Michael Kennedy wrote
Rod Speed wrote
Michael Kennedy wrote
Rod Speed wrote
John Doe wrote

Anybody know of a USB flash drive being damaged
during a typical electrical storm or whatever other
common electricity surge? (I'm not talking about a
lightning strike close enough to destroy the whole computer.)

I'm wondering about the possibility that a hard drive and
a USB flash drive could be destroyed at the same time,
given the flash drive is always attached to the USB port,

It can happen if the lightning strike kills the power
supply and massively over voltages the 5V rail.

It would be safer to put the flash drive on a powered USB hub.

Just wondering Rod, how'd you come to that conclusion?

For the reason I mentioned in the quoting you snipped and I have restored.

More than likely the usb hub will be plugged into the same
electrical source as the PC

Yes.

and therefore also be effected by the by the power surge.

Nope, not when its a simple wall wart plug pack for the powered hub.

Would it not?

Fraid not.

That makes sense when I think about it...

Yeah, its more subtle than it looks initially.

You're saying the SMPS will essentially blow up and allow unregulated current through

No, I am saying that that CAN happen. ATX power supplys are supposed
to be designed to not let that happen, but it does happen, particularly with
the cheapest power supplys that are pared bad component wise.

where as the transformer will continue to reduce voltage although not all the way to 5v it will
still probably be in the safe range for the flash drive.

No, its more complicated than that too. A transformer based wall wart
wont usually get damaged by that sort of lightning strike he asked about,
essentially because the spike has to get thru the transformer to damage
the voltage regulator. That isnt likely because of the massive impedance
of the transformer to the spike. And even if the voltage regulator does get
zapped, the most that you can get on the output is the unregulated voltage
which wouldnt normaly be more than about 10V at most with a 5V plug pack.
Whereas with the ATX SMPS that has been killed by the lightning strike,
the unregulated over voltage would likely be a lot higher than that and
with much more current available too.