap version of the Pebble that used it.
There are however multiple micro-USB 'standards' and it might be hoping for too much common sense to assume that everyone is talking about the same one.
We can also assume that the vast majority of phones by volume, those price sensitive sub $50 phones will continue to use dumb chargers and barrel connectors.
I wonder who will jump on this band-wagon next and claim it as theirs?
By dr_forresterPosted Tuesday 30th June 2009 15:32 GMT
Read the story. The reason it's micro USB rather than mini USB (or just "use a USB spec plug to charge, people can get USB cables with the right plug) is because the Chinese mandated it first. Very few devices in the West currently use micro USB, so where do you think all these cables, converters, and adapters are going to be built?
Comments on: EU plays catch up on mobile single charger standard
About effing time too #
By Efros Posted Monday 29th June 2009 14:32 GMT
Enough carrot already... #
By VoodooTrucker Posted Monday 29th June 2009 14:38 GMT
why slow? #
By dave 37 Posted Monday 29th June 2009 14:48 GMT
Why? #
By Anonymous John Posted Monday 29th June 2009 14:50 GMT
LOnger charging times? #
By Ben Tasker Posted Monday 29th June 2009 14:52 GMT
no power limit #
By Spectrokid Posted Monday 29th June 2009 14:58 GMT
But... #
By dr_forrester Posted Monday 29th June 2009 15:02 GMT
OK then... #
By Mark 9 Posted Monday 29th June 2009 15:24 GMT
No Apple I see? #
By Anonymous Coward Posted Monday 29th June 2009 15:29 GMT
some relevant detail #
By kevin 3 Posted Monday 29th June 2009 16:22 GMT
What saving? #
By John Thorn Posted Monday 29th June 2009 16:22 GMT
@dr_forrester #
By Anonymous Coward Posted Monday 29th June 2009 17:07 GMT
@AC No Apple I See? #
By Stuart Archer Posted Monday 29th June 2009 17:11 GMT
Charging times #
By David W. Posted Monday 29th June 2009 17:28 GMT
@AC 29th June 17:07 #
By dr_forrester Posted Monday 29th June 2009 18:05 GMT
@Stuart Archer #
By Anonymous Coward Posted Monday 29th June 2009 21:58 GMT
Micro USB #
By Tim Schomer Posted Tuesday 30th June 2009 08:10 GMT
@ AC 17:07 #
By kevin 3 Posted Tuesday 30th June 2009 10:13 GMT
Micro USB in the wild #
By Simon Rockman Posted Tuesday 30th June 2009 10:25 GMT
Why Micro? #
By dr_forrester Posted Tuesday 30th June 2009 15:32 GMT
Good news #
By pctechxp Posted Wednesday 1st July 2009 17:06 GMT