[Asterisk-Users] Qs about FXO/FXS cards

[Bob Goddard]

On Monday 03 January 2005 00:39, Andrew Kohlsmith wrote:
[...]
> Everyone keeps coming back to this "light power supply" and I just do not
> buy it.  Period.  I'm sorry, Steven, but it's bullshit.  I'm speaking as an
> electronics design engineer and as someone who's been playing with this
> kind of stuff for the better part of a decade.  "light power supply" is
> like "irritable bowel syndrome" -- it's what you call the problem when you
> haven't been able to isolate the cause and the patient is demanding to know
> what's wrong with him.
>
> Xeon 2.4GHz system, triple-redundant power supplies, Supermicro server
> motherboard, hot-swap everything.  +5 and +12V lines are within +/- 40mV of
> their target voltages, measured with a 100MHz DSO -- it is *not* a power
> issue.  P3-700 with 12 IDE drives in it, 350 or 450W (but decent make)
> power supply: Power quality is slightly lower but still what I would call
> acceptable.
[...]

What matters is the volts, amps and the voltage drop when the rails
are put under load. You have to ask yourself how many amps does the
mb require on each rail and can the psu supply it? The total power
supplied by the psu means nothing if it supplies all that power over
the 12v line but leave nothing for 5v.


B