On Mon, Sep 12, 2005 at 01:49:28PM +0200, Matthias Grimm wrote: > On Mon, 12 Sep 2005 11:04:25 +0200 > "Federico 'Pain' Pistono" <[EMAIL PROTECTED]> wrote: > > > For some reasons my 12" Powerbook does not provide enough energy to > > the USB device. > > > > I have an external hard-drive, 80 GB USB 2.0, that has two connecting > > cables. It usually works fine with just the connection cable on a > > desktop with a USB 2, but if you have only a USB 1 or you have a > > particular situation you can use the other cable as well, its purpose > > is solely to provide energy when needed. > > > > When I first used the powerbook on OSX it worked fine with just a > > cable, and the same with Linux. Now it's gradually getting worse, and > > I can't even transfer decently any file. I am sure thr USB 2 works and > > it's configured, since if I plug the energy cable into another > > computer and the connecting cable in my 12" it works fine, meaning > > that I just nedd to provide more energy from my USB ports. > > Be carefull with that. USB is specified for 5V/500mA = 2.5W per > Port/Hub. Most hard disks, even the 2.5" Laptop ones, use more power so > you may damage your laptop if you use an external hard drive without > external power supply. Read the datasheet of your hard drive carefully. > > Some time ago I replaced my internal hard drive with a bigger 40GB one. > This hard disk has a nominal power consumption of 2.5W (USB limits) but > needs 5W during power up sequence. I put the old one in an external USB > housing. This hard disk has 2.5W nominal power consumtion and also 2.5W > during power up sequence, but nevertheless I don't have the courage to > use it without external power supply at my PowerBook.
Hehe, i got a nice usb+firewire 2.5" housing which had 2 usb connectors, one for dat transfer, and the second plugged into the power adapter of the housing, so you get the 5W you need for that :) I am using it as firewire disk anyway though, so ... Friendly, Sven Luther -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
