Thanks, that all sounds reasonable.
It is not practical to make clear recommendations from these tests,
because of the number of dimensions in the phase space that have not
been explored:
- how other external drives of the same model draw power and respond
to the bus voltage, (manufacturing var
James, et al,
Monitoring the transient voltage minimums, running on battery, not
charging, with 2 ethernet dongles as additional load I get the following in
my testing of WD external "my passport" drive:
XO4 -- voltage droops to 4.51 -- spins up reliably
XO1.75 -- voltage droops to 4.56 -- spins
What did the bus voltage do during these events?
A HD would probably decide not to spin up if the bus voltage was out
of spec.
On Tue, Aug 13, 2013 at 02:00:31PM -0400, George Hunt wrote:
> Hi all,
>
> Following James' suggestion, I put my fluke 186 multimeter in current mode on
> the USB cable
Hi all,
Following James' suggestion, I put my fluke 186 multimeter in current mode
on the USB cable between the power source and the WD hard disk. I was able
to capture a 1A current spike, and a ~ 3 second current transient of about
800mA during spin up. The idling current for the hard disk, whi
