[ltp] Cardbus USB2 card for Thinkpad X30

[trotter]

At 13:16 26/08/2009, you wrote:
>trotter wrote:
>>I was reading on another email group that you can add a USB2 port to old
>>laptops with a cardbus interface.
>>Since the x30 has only usb1 I was thinking of getting one.
>>However on the same email group user recommended that an interface with a
>>power brick was used as usb2 with some devices attached can burn out the
>>motherboard.
>
>I'm pretty sure this is a myth. Even if the cardbus socket doesn't 
>have a current limiter, the USB card should have. The USB standard 
>only requires that USB ports provide 500mA. Lots of ports are 
>limited to this, including: the motherboard ports on my PC, the 
>front panel on my PC, my USB hubs without the power adapters 
>attached, and my T23's docking station port.
>
>I have a USB to 2.5" IDE hard disk adapter which only has one USB 
>plug on it. 2.5" disks usually require up to 1A. Plugging this into 
>any of the above ports results in it just not getting enough power 
>to spin up. You can hear it trying, but the USB port is clearly 
>limiting it. However, my T23 (and other ThinkPads) will power it 
>fine from the rear ports. I have used it like this extensively and 
>no damage has occurred.
>
>The same thing happens with all my USB 2.0 cardbus cards. If the 
>power adapter isn't attached to it it will limit itself to 500mA and 
>the disk won't power up.
>
>>I have searched for a cardbus with a power adaptor bus i can not find one.
>>Has anyone come across them?
>
>*All* USB cardbus/pcmcia cards have a power socket. The only 
>difference is whether it has a mains transformer on the end, or a 
>USB plug. I personally find the USB plug much more useful as I can 
>then use it when mobile, and the USB 1.1 ports on my T23 can give it 
>all the power it needs.


Hmmm a cheap one from scan in the uk with a NEC chipset doesnt have a 
power socket or a powering usb port.

It just has 2 standard usb ports (male?)

Martin N


Owner of the bwfc yahoogroup and Co-Moderator of  MiniDisc and 
amithlonopen yahoo groups.