[ltp] [X41] USB connector with power supply

Javier (a.k.a AlBundy) linux-thinkpad@linux-thinkpad.org
Thu, 9 Feb 2006 21:13:03 +0100


On 2/9/06, Laurent Gilson <pumpkin@gmx.de> wrote:
> Hello,
>
> >> I own a X41 tablet and i'm asking what is that USB connector with powe=
r
> >> supply. I mean, how can i use that? Is there any cable to connect that
> >> little usb-like connector with, say, an external cd reader?
> >
> > It is a "Powered USB" connector:
> > You can attach both a normal USB connector, or a modified PoweredUSB
> > cable.
>
> So basicly it's a USB-Port with a bit more power ?
>
> The examples pages shows a barcodereader (these work very fine with
> standard USB and even PS/2-Keyboard) and a POS-printer. I find it a bit
> strange to power a ~50W POS-printer from a laptop. Seems like a IBM-only
> tech to me.
>
> Is there a downside ? Does the USB-par of the port work like a normal
> USB-2.0-port ?

A Powered USB is like 2 independent connectors, glued to compose one connec=
tor.
Both connectors are independents. Attached cables are independents
(although they are covered by a common plastic jacket, so it looks
like 1 cable).

In http://www.poweredusb.org/whatispusb.html, you can see "1-
Host-side PCB Connector" is the connector into laptop. The lower
"sub-connector" is like a normal USB one. The upper sub-connector is a
power connector, which gives 6 amperes.

Normal USB cables can be attached to the lower sub-connector. If the
device (barcodereader or any device powered from the laptop) requires
more power, it will include a special USB cable (see "2. Host-side
Cable-end Plug"), and it can only be connected to a "1- Host-side PCB
Connector".

IBM owns three patents related to PoweredUSB technology.
(http://www.poweredusb.org/ibmpatent.html), but I think there are a
few laptops/desktops non-IBM with this technology too.

See also: http://www.cyberdata.net/whatispusb.html