Re: (OT) Storage (8*IDE HDs) any experiences? +55v

[Hamish Moffatt <hamish@debian.org>]

Alvin.. have you really been following this thread at all?

On Tue, May 01, 2001 at 05:43:57PM -0700, Alvin Oga wrote:
> and if the power supply to the disk dies...
>     than you're out of luck
> 	or if the powersupply tot eh motherboard dies...
>  	you'd be out of luck too

So what? It's always been about load sharing, not redundancy.

> in which case...whats thepoint of having 2 PS ???
> 	- if it cannot handle the load...get a bigger power supply
> 
> 	- having 2 power supplies complicates things..
> 	and some devices running at 12.5v and others at 11.5v..
> 	at the extreme voltage ranges ... similarly for +5v range
> 	and +3.3 ranges...( all kinds of possible random timing problems?? 

I don't think this is likely to cause much problem really.
For one thing, the logic between the controller and the drive
is running on 5V (I'd guess), not 12V. 5V logic is generally
pretty tolerant...

> if you do have 2 power supplies.. you should invest in a 
> properly designed load-sharing power circuitry such that the other
> supply can drive all devices it needs by itself...

Huh? The disks and the motherboard will never be independent.

Summary: I think disks and motherboard on separate power supplies
will work. Connect the grounds together. (They'll be connected by
mains neutral/earth, as well as case ground, anyway, but just
to be thorough.)

Yes, there will be differences in the supply voltages, but I
don't see that being a significant problem with 5V logic.

No, I haven't tried it. But yes, I do know something about electronics.


Hamish
-- 
Hamish Moffatt VK3SB <hamish@debian.org> <hamish@cloud.net.au>