Power supply recommendations

[David Bandel]

On Mon, 22 Nov 2004 19:17:11 -0600, Alma J Wetzker <almaw at ieee.org> wrote:
> Alan Jackson wrote:
> > Well, I'm not much of a hardware guy, but I know some of you are.
> >
> > The fan on my power supply has failed, so I need to get another. It is
> > a SKY HAWK SH250ATX, 250 watt. Should I just replace it with an identical
> > one, or are there recommendations for something different? (The system was
> > first booted up in May, 2001). Or maybe all power supplies are created equal?
> > I doubt that!
> >
> 
> I like something bigger than that.  350's or 400's at least.  I tend to run at
> least one CD device and at least one hard drive.  Some of the new graphics
> cards take some power, fans like to spin and add in cards all take a bit.  I
> tend to upgrade parts piecemeal until I can afford a new mobo and I can jack
> up all the cards and slide it into place.  That leaves an old, working mobo
> and all the old cards that I can put together for kids or give-away (with
> linux, of course).
> 
> If you do not tend to upgrade, the same rating may be ok.  Not all PS's are
> created equal.  You can find them for under $20.00.  I tend to like the ones
> that run quieter, so that they have more expensive fans.  That usually implies
> better components all round.  YMMV
> 
>      -- Alma
> 
> If you have too many watts, everything runs just fine, even with a cheap part.
>   If you have too few watts, things get flaky and then die strangely.
> 

What I have found during the past few years, is that newer (especially
cheaper) power supplies have a lot of components that are no longer
installed on the board.  Unfortunately, those components are filters,
dampeners, and regulators that used to be necessary.  In general, if
you buy a _server_ power supply, you'll still find those components on
the board, but desktop supplies are lacking.  These components helped
extend the life of computer components.

Unfortunately, I see the same trend in UPSs.  The dampeners and
regulators (power supply geeks might call them zener diodes, etc., but
to most of us they're just filter components) have also been removed
from UPSs making them little more than batteries.  And while batteries
(which are really just big capacitors) dampen surges somewhat, as do
isolation transformers, etc., the new battery USPs aren't running off
the batteries all the time so the big dampeners are effectively not in
the circuit at the most critical times.

That's how you make cheap power supplies and UPSs.  By removing
"unnecessary" components.  Funny how those components were necessary
when the supply was originally designed, but now aren't.

Ciao,

David A. Bandel
-- 
Focus on the dream, not the competition.
            - Nemesis Air Racing Team motto