Picture Time (Feb 22 2007)


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Profile Matt Lebofsky
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Message 521975 - Posted: 23 Feb 2007, 4:22:08 UTC
Last modified: 23 Feb 2007, 4:26:09 UTC

No real news today - I mostly just dealt with fallout from the past couple of days' heavy activity. But I did take some (bad) photos and put up a new album regarding the recent network changes in the Photo Album section of our web site. Enjoy! (if that's the kind of thing you enjoy).

Edit: I should add that with all the recent news about the stolen laptop being recovered by SETI@home - this was made possible by BOINC. SETI@home Classic didn't have the capacity to track such activity. Another reason the switch to BOINC was a good thing.

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Message 522012 - Posted: 23 Feb 2007, 5:47:08 UTC - in response to Message 521975.

No real news today - I mostly just dealt with fallout from the past couple of days' heavy activity. But I did take some (bad) photos and put up a new album regarding the recent network changes in the Photo Album section of our web site. Enjoy! (if that's the kind of thing you enjoy).

Edit: I should add that with all the recent news about the stolen laptop being recovered by SETI@home - this was made possible by BOINC. SETI@home Classic didn't have the capacity to track such activity. Another reason the switch to BOINC was a good thing.

- Matt


Thanks for the Post Matt . . . 'luv the Big ReOrg' Pics - Quite the Archive

for SETI / BOINC / Berkeley . . . too bad i wasn't there to take Photo's all

the time ;)

note: on your edit - Thank God for the Science eh.

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Message 522510 - Posted: 24 Feb 2007, 5:22:25 UTC

Thanks for posting the pics...Seeing them kind of brings the project to life...so it's not just something that's just out there...I like seeing the people and the hardware that make this project work...I think maybe it might help the fund drive if you posted some more pictures of the older equipment that is still at work for SETI@home...Seeing how computer technology has advanced for the home user in the past few years...I think some people would be shocked to see some of the ancient equipment that the project still must rely on due to budget constraints.
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Message 522599 - Posted: 24 Feb 2007, 10:34:40 UTC

Thanks for the pics, Matt...
Lots of people were pretty vocal about the lack of info from the team at Berkeley, and you've done a sterling job of correcting this.
Makes us crunchers feel more like the important part of the project that we like to think we are!

PS anybody wanna donate a dual-rectified UPS to a poor student? I've lost a heap of crunching time to Summer and Autumn storms since November! lol... just kidding, of course!
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Message 522614 - Posted: 24 Feb 2007, 11:18:17 UTC - in response to Message 522599.

PS anybody wanna donate a dual-rectified UPS to a poor student?

WTF is dual rectified?
I've only ever heard of standby & on-line UPSs.

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Message 522645 - Posted: 24 Feb 2007, 13:01:29 UTC - in response to Message 522614.

PS anybody wanna donate a dual-rectified UPS to a poor student?

WTF is dual rectified?
I've only ever heard of standby & on-line UPSs.


Dual rectified is a variety of online UPS.
The AC input is stepped down and rectified to DC and charges a battery. A feed from the battery is inverted to become DC and then stepped up, to power the PC and peripherals. Essentially, it isolates the PC from the mains, and therefore protects fully from sudden large spikes of the kind we get here in Oz. It's also very useful in remote locations, where diesel generators provide power, due to the lack of a national grid source.
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Message 522703 - Posted: 24 Feb 2007, 16:18:14 UTC

Hey Matt, thanks eh, this news thread is for real.even got pictures, I like pictures. I took a break from swearing at the nest of wires here to look at your closet, funny how much simpler it made my nest look :)
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Message 522705 - Posted: 24 Feb 2007, 16:22:48 UTC - in response to Message 522645.
Last modified: 24 Feb 2007, 16:32:10 UTC

PS anybody wanna donate a dual-rectified UPS to a poor student?

WTF is dual rectified?
I've only ever heard of standby & on-line UPSs.


Dual rectified is a variety of online UPS.
The AC input is stepped down and rectified to DC and charges a battery. A feed from the battery is inverted to become DC and then stepped up, to power the PC and peripherals. Essentially, it isolates the PC from the mains, and therefore protects fully from sudden large spikes of the kind we get here in Oz. It's also very useful in remote locations, where diesel generators provide power, due to the lack of a national grid source.



Ummm, when you say "A feed from the battery is inverted to become DC and then stepped up," don't you actually mean "A feed from the battery is inverted to become AC and then stepped up,"?

What you've just described is the standard UPS (for the non-technical out there, Uninterruptable Power Source) -- where does the second rectification come in? I'd expect a second stage, and maybe a second battery in there, for a "Dual Rectified" UPS... (the computer would draw down the battery closer to the mains before the one closer to the load, I guess)

Or possibly there would be two standard UPS's in parallel, joined only at the power input, and the power output, both UPS's with the same rating as the entire box.

BTW, if your UPS fails, always test the battery(ies) - it(they) may be the only component(s) that has(have) failed.
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Message 522733 - Posted: 24 Feb 2007, 17:55:50 UTC - in response to Message 522705.

...What you've just described is the standard UPS (for the non-technical out there, Uninterruptable Power Source) -- where does the second rectification come in? I'd expect a second stage, and maybe a second battery in there, ...

Nothing clever. Just Marketing psuedo-tech technobabble-speak to confuse the unwary out of extra money for nothing extra...

Unfortunately, such "kool-speak" by Marketing can corrupt everyday usage to the point where the original technical meaning is corrupted beyond useful meaning :-(

Happy crunchin',
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Message 522799 - Posted: 24 Feb 2007, 20:51:08 UTC - in response to Message 522705.


What you've just described is the standard UPS (for the non-technical out there, Uninterruptable Power Source) -- where does the second rectification come in? I'd expect a second stage, and maybe a second battery in there, for a "Dual Rectified" UPS... (the computer would draw down the battery closer to the mains before the one closer to the load, I guess)

The most common type of UPS is called a "standby" UPS.

Power is taken from the mains and passed through to the load, and some runs the battery charger, but the inverter is not running.

When the power drops out the load switches and the inverter starts -- and the capacitors in the power supply bridge the few milliseconds while all of that happens.

The other type, where the inverter runs continuously, is fairly unusual these days, and generally more expensive.

Which reminds me, today looks like a good day for UPS testing -- I have six hours on battery.

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Message 522878 - Posted: 24 Feb 2007, 23:17:24 UTC - in response to Message 522799.
Last modified: 24 Feb 2007, 23:17:49 UTC

...Which reminds me, today looks like a good day for UPS testing -- I have six hours on battery.

But isn't that normal for a laptop?

Happy crunchin',
Martin

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Message 522929 - Posted: 25 Feb 2007, 0:00:07 UTC - in response to Message 522645.

PS anybody wanna donate a dual-rectified UPS to a poor student?

WTF is dual rectified?
I've only ever heard of standby & on-line UPSs.


Dual rectified is a variety of online UPS.
The AC input is stepped down and rectified to DC and charges a battery. A feed from the battery is inverted to become DC and then stepped up, to power the PC and peripherals. Essentially, it isolates the PC from the mains, and therefore protects fully from sudden large spikes of the kind we get here in Oz. It's also very useful in remote locations, where diesel generators provide power, due to the lack of a national grid source.

Ah, so it's just another name for an online UPS.

As others have mentioned-
Standby UPS, the load runs from the mains. When the mains drops out the inverter starts up & the load swithes to the battery powered output.
Online UPS, the load is always running from the batteries, there is no switchover from mains power to battery power when the mains drops out.
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Message 523023 - Posted: 25 Feb 2007, 5:03:34 UTC - in response to Message 522705.
Last modified: 25 Feb 2007, 5:33:33 UTC

PS anybody wanna donate a dual-rectified UPS to a poor student?

WTF is dual rectified?
I've only ever heard of standby & on-line UPSs.


Dual rectified is a variety of online UPS.
The AC input is stepped down and rectified to DC and charges a battery. A feed from the battery is inverted to become DC and then stepped up, to power the PC and peripherals. Essentially, it isolates the PC from the mains, and therefore protects fully from sudden large spikes of the kind we get here in Oz. It's also very useful in remote locations, where diesel generators provide power, due to the lack of a national grid source.



{quote]Ummm, when you say "A feed from the battery is inverted to become DC and then stepped up," don't you actually mean "A feed from the battery is inverted to become AC and then stepped up,"?


YES, that's what I meant to type, but what I typed was not what I meant to type.
Another slip of the typing finger, I'm afraid...

What you've just described is the standard UPS (for the non-technical out there, Uninterruptable Power Source) -- where does the second rectification come in? I'd expect a second stage, and maybe a second battery in there, for a "Dual Rectified" UPS... (the computer would draw down the battery closer to the mains before the one closer to the load, I guess)


There is, I believe, only one set of batteries. The second rectification is really a misnower, as it is an inversion... conversion of DC to AC I've found out some refer to this as "dual conversion" (which is more correct, I reckon). And yes, many people simply refer to it as an online UPS.

Or possibly there would be two standard UPS's in parallel, joined only at the power input, and the power output, both UPS's with the same rating as the entire box.

BTW, if your UPS fails, always test the battery(ies) - it(they) may be the only component(s) that has(have) failed.[/quote]

As far as I know, batteries are the major reason for UPS failure. Sadly, they are like the rest of us and have a limited lifetime!
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Message 523025 - Posted: 25 Feb 2007, 5:11:24 UTC - in response to Message 522799.


What you've just described is the standard UPS (for the non-technical out there, Uninterruptable Power Source) -- where does the second rectification come in? I'd expect a second stage, and maybe a second battery in there, for a "Dual Rectified" UPS... (the computer would draw down the battery closer to the mains before the one closer to the load, I guess)

The most common type of UPS is called a "standby" UPS.

Power is taken from the mains and passed through to the load, and some runs the battery charger, but the inverter is not running.

When the power drops out the load switches and the inverter starts -- and the capacitors in the power supply bridge the few milliseconds while all of that happens.


They're also known as "offline" UPS over here, Ned. They are fine as far as they go. That is, they keep you up and running in a blackout, but they are NOT a good idea if there's a storm, unless you disconnect them from the mains. The majority of suburban power lines here in Oz are ABOVE ground, which means you have to turn off your PC(s) if there's a storm.

The other type, where the inverter runs continuously, is fairly unusual these days, and generally more expensive.


I wouldn't like to use any other type, for the reason quoted above. It's just too risky, unless you disconnect from the mains, and allow the batteries to drain. Not so bad if you only have one or two PCs, but in a larger network, with servers, etc, or in an area powered by diesel gennies that tend to surge a bit, the more expensive option is the only one. Australia has a lot of such installations. Most of our mines are in remote locations, with no National Grid supply.

Which reminds me, today looks like a good day for UPS testing -- I have six hours on battery.


Lucky bludger! ;)
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Message 523028 - Posted: 25 Feb 2007, 5:26:14 UTC
Last modified: 25 Feb 2007, 5:29:55 UTC

OK...

I thought it might be an idea to post this: UPS types

The site explains pretty simply the differences between the THREE types of UPS.
Double rectified UPS are called dual conversion UPS on this site.

Martin's statement: "Marketing psuedo-tech technobabble-speak to confuse the unwary out of extra money for nothing extra..." is very accurate! Many compnies use different terminology to describe the same thing, making it look as though THEIR technology is superior, when there is, in fact, little difference!
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Message 523031 - Posted: 25 Feb 2007, 6:17:59 UTC - in response to Message 522878.

...Which reminds me, today looks like a good day for UPS testing -- I have six hours on battery.

But isn't that normal for a laptop?

Happy crunchin',
Martin

Actually, Martin, I've not had a laptop that is that good.

I have five servers, and some miscellaneous stuff (CSU/DSU, ethernet and the like) powered by a pair of APC 2200RMs through an automatic transfer switch (either UPS can run everything, and it switches when the batteries flame out).

One of the APCs has the factory batteries, the other has four Group 24 size AGM batteries (not exactly factory approved). I'm planning on doing the same with the other one someday.

We've had two outages, the longest was nearly 2 hours.
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Message 523033 - Posted: 25 Feb 2007, 6:26:48 UTC - in response to Message 523023.


Or possibly there would be two standard UPS's in parallel, joined only at the power input, and the power output, both UPS's with the same rating as the entire box.
To do this, the two inverters have to be in-phase, or else the result gets very exciting. That's what the automatic transfer switch does -- keep the two UPS outputs isolated


BTW, if your UPS fails, always test the battery(ies) - it(they) may be the only component(s) that has(have) failed.


As far as I know, batteries are the major reason for UPS failure. Sadly, they are like the rest of us and have a limited lifetime![/quote]
The biggest problem with the typical UPS that I've seen is that the batteries are too small, and as a result the charging rate is much too high.

Replace the "factory" batteries with something 25 or 50 times higher capacity and the batteries will likely live longer.

Of course, YMMV. Anyone else who does this does so at their own risk.
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Message 523043 - Posted: 25 Feb 2007, 7:41:04 UTC - in response to Message 523033.

[quote]
Or possibly there would be two standard UPS's in parallel, joined only at the power input, and the power output, both UPS's with the same rating as the entire box.
To do this, the two inverters have to be in-phase, or else the result gets very exciting. That's what the automatic transfer switch does -- keep the two UPS outputs isolated[quote]

*Chuckle*
Peak-to-trough (180 degrees out of phase would produce sparks you could see from a fair distance away! Anyone remember the formula for converting between peak voltage and RMS?

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Message 523050 - Posted: 25 Feb 2007, 8:05:17 UTC - in response to Message 523028.

The site explains pretty simply the differences between the THREE types of UPS.

Looking at that site i can still only see 2 types of UPS.
Standby & online.
Most standby UPSs provide power conditioning (they can keep a stable output for short periods of high or low supply voltage (within 20% or so of the nominal mains voltage) without switching to the battery output. Only the really cheap units provide no power conditiong at all.
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Message 523051 - Posted: 25 Feb 2007, 8:06:17 UTC - in response to Message 523043.

Anyone remember the formula for converting between peak voltage and RMS?

.707 comes to mind.

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