Re: usb hard drive how?

Hactar (ebenZEROONE@xxxxxxxxxxx) writes:
In article <ff1d2c$1j$1@xxxxxxxxxxxxxx>,
Michael Black <et472@xxxxxxxxxxxxxxxxxxx> wrote:
Leo Bing Whiteway (leobingw@xxxxxxxxx) writes:
I was given a 10 gig USB hard drive. It has a jack marked +/- and a
cable with a
USB plug on the end made to plug into a USB socket on the computer. It also
has a USB cable.
The hard drive has:
USB 2.0 TM
I have no more info on it and can't find it with searching Google.
I am having no luck making it work or show up in lsusb.
Have any of you any ideas where I might look for info on how to hook
it up and
try to use it?

That +/- jack sounds like it's for an AC adaptor to plug into. I have
very little experience with USB, and none with USB drives, but I would
think a hard drive might be pushing the limit of power available over
the USB bus. Hence perhaps it needs an AC adaptor to power it up
before it will work, rather than getting power from the USB bus?

I think 3.5" drives take 12V to run the spinny-bits motor, at more
current than it can extract from the 5V@500mA that USB provides.

You're right, drives do generally need 12v in addition to 5v. But,
they will never get that needed 12v out of the USB bus, since the
USB bus doesn't provide anything but 5v.

I would be quite hesitant to start with 12v, for the simple reason
that if the drive is expecting less voltage, you risk doing damage.

We don't know what's inside the unit other than, obviously, the
hard drive and a USB to whatever (presumably IDE) converter. It
may run off 12v and then drop it internally for where it needs 5v,
or it may start with 5v and shift it up to 12v with an inverter, or
it may start with some completely different voltage.

As I said, I have no experience with USB drives. But I barely have
any devices that use AC adaptors that use the same voltage or even
connector. Even that parallel Zip drive I bought last year doesn't
use the same adaptor as the USB Zip drive I bought this year.