Re: System Failure - CPU Task

Michael is talking about a $500 UPS. Most are only using
$100 standby UPSes. An on-line UPS that costs five times more
provides nothing useful to a computer.

Meanwhile what is the THD for that UPS? Is it a modified or
true sine wave? Words that mean nothing without the THD
number. Some modified sine wave UPSes output so much noise as
to even be destructive to some small electric motors and power
strip protectors. Still that high noise UPS is completely
irrelevant to a computer whose internal protection makes that
noise totally irrelevant. And so it is called computer grade.

No, a computer grade UPS is not cleanest because computer
power supplies are so resilient. But again, I will do what
Michael W Ryder does not. I will provide numbers. For
example, this computer grade UPS outputs two 200 volts square
waves with a spike of up to 270 volts between those square
waves. That is clean 120 volts? Yep. The manufacturer calls
those square waves and spike a 'modified sine wave'. And he
is correct. It is a modified sine wave. Basic 60 Hz 120 volt
sine wave is inside all that other noise. Electricity from a
computer grade UPS not clean enough for some appliances and
yet more than sufficient for a computer.

Those educated in retail store rumors may believe "A
computer grade UPS output is far cleaner than the output from
the main power lines." If true, then Michael can cite
numerical specifications. Michael makes his claims without
citing important numbers such as THD.

That trend underlies all my posts here. Those who post
urban myths will routinely avoid the numbers and technical
facts. Where are the numerical specifications from the UPS he
recommends? We have yet to see any numbers in his
recommendations. Exactly what propagandists do. Hype a
myth. Never provide relevant numbers nor underlying 'whys'.

Another myth is that "Nor do you have to worry about the
power going off, then on, then off, then ...". If one has to
worry about this, then one purchased defective equipment. If
cycling occurs too fast or too often, a computer's power
supply controller locks out the power supply. Again, no
problem. But then we have myths without first learning
functions inside a power supply system. Again, an example of
those who just know without first learning underlying
principles.

This knowledge shortage among 'computer assemblers' is why
so many recommend a UPS for anything other than data
protection from blackouts and brownouts. That is what a
plug-in UPS does - not to be confused with serious building
wide UPSes that accomplish more. The plug-in UPS does not
filter noise. It is for data protection from blackouts and
brownouts.

Many who fail to post manufacturer spec numbers will make
subjective claims anyway. This is why UPSes are widely
recommended for other problems such as noise - recommended
without first learning facts and underlying principles.

A perfect example is Michael's claim that "A computer grade
UPS output is far cleaner than the output from the main power
lines." If true, then power strip protectors would be OK in
UPS outputs. Manufacturers quietly caution to not connect
power strip protectors in a computer grade UPS. Computer
grade UPS in battery backup mode is some of the dirtiest
electricity. No problem because computer power supplies
already contain functions that make that and other noise
irrelevant.

Michael, a little suggestion. I have been doing this stuff
for a few generations - including a term working with and
designing power supplies. IOW I have a degree or two. The
typical computer grade UPS does not work as you have assumed.
Yes - assumed. Consult manufacturer spec numbers if you can
find that full page plus. Manufacturers don't like these
numbers widely distributed. No numbers makes it easier for
myth purveyors to hype unchallenged. But I am challenging -
and bluntly. If you are so sure otherwise, well, let's see a
URL with those manufacturer's numbers. You did first learn
the numbers? Good. Let's see them.

For those looking for noise protection, the topic was
discussed on 28 Oct 2005 in the newsgroup aus.hi-fi
entitled "UPS any use?" Provided were solutions for noise
filtering.

"Michael W. Ryder" wrote:
> Where in my post did I say I was talking about a "typical" UPS? The
> post you first responded to was about an On-line UPS, that is, one that
> only uses line power to recharge the batteries, and then uses the
> batteries to power the converters that provide the power to the
> equipment. The only noise output from one of these is in the conversion
> of the DC power to a sine wave type output, in other words, nothing
> compared to the noise you can get from regular mains power.
> ...
>
> What??? A computer grade UPS output is far cleaner than the output from
> the main power lines. You don't have the ups and downs of the power
> along with the various ripples induced by turning on and off large
> pieces of equipment or faulty lines. Nor do you have to worry about the
> power going off, then on, then off, then ... This will kill almost any
> equipment, including computer power supplies. Yes, a good, that is
> expensive, power supply may filter out most of the "junk" that comes
> into it, but that junk also stresses the components, lowering their life
> expectancy. It is much better to start with "clean" power from a good
> on-line UPS.
.