rec.autos.simulators

by **Larr** » Wed, 04 Sep 2002 01:10:27

Ask APC, not me :)

-Larry

> "True SineWave" is a sales label. However what was the THD
> number in the specs. Some 'so called' sine wave UPSes are
> only closer to a sine wave than their other products because
> it outputs less harmonics - yet still too high to be a sine
> wave. What were the THD numbers - or did they make that spec
> hard to find?

> > Um, All SmartUPS series output True SineWave outputs...

> > Unless they changed something since I sold these several years ago...

> > -Larry

> > > > Be a bit careful with some UPS's if it will be in a bedroom or
other
> > > > quiet place. I bought an APC Pro700 a few months ago to replace my
> > ancient
> > > > 400.

> > > OOPS. I just checked my records, and it was a Smart UPS 700NET, not
a
> > > Pro 700.

> > > --
> > > If there is a no_junk in my address, please REMOVE it before replying!
> > > All junk mail senders will be prosecuted to the fullest extent of the
> > > law!!
> > > http://www.racesimcentral.net/~andyross

by **w_to** » Wed, 04 Sep 2002 01:09:38

None of the devices are going to help even if "they have a
port for the DSL Line to filter it as well." What filter?
DSL is radio waves. If he gets a filter, then he does not get
DSL?

The power devices hype a surge protector - not a phone line
filter. But a surge protector without the short connection to
central earth ground does not provide effective protection.
Short because destructive surges are radio frequency. But
moreso, the telco traditionally installs effective surge
protection on the phone line - free - and less than 10 feet to
earth ground. Just another reason why those UPS or power
conditioner phone line protectors are nonsense.

A xDSL modem affected by AC line noise is defective by
design. However even the best xDSL modems cannot do anything
to clean up bad wiring. Just another reason why that xDSL
phone line should be, minimally, UTP (Unshielded Twisted Pair)
also known as Cat3, Cat5, or Cat6 wire. Wire that is even
sold in Home Depot and Lowes.

> I agree, if the problem is on the DSL line, none of the Power devices
> described will help UNLESS they have a port for the DSL Line to filter
> it as well. I think some of the newer one's do.

> -Larry

by **w_to** » Wed, 04 Sep 2002 07:49:29

I don't believe APC made a claim here that their UPS outputs
a sine wave. If one says a UPS outputs a sine wave, then a
basic number demonstrates same. A THD number is not difficult
to post. Unfortunately, when it comes to plug-in UPSes, the
web is full of claims from those who have never read
specifications - and from manufacturers that imply one thing
while their specifications say something quite different. All
we require is a basic specification number that says it
actually is a sine wave output. THD would do quite nicely.

The point is not to embarrass you, but to expand upon what
Andy Rossmann said:
>>> Be a bit careful with some UPS's ...
Too many urban myths are promoted when too many half truths
are told by the manufacturer. Is that really a since wave UPS
- or just a better sine wave than their cheaper model?

For example, the APC SmartUPS 700 claims a sine wave
output. But I recall reading elsewhere a THD of something
around 10% on the third harmonic. That's too dirty to be a
sine wave. Why not at least provide some numbers especially
since no UPS outputs a pure sine wave? But they don't.
Instead they encourage wild speculation by only telling half
truths and by hiding the numbers. Is it really a sine wave,
or just the closest to a sine wave in their product line?

> Ask APC, not me :)

> -Larry

> > "True SineWave" is a sales label. However what was the THD
> > number in the specs. Some 'so called' sine wave UPSes are
> > only closer to a sine wave than their other products because
> > it outputs less harmonics - yet still too high to be a sine
> > wave. What were the THD numbers - or did they make that spec
> > hard to find?

> > > Um, All SmartUPS series output True SineWave outputs...

> > > Unless they changed something since I sold these several years ago...

> > > -Larry

> > > > > Be a bit careful with some UPS's if it will be in a bedroom or
> other
> > > > > quiet place. I bought an APC Pro700 a few months ago to replace my
> > > ancient
> > > > > 400.

> > > > OOPS. I just checked my records, and it was a Smart UPS 700NET, not
> > > > a Pro 700.

by **Andrew Rossman** » Thu, 05 Sep 2002 06:58:27

All I can say is what APC says. For their SmartUPS, if you look at the
specs page, on the output/input/surge tab, it says the waveform is
'SineWave'. The standard BackUps says 'Stepped approximation to a
sinewave.'

I guess it depends on just how close to a sinewave you want. I've run a
fan on both a plain BackUPS and a SmartUPS. With the BackUPS, it
noticeably buzzes. With the SmartUPS, it ran normally.

I've read or heard that some UPS's don't even try for a sinewave. They
use some form of PWM that the switching supply in a computer will treat as
if it was a sinewave.

If you believe some of the claims of high-end-audio UPS's/filters, you
will get genuine, clean sinewaves, at a very steep cost.

Anybody have a 'scope and want to check what the output of various UPS's
looks like??

--
If there is a no_junk in my address, please REMOVE it before replying!
All junk mail senders will be prosecuted to the fullest extent of the
law!!
http://home.att.net/~andyross

by **Larr** » Thu, 05 Sep 2002 08:42:14

You're buying a UPS. Not a Stereo System.

-Larry

> I don't believe APC made a claim here that their UPS outputs
> a sine wave. If one says a UPS outputs a sine wave, then a
> basic number demonstrates same. A THD number is not difficult
> to post. Unfortunately, when it comes to plug-in UPSes, the
> web is full of claims from those who have never read
> specifications - and from manufacturers that imply one thing
> while their specifications say something quite different. All
> we require is a basic specification number that says it
> actually is a sine wave output. THD would do quite nicely.

> The point is not to embarrass you, but to expand upon what
> Andy Rossmann said:
> >>> Be a bit careful with some UPS's ...
> Too many urban myths are promoted when too many half truths
> are told by the manufacturer. Is that really a since wave UPS
> - or just a better sine wave than their cheaper model?

> For example, the APC SmartUPS 700 claims a sine wave
> output. But I recall reading elsewhere a THD of something
> around 10% on the third harmonic. That's too dirty to be a
> sine wave. Why not at least provide some numbers especially
> since no UPS outputs a pure sine wave? But they don't.
> Instead they encourage wild speculation by only telling half
> truths and by hiding the numbers. Is it really a sine wave,
> or just the closest to a sine wave in their product line?

> > Ask APC, not me :)

> > -Larry

- Show quoted text -

> > > "True SineWave" is a sales label. However what was the THD
> > > number in the specs. Some 'so called' sine wave UPSes are
> > > only closer to a sine wave than their other products because
> > > it outputs less harmonics - yet still too high to be a sine
> > > wave. What were the THD numbers - or did they make that spec
> > > hard to find?

> > > > Um, All SmartUPS series output True SineWave outputs...

> > > > Unless they changed something since I sold these several years
ago...

> > > > -Larry

message

> > > > > > Be a bit careful with some UPS's if it will be in a bedroom or
> > other
> > > > > > quiet place. I bought an APC Pro700 a few months ago to replace
my
> > > > ancient
> > > > > > 400.

> > > > > OOPS. I just checked my records, and it was a Smart UPS 700NET,
not
> > > > > a Pro 700.

by **Larr** » Thu, 05 Sep 2002 08:43:30

Correct.

That's what it was when I sold the line, and that's what it says now.

If the gent wants to shop by THD, then he's more than welcome to :)

-Larry

> All I can say is what APC says. For their SmartUPS, if you look at the
> specs page, on the output/input/surge tab, it says the waveform is
> 'SineWave'. The standard BackUps says 'Stepped approximation to a
> sinewave.'

> I guess it depends on just how close to a sinewave you want. I've run a
> fan on both a plain BackUPS and a SmartUPS. With the BackUPS, it
> noticeably buzzes. With the SmartUPS, it ran normally.

> I've read or heard that some UPS's don't even try for a sinewave. They
> use some form of PWM that the switching supply in a computer will treat as
> if it was a sinewave.

> If you believe some of the claims of high-end-audio UPS's/filters, you
> will get genuine, clean sinewaves, at a very steep cost.

> Anybody have a 'scope and want to check what the output of various UPS's
> looks like??

> --
> If there is a no_junk in my address, please REMOVE it before replying!
> All junk mail senders will be prosecuted to the fullest extent of the
> law!!
> http://home.att.net/~andyross

by **Eldre** » Sun, 08 Sep 2002 09:59:42

>IT Services.

>What can I say :)

I'm in IT too, but I don't have all that ***at home. Nevermind the fact that
I couldn't AFFORD it...<g>

Eldred
--
Homepage - http://www.racesimcentral.net/~epickett
GPLRank:+8.03
N2002 Rank:+20.124

Remove SPAM-OFF to reply.

by **Larr** » Mon, 09 Sep 2002 02:34:41

It helps when I work from home, which I do one day a week.

Plus, I'm a Geek who's been doing this for 22 years. What can I say :)

-Larry

> >IT Services.

> >What can I say :)

> I'm in IT too, but I don't have all that ***at home. Nevermind the fact
that
> I couldn't AFFORD it...<g>

> Eldred
> --
> Homepage - http://www.racesimcentral.net/~epickett
> GPLRank:+8.03
> N2002 Rank:+20.124

> Remove SPAM-OFF to reply.

by **Larr** » Mon, 09 Sep 2002 02:35:12

Also, I build all my own stuff, so the cost isn't as bad as it would seem.

-Larry

> >IT Services.

> >What can I say :)

> I'm in IT too, but I don't have all that ***at home. Nevermind the fact
that
> I couldn't AFFORD it...<g>

> Eldred
> --
> Homepage - http://www.racesimcentral.net/~epickett
> GPLRank:+8.03
> N2002 Rank:+20.124

> Remove SPAM-OFF to reply.

rec.autos.simulators

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OT: How many watts do i need in a UPS