Battery backup: problem with my APC?
kenk
split-second power outage. Despite the fact that my battery shows all 5
lights lit, the computer died.
Is there a better brand to use than APC? Can the battery be sub-par
even though the test lights say it is OK? What have others of you chosen?
Thanks
Ken K
Ato_Zee
On 14-Oct-2009, kenk <ke...@nowhere.com> wrote:
> I was sitting at my desk yesterday during a storm when there was a
> split-second power outage. Despite the fact that my battery shows all 5
> lights lit, the computer died.
The computer died as in it won't run off the mains any more?
Or just the APC unit died?
Battery monitoring may be a chip that is independent, and
reports battery state when other parts have failed.
So could be one of the power semiconductors.
Mustek is an alternative, looks a better build quality,
but that is no guarantee of random failure..
Yousuf Khan
I've tried so many different UPSes that I've given up on them. None of
them last long, and none of them are guaranteed to save you from a power
outage. Worthless pieces of garbage, they are.
Yousuf Khan
Mike Ruskai
<bbb...@spammenot.yahoo.com> dribble thusly:
If you spend nothing on them, that's certainly true. Don't fault the
technology if you can't spec out the appropriate unit. I have everything
sensitive on a UPS, including my computers, external drives, and even my TiVo.
Power outages of less than several minutes don't affect me. I generally shut
things down after about three minutes, because in my area, that usually means
the power will be out for a couple of hours (typically because some idiot
driving in the rain took out a power pole).
You probably bought cheap, undersized units, which is why you've come to your
erroneous conclusion.
Mike Ruskai
dribble thusly:
Your "died" is pretty vague. It's possible there was a surge that exceeded
the suppression ability of the UPS. It's also possible that your computer's
power requirements exceed the capacity of the UPS. The value varies, but
typically the number of watts the unit can supply is 60% of the VA value.
Ian D
"kenk" <ke...@nowhere.com> wrote in message
news:hb5gj5$dir$1...@news.eternal-september.org...
I would be looking at your PC's power supply. There is a very
brief delay between the loss of power, and the UPS switchover
to battery power. The PC power supply should hold during
this period. Before I had a UPS, a split-second power outage
would cause clocks to lose their time, etc., sometimes, even
my monitor would blink, but the computer would hold without
a glitch. If you want to test your UPS, pull the power cord with
a load on the UPS.
Ato_Zee
> Also bear in mind that
> batteries typically last only a few years at best, you have to change them
> or buy a new UPS at regular intervals. (And of course every manufacturer
> will have the occasional "lemon.")
3 to 5 years seems typical for the commonly used sealed lead
acid batteries in this application, where they are maintined on
a float charge. OP has not said what APC model is referred to,
and the indication referred to may only be for battery voltage,
which is a different issue to whether the battery still has
sufficient capacity to supply the initial surge when the inverter
starts, and then maintain the load.
The only real test is to have the load connected, put a
voltmeter across the battery (warning the battery is at the
utility supply voltage and live WRT to the case etc.)
then pull the plug and see what happens to its
voltage. In my experience, with a 3 or so year old battery,
you see around 13V across the battery, pull the plug
and instead of the inverter starting to feed the load,
the battery drops to a few volts.
Most APC units have the make and catalog number
of the batteries (commonly there are two) on each
battery.
There are internal fuses on the PCB and in the hope
that it is only the batteries replace the batteries,
they usually have push on blade connections.
One or more domestic tungsten bulbs can be
used as a test load, and do remember that when the
inverter starts, even with no utility supply connected,
dangerous voltages are generated.
.
Rod Speed
> kenk <ke...@nowhere.com> wrote
>> I was sitting at my desk yesterday during a storm when there was a split-second power outage. Despite the fact that
>> my battery shows all 5 lights lit, the computer died.
>> Is there a better brand to use than APC? Can the battery be sub-par
>> even though the test lights say it is OK? What have others of you chosen?
> I would be looking at your PC's power supply. There is a very
> brief delay between the loss of power, and the UPS switchover
> to battery power.
Not with continuous UPSs, there is no delay at all with those.
Essentially the PC is running off the UPS output all the time and
the only thing that changes with the mains failure is that the UPS
isnt being charged anymore and runs off the battery instead.
Igor Batinic
kenk wrote:
> I was sitting at my desk yesterday during a storm when there was a
> split-second power outage. Despite the fact that my battery shows all 5
> lights lit, the computer died.
There might be several problems which can be the reason of that behaviour.
> Is there a better brand to use than APC? Can the battery be sub-par
> even though the test lights say it is OK? What have others of you chosen?
APC is OK brand. I would not call it the best, and also, you probably
have line-interactive UPS. The problem is that such a UPS can not
eliminate all of the problems, and also, some power supplies are not
working well with that king of UPS (I've heard about problems with
certain Chieftek PSs).
Best regards,
Iggy
Igor Batinic
Yousuf Khan wrote:
> kenk wrote:
>>
>> Is there a better brand to use than APC? Can the battery be sub-par
>> even though the test lights say it is OK? What have others of you
>> chosen?
>
> I've tried so many different UPSes that I've given up on them. None of
> them last long, and none of them are guaranteed to save you from a power
> outage. Worthless pieces of garbage, they are.
Next time you want to press the "send" button, please, re-read and
re-think again.
With best regards,
Iggy
Ian D
"Rod Speed" <rod.sp...@gmail.com> wrote in message
news:7jp3olF...@mid.individual.net...
> Ian D wrote
>> kenk <ke...@nowhere.com> wrote
>
>>> I was sitting at my desk yesterday during a storm when there was a
>>> split-second power outage. Despite the fact that my battery shows all 5
>>> lights lit, the computer died.
>
>>> Is there a better brand to use than APC? Can the battery be sub-par
>>> even though the test lights say it is OK? What have others of you
>>> chosen?
>
>> I would be looking at your PC's power supply. There is a very
>> brief delay between the loss of power, and the UPS switchover
>> to battery power.
>
> Not with continuous UPSs, there is no delay at all with those.
>
> Essentially the PC is running off the UPS output all the time and
> the only thing that changes with the mains failure is that the UPS
> isnt being charged anymore and runs off the battery instead.
>
wave output, and are relatively expensive. I was assuming
that the OP was using a regular, run of the mill APC UPS.
bbbl67
<BUTthann...@DONTearthlinkLIKE.netSPAM> wrote:
> You probably bought cheap, undersized units, which is why you've come to your
> erroneous conclusion.
Is not being able to hold a charge after only one year considered
junky enough? I bought a power supply appropriate for a home
environment, if I could afford to build a computer room with an AC/UPS
with alarm monitoring system in it, I would've done so, but not within
my budget, nor most people's budgets.
Yousuf Khan
Rod Speed
> Rod Speed <rod.sp...@gmail.com> wrote
>>>> I was sitting at my desk yesterday during a storm when there was a
>>>> split-second power outage. Despite the fact that my battery shows
>>>> all 5 lights lit, the computer died.
>>>> Is there a better brand to use than APC? Can the battery be
>>>> sub-par even though the test lights say it is OK? What have
>>>> others of you chosen?
>>> I would be looking at your PC's power supply. There is a very
>>> brief delay between the loss of power, and the UPS switchover
>>> to battery power.
>> Not with continuous UPSs, there is no delay at all with those.
>> Essentially the PC is running off the UPS output all the time and
>> the only thing that changes with the mains failure is that the UPS
>> isnt being charged anymore and runs off the battery instead.
> That's correct, and those units are the ones with true sine wave output,
Nope, the type of output is an entirely separate issue.
> and are relatively expensive.
Not anymore with continuous or online UPSs.
> I was assuming that the OP was using a regular, run of the mill APC UPS.
There's plenty of continuous/online consumer grade UPSs now.
David Brown
> Ian D wrote
>> Rod Speed <rod.sp...@gmail.com> wrote
>>> Ian D wrote
>>>> kenk <ke...@nowhere.com> wrote
>
>>>>> I was sitting at my desk yesterday during a storm when there was a
>>>>> split-second power outage. Despite the fact that my battery shows
>>>>> all 5 lights lit, the computer died.
>
>>>>> Is there a better brand to use than APC? Can the battery be
>>>>> sub-par even though the test lights say it is OK? What have
>>>>> others of you chosen?
>
>>>> I would be looking at your PC's power supply. There is a very
>>>> brief delay between the loss of power, and the UPS switchover
>>>> to battery power.
>
>>> Not with continuous UPSs, there is no delay at all with those.
>
>>> Essentially the PC is running off the UPS output all the time and
>>> the only thing that changes with the mains failure is that the UPS
>>> isnt being charged anymore and runs off the battery instead.
>
>> That's correct, and those units are the ones with true sine wave output,
>
> Nope, the type of output is an entirely separate issue.
>
Both types of UPS generate roughly sine wave outputs when the inverter
is active. The difference is that with a standby UPS, the inverter is
not active unless the power fails, so the output is just a filtered
version of the input.
>> and are relatively expensive.
>
> Not anymore with continuous or online UPSs.
>
Online or continuous UPSs are more expensive than standby UPS for the
same ratings. Judging by a quick check on APC's website, the difference
is something like 25% more expensive for "Smart UPS online" compared to
"Smart UPS" (standby).
Additionally, smaller and cheaper UPSs are mostly standby types, while
online ones are for more professional markets. If you are wanting
something that can give you 10 minutes at 300W, standby UPSs will be
half the price.
Online UPSs are also less efficient for smaller systems - the double
conversion wastes at least 10% of your electricity.
That doesn't mean that standby UPSs are a better choice for a small user
- just that there are different balances to consider and the price
difference (though less than it used to be) is significant.
Ato_Zee
On 15-Oct-2009, bbbl67 <yjk...@gmail.com> wrote:
> Is not being able to hold a charge after only one year considered
> junky enough? I bought a power supply appropriate for a home
> environment,
Most are sealed lead acid batteries, much like a vehicle
battery, and vehicle batteries generally have around a
3 year life.
Vehicles and UPS continuously float charge, and an
UPS is generally on, which is rather longer than in
vehicle useage, other than public transport which uses
heavy duty batteries most vehicles aren't driven
continuously throughout the day.
The operating conditions of UPS batteries can
rapidly deplete residual capacity.
Main benefit of UPS is during a brown out,
when flashing BIOS, and while MS$ is updating
and the PC says installing 27 updates, don't
switch off.
Rod Speed
> Rod Speed wrote
>> Ian D wrote
>>> Rod Speed <rod.sp...@gmail.com> wrote
>>>> Ian D wrote
>>>>> kenk <ke...@nowhere.com> wrote
>>>>>> I was sitting at my desk yesterday during a storm when there was a split-second power outage. Despite the fact
>>>>>> that my battery shows all 5 lights lit, the computer died.
>>>>>> Is there a better brand to use than APC? Can the battery be
>>>>>> sub-par even though the test lights say it is OK? What have
>>>>>> others of you chosen?
>>>>> I would be looking at your PC's power supply. There is a very
>>>>> brief delay between the loss of power, and the UPS switchover
>>>>> to battery power.
>>>> Not with continuous UPSs, there is no delay at all with those.
>>>> Essentially the PC is running off the UPS output all the time and
>>>> the only thing that changes with the mains failure is that the UPS
>>>> isnt being charged anymore and runs off the battery instead.
>>> That's correct, and those units are the ones with true sine wave output,
>> Nope, the type of output is an entirely separate issue.
> Both types of UPS generate roughly sine wave outputs when the inverter is active.
Pity he was clearly talking about TRUE sine wave output, which only
a small subset of UPSs produce. And it aint even the continuous/online
UPSs that mostly do produce TRUE sine wave output.
> The difference is that with a standby UPS, the inverter is not active unless the power fails, so the output is just a
> filtered version of the input.
Thats an entirely separate matter to TRUE sine wave output.
>>> and are relatively expensive.
>> Not anymore with continuous or online UPSs.
> Online or continuous UPSs are more expensive than standby UPS for the same ratings.
In theory that is correct. In practice there isnt a
lot in it with the brand name domestic UPSs now.
> Judging by a quick check on APC's website, the difference is something like 25% more expensive for "Smart UPS
> online" compared to "Smart UPS" (standby).
Thats not very much.
> Additionally, smaller and cheaper UPSs are mostly standby types, while online ones are for more professional markets.
Thats overstating it, particularly with the stuff out of china.
> If you are wanting something that can give you 10 minutes at 300W, standby UPSs will be half the price.
Wrong.
> Online UPSs are also less efficient for smaller systems - the double conversion wastes at least 10% of your
> electricity.
Utterly mangled all over again.
And if you do care about that, you can also get replacement power supplys
that avoid the double conversion and still have the UPS functionality.
> That doesn't mean that standby UPSs are a better choice for a small user - just that there are different balances to
> consider and the price difference (though less than it used to be) is significant.
Not anymore.
Rod Speed
> On 15-Oct-2009, bbbl67 <yjk...@gmail.com> wrote:
>
>> Is not being able to hold a charge after only one year considered
>> junky enough? I bought a power supply appropriate for a home
>> environment,
>
> Most are sealed lead acid batteries, much like a vehicle
> battery, and vehicle batteries generally have around a
> 3 year life.
Thats because of the deep cycling car batterys get, particularly in winter.
You get a lot longer than that with telephone exchanges etc.
> Vehicles and UPS continuously float charge, and an
> UPS is generally on, which is rather longer than in
> vehicle useage, other than public transport which uses
> heavy duty batteries most vehicles aren't driven
> continuously throughout the day.
But a UPS battery gets cycled a lot less than car batterys do.
> The operating conditions of UPS batteries
> can rapidly deplete residual capacity.
Yes, particularly with a poor charger that produces sulphation.
> Main benefit of UPS is during a brown out, when
> flashing BIOS, and while MS$ is updating and
> the PC says installing 27 updates, don't switch off.
And they do allow a graceful shutdown on mains failure too.
Mike Ruskai
<yjk...@gmail.com> dribble thusly:
If it couldn't hold a charge after only one year, you spent next to nothing
and got even less.
Three years is a typical battery replacement interval (if you can't replace
the battery, that's another sign you bought junk). You can get suitable UPS
units at a typical office store with replaceable batteries, sizable to your
computer's needs, for less than $200 (less than $100 if your required capacity
is low enough).
If you insist that your claim about UPS's being junk is not ridiculous, then
provide some model numbers or brands/capacities that you've tried. Even the
very inexpensive 1100VA Belkin unit I started with several years back worked
better than you describe.
David Lesher
>I was sitting at my desk yesterday during a storm when there was a
>split-second power outage. Despite the fact that my battery shows all 5
>lights lit, the computer died.
What happens when you pull the wall plug on the UPS?
Does the machine die or not?
--
A host is a host from coast to coast.................wb8foz@nrk.com
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433
Yousuf Khan
> If you insist that your claim about UPS's being junk is not ridiculous, then
> provide some model numbers or brands/capacities that you've tried. Even the
> very inexpensive 1100VA Belkin unit I started with several years back worked
> better than you describe.
You sound like you work for a UPS company, otherwise why are you so
invested in it? Just accept that people have different experiences than
you, and move on.
Yousuf Khan
Yousuf Khan
> Next time you want to press the "send" button, please, re-read and
> re-think again.
I stand by my assertion, I've had different experiences than you. You
need to get some experience and follow your own advice.
> With best regards,
Right.
Yousuf Khan
Yousuf Khan
> Ian D wrote
>> brief delay between the loss of power, and the UPS switchover
>> to battery power.
>
> Not with continuous UPSs, there is no delay at all with those.
>
> Essentially the PC is running off the UPS output all the time and
> the only thing that changes with the mains failure is that the UPS
> isnt being charged anymore and runs off the battery instead.
If the battery is not holding a charge anymore, then it will die right
away whether it is an online or standby PS.
Yousuf Khan
Rod Speed
> Mike Ruskai wrote
>> If you insist that your claim about UPS's being junk is not
>> ridiculous, then provide some model numbers or brands/capacities
>> that you've tried. Even the very inexpensive 1100VA Belkin unit I
>> started with several years back worked better than you describe.
> You sound like you work for a UPS company,
Nope.
> otherwise why are you so invested in it?
Presumably he believes that the claim that all UPSs are junk is mindlessly silly.
> Just accept that people have different experiences than you, and move on.
Separate matter entirely to the stupid claim that all UPSs are junk.
Rod Speed
Yes, but that is an entirely separate matter
to what he said about the PC power supply.
Igor Batinic
Yousuf Khan wrote:
> Igor Batinic wrote:
>> Next time you want to press the "send" button, please, re-read and
>> re-think again.
>
> I stand by my assertion, I've had different experiences than you. You
> need to get some experience and follow your own advice.
It seems that I have a lot more experience than you have. From my point
of view (ant not only mine, as it seems) you've never seen a real UPS in
life. Maybe not even a picture of it.
With best regards,
Iggy
Mike Ruskai
<bbb...@spammenot.yahoo.com> dribble thusly:
>Mike Ruskai wrote:
No, what I sound like is a person who's incredulous that someone could say
something so blatantly ignorant about uninterruptible power supplies. I guess
you've never had a file system crash, or lost an important document that
hadn't been saved.
Your reluctance to provide any detail demonstrates that you probably have
little to no actual experience with UPS's of reasonable quality. It's like
someone who's driven nothing but 20-year-old used junkers saying that all cars
are unreliable junk.
Ed Light
The batteries last more than 3 years but it's necessary to check them
regularly. I boot to something that will be ok if the PC stops -- a CD
would be ok. Then I pull the wall plug and see what happens. Afterwards
the software in Windows gives an estimate of run time.
Only the system unit, cable modem, and monitor are on the battery.
A bug in the software keeps entending the run time estimate, though.
Also the software doesn't let you set the shut down windows point close
to dead battery. Also, the data line protectors can impede the data. Had
to get my cable modem out of there as the cable company measured that it
was fouling it up.
As a UPS it's great, though.
--
Ed Light
Better World News TV Channel:
http://realnews.com
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Iraq Veterans Against the War:
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Send spam to the FTC at
sp...@uce.gov
Thanks, robots.
David Brown
I don't know exactly what you mean by "TRUE sine wave" - all UPS's
generate a sine wave of sorts when they are active (i.e., all the time
for continuous/online UPS's, or during power fail for standby devices).
The quality of the sine wave varies from fairly poor (lots of
harmonics) to pretty good (few harmonics), but is /never/ pure.
If you are restricting discussion only to those UPS's that produce good
quality sine waves, then I'll have to take your word for how standby and
online UPS prices compare. Baring the worst of the cheapo devices, the
sine quality of any UPS is going to be good enough for computer
hardware, and is typically better than you get straight from the mains.
Thus it's not a restriction that I've considered.
>> The difference is that with a standby UPS, the inverter is not
>> active unless the power fails, so the output is just a filtered
>> version of the input.
>
> Thats an entirely separate matter to TRUE sine wave output.
>
True - though again, there is no such thing as "TRUE sine wave output",
merely more or less harmonics.
>>>> and are relatively expensive.
>
>>> Not anymore with continuous or online UPSs.
>
>> Online or continuous UPSs are more expensive than standby UPS for
>> the same ratings.
>
> In theory that is correct. In practice there isnt a lot in it with
> the brand name domestic UPSs now.
>
OK. It looks to me that the difference has been getting smaller in
recent years - perhaps we are merely arguing about what sort of
percentage is a "big" difference. I also have been looking mainly at
APC, rather than a spread of suppliers - I've used them, I have found
them reliable, and they work well with Linux, so I haven't bothered
looking at many alternative manufacturers.
>> Judging by a quick check on APC's website, the difference is
>> something like 25% more expensive for "Smart UPS online" compared
>> to "Smart UPS" (standby).
>
> Thats not very much.
>
In a recent purchase, the online device I bought was actually twice the
cost of a standby device with similar ratings. But that was because I
needed it to work with a particularly hostile mains supply, thus it was
a special case.
To be honest, however, the prices I saw when I checked APC's website
surprised me slightly - I had expected a bigger difference. But one
should never let hard facts get in the way of a good argument.
>> Additionally, smaller and cheaper UPSs are mostly standby types,
>> while online ones are for more professional markets.
>
> Thats overstating it, particularly with the stuff out of china.
>
>> If you are wanting something that can give you 10 minutes at 300W,
>> standby UPSs will be half the price.
>
> Wrong.
>
Well, that's based on looking at APC's website. There is no doubt that
the cheapest APC standby device, which is perfectly good for a single
system, is less than half the price of their cheapest online device.
For their small devices, there is a huge difference in prices.
But as I say I haven't looked at other manufacturers - in particular, I
haven't looked at the low-end and unbranded devices. I simply took APC
as a familiar professional-level UPS supplier, and I expect other
professional-level suppliers to be roughly in line with them.
If what you are saying is true of the low-end devices, then that's
interesting news. I'm not sure I'd normally pick a no-name UPS - when
looking for reliability during a power failure, the supplier's
reputation is a factor. But there are certainly situations when a cheap
UPS is much better than no UPS.
>> Online UPSs are also less efficient for smaller systems - the
>> double conversion wastes at least 10% of your electricity.
>
> Utterly mangled all over again.
>
No, it's quite simple - AC to DC conversion has some loses, DC to AC
conversion has some loses. Simple passive filtering and surge
protection, as used by standby devices when they are offline, has
virtually no loss.
I'm not too concerned about this myself, but other people certainly are,
especially in larger setups.
> And if you do care about that, you can also get replacement power
> supplys that avoid the double conversion and still have the UPS
> functionality.
>
If you are talking about DC supply buses to servers, rather than having
an AC supply to each, then I think it's a very good idea. It is quite
simply idiotic to take a high voltage AC supply, convert it to low
voltage DC for a battery, turn it back to high voltage AC to deliver to
a server's power supply, which then turns it back to a low voltage DC.
Converting AC to 24V to 48V DC for battery storage, and passing that
straight to a server's power supply would be significantly more
efficient in energy use, and much smaller and cheaper in hardware.
Rod Speed
Should be obvious to even someone as stupid as you.
> - all UPS's generate a sine wave of sorts when they are active
Wrong, as always. Plenty generate a square wave instead.
> (i.e., all the time for continuous/online UPS's, or during power fail for standby devices). The quality of the sine
> wave varies from fairly poor (lots of harmonics) to pretty good (few harmonics), but is /never/ pure.
That last is just plain wrong.
> If you are restricting discussion only to those UPS's that produce good quality sine waves,
I was JUST commenting on HIS claim about TRUE sine wave output, fuckwit.
> then I'll have to take your word for how standby and online UPS prices compare. Baring the worst of the cheapo
> devices, the sine quality of any UPS is going to be good enough for computer hardware, and is typically better than
> you get straight from the mains. Thus it's not a restriction that I've considered.
Completely and utterly irrelevant to the comment I made about
his stupid pig ignorant claim about TRUE sine wave output.
>>> The difference is that with a standby UPS, the inverter is not
>>> active unless the power fails, so the output is just a filtered
>>> version of the input.
>> Thats an entirely separate matter to TRUE sine wave output.
> True - though again, there is no such thing as "TRUE sine wave output", merely more or less harmonics.
Wrong, as always. True sinewave is NO harmonics.
>>>>> and are relatively expensive.
>>>> Not anymore with continuous or online UPSs.
>>> Online or continuous UPSs are more expensive than standby UPS for the same ratings.
>> In theory that is correct. In practice there isnt a lot in it with the brand name domestic UPSs now.
> OK. It looks to me that the difference has been getting smaller in recent years - perhaps we are merely arguing about
> what sort of percentage is a "big" difference.
Nope.
> I also have been looking mainly at APC, rather than a spread of suppliers - I've used them, I have found them
> reliable, and they work well with Linux, so I haven't bothered looking at many alternative manufacturers.
You should when commenting on the price difference between
online/continuous and standby consumer grade UPSs.
>>> Judging by a quick check on APC's website, the difference is something like 25% more expensive for "Smart UPS
>>> online" compared to "Smart UPS" (standby).
>> Thats not very much.
> In a recent purchase, the online device I bought was actually twice the cost of a standby device with similar ratings.
The technical term for that is 'pathetically inadequate sample'
> But that was because I needed it to work with a particularly hostile mains supply, thus it was a special case.
> To be honest, however, the prices I saw when I checked APC's website surprised me slightly - I had expected a bigger
> difference. But one should never let hard facts get in the way of a good argument.
You'll end up completely blind if you dont watch out.
The difference is even less with non brand name consumer products.
>>> Additionally, smaller and cheaper UPSs are mostly standby types, while online ones are for more professional
>>> markets.
>> Thats overstating it, particularly with the stuff out of china.
>>> If you are wanting something that can give you 10 minutes at 300W, standby UPSs will be half the price.
>> Wrong.
> Well, that's based on looking at APC's website.
The technical term for that is 'pathetically inadequate sample'
> There is no doubt that the cheapest APC standby device, which is perfectly good for a single system, is less than half
> the price of their cheapest online
> device. For their small devices, there is a huge difference in prices.
The technical term for that is 'pathetically inadequate sample'
> But as I say I haven't looked at other manufacturers - in particular,
> I haven't looked at the low-end and unbranded devices.
And you will find egg all over your face if you do.
> I simply took APC as a familiar professional-level UPS supplier, and I expect other professional-level suppliers to be
> roughly in line with them.
More fool you.
> If what you are saying is true of the low-end devices, then that's
> interesting news. I'm not sure I'd normally pick a no-name UPS
You have always been, and always will be, completely and utterly irrelevant.
> - when looking for reliability during a power failure, the supplier's reputation is a factor.
Only for fools.
> But there are certainly situations when a
> cheap UPS is much better than no UPS.
Funny that.
>>> Online UPSs are also less efficient for smaller systems - the
>>> double conversion wastes at least 10% of your electricity.
>> Utterly mangled all over again.
> No,
Yep.
> it's quite simple - AC to DC conversion has some loses, DC to AC conversion has some loses.
Pity you utterly mangled that number that is straight from your arse.
> Simple passive filtering and surge protection, as used by standby devices when they are offline, has virtually no
> loss.
That wasnt what you utterly mangled.
> I'm not too concerned about this myself, but other people certainly are, especially in larger setups.
If you are concerned about that, the way to eliminate that
is to use a UPS that replaces the current power supply so
there is no second loss of going from AC to DC again.
>> And if you do care about that, you can also get replacement power supplys that avoid the double conversion and still
>> have the UPS functionality.
> If you are talking about DC supply buses to servers,
Nope, its just as true of desktop PCs.
> rather than having an AC supply to each, then I think it's a very good idea. It is quite simply idiotic to take a
> high voltage AC supply, convert it to low voltage DC for a battery, turn it back to high voltage AC to deliver to a
> server's power supply, which then turns it back to a low voltage DC.
It isnt idiotic, its just not as efficient. Many dont give a damn
about the efficiency with a device that isnt taking that much power.
> Converting AC to 24V to 48V DC for battery storage, and passing that straight to a server's power supply
Just as true of a desktop's power supply.
> would be significantly more efficient in energy use,
Not very significantly, actually.
> and much smaller and cheaper in hardware.
Nope, its actually more expensive, essentially because that approach
doesnt sell in the same volume that traditional UPSs do.
David Brown
You might know about /buying/ and /using/ UPS's, but you don't know much
about sine waves, AC/DC conversion, harmonics, and related
technicalities. A square wave (as produced by very low-end UPS's) is
just a sine wave with large harmonics. And at the high end, good UPS's
use PWM switching to produce something closer to a sine wave - even
after filtering, it is still not a "TRUE" sine wave.
>> (i.e., all the time for continuous/online UPS's, or during power
>> fail for standby devices). The quality of the sine wave varies from
>> fairly poor (lots of harmonics) to pretty good (few harmonics),
>> but is /never/ pure.
>
> That last is just plain wrong.
>
I'll accept that the first part might be wrong - a square wave is a very
poor sine wave, rather than just "fairly poor". As I have said, I
haven't been looking at such low end devices.
However, if you think that UPS's generate *true* sine waves with no
harmonics, I'd love to see the circuit diagrams. I'd also like to know
which brands go to great efforts to get closest to a sine wave - so that
I can avoid them, as it would be a total waste of money.
>> If you are restricting discussion only to those UPS's that produce
>> good quality sine waves,
>
> I was JUST commenting on HIS claim about TRUE sine wave output,
> fuckwit.
So I can't talk about UPS's that don't produce mythical "TRUE sine
waves" because a previous poster talked about "TRUE sine wave" UPS's,
but /you/ can talk about any UPS's you like? I'm sure that makes sense
to you, somehow.
>
>> then I'll have to take your word for how standby and online UPS
>> prices compare. Baring the worst of the cheapo devices, the sine
>> quality of any UPS is going to be good enough for computer
>> hardware, and is typically better than you get straight from the
>> mains. Thus it's not a restriction that I've considered.
>
> Completely and utterly irrelevant to the comment I made about his
> stupid pig ignorant claim about TRUE sine wave output.
>
>>>> The difference is that with a standby UPS, the inverter is not
>>>> active unless the power fails, so the output is just a
>>>> filtered version of the input.
>
>>> Thats an entirely separate matter to TRUE sine wave output.
>
>> True - though again, there is no such thing as "TRUE sine wave
>> output", merely more or less harmonics.
>
> Wrong, as always. True sinewave is NO harmonics.
>
Correct - a "true sine wave" has no harmonics. No UPS could possibly
produce one. There is no point in an UPS even trying - it makes sense
to limit the first few harmonics as much as practically possible, but
you get very little gain from going further than that.
Surely you are aware that a "true" sinewave exists only as a
mathematical concept - anything in real life is only going to be an
approximation?
<snip the incoherent rodbot responses>
>> If you are talking about DC supply buses to servers,
>
> Nope, its just as true of desktop PCs.
>
I've only seen discussions of DC supply buses in the context of server
racks, where you have lots of machines together. Since desktop PC's are
typically spread out, you can't conveniently have a single AC to DC
supply for multiple machines.
>> rather than having an AC supply to each, then I think it's a very
>> good idea. It is quite simply idiotic to take a high voltage AC
>> supply, convert it to low voltage DC for a battery, turn it back to
>> high voltage AC to deliver to a server's power supply, which then
>> turns it back to a low voltage DC.
>
> It isnt idiotic, its just not as efficient. Many dont give a damn
> about the efficiency with a device that isnt taking that much power.
>
True enough for machines with low power requirements. But the
discussion here has moved on to multiple machines - for server racks,
the electricity price is often a very big part of the cost.
>> Converting AC to 24V to 48V DC for battery storage, and passing
>> that straight to a server's power supply
>
> Just as true of a desktop's power supply.
>
It is indeed true of a desktop's power supply - but unless a significant
percentage of users start using UPSs with their desktops, the economics
won't allow anything but AC supplies on desktops.
>> would be significantly more efficient in energy use,
>
> Not very significantly, actually.
>
For people with big installations, even small percentages are
significant. But a rough rule of thumb would be 3-5% energy loss for
each high voltage AC to low voltage DC conversion, assuming top of the
range converters. By avoiding the extra conversion to AC after the UPS
and before the server supplies, you'd save up to 10%.
>> and much smaller and cheaper in hardware.
>
> Nope, its actually more expensive, essentially because that approach
> doesnt sell in the same volume that traditional UPSs do.
>
Economics of scale are certainly relevant. But server rack UPS and
supply systems are not huge volumes anyway, and the energy savings would
be appealing. And the hardware itself would be smaller and a lot
cheaper once volumes are of similar magnitudes.
Ed Light
> Rod Speed wrote:
David, alot of us have Rod filtered out.
David Brown
> David Brown wrote:
>> Rod Speed wrote:
>
> David, alot of us have Rod filtered out.
>
I know, and I don't often enter discussions with him. However, he has
some useful things to say if you can avoid triggering the rodbot switch,
as I did for part of my post. Anyway, it's possible that other people
find something of interest in what I wrote, even if Rod disagrees with it.
Rod Speed
Guess which pathetic little prat has just got egg all over its silly little face, yet again ?
I was DESIGNING that stuff before you were even born thanks child.
> A square wave (as produced by very low-end UPS's) is just a sine wave with large harmonics.
Thanks for that completely superfluous proof that you have
never ever had a fucking clue about anything at all, ever.
They are generated completely differently, fool.
> And at the high end, good UPS's use PWM switching to produce something closer to a sine wave - even after filtering,
> it is still not a "TRUE" sine wave.
Never ever said it was, fuckwit.
>>> (i.e., all the time for continuous/online UPS's, or during power
>>> fail for standby devices). The quality of the sine wave varies from
>>> fairly poor (lots of harmonics) to pretty good (few harmonics),
>>> but is /never/ pure.
>> That last is just plain wrong.
> I'll accept that the first part might be wrong - a square wave is a very poor sine wave, rather than just "fairly
> poor".
Its nothing like a sine wave, fool.
> As I have said, I haven't been looking at such low end devices.
You have always been, and always will be, completely and utterly irrelevant.
What you might or might not have been looking at in spades.
> However, if you think that UPS's generate *true* sine waves with no harmonics,
Never ever said anything even remotely resembling anything like that.
It is perfectly possible to generate pure sine waves.
No one bothers with a UPS because there isnt any point in doing that.
> I'd love to see the circuit diagrams. I'd also like to know which brands go to great efforts to get closest to a sine
> wave -
> so that I can avoid them, as it would be a total waste of money.
Didnt say that anyone does, JUST that your stupid pig ignorant
claim that its NEVER possible is just plain pig ignorant and wrong.
>>> If you are restricting discussion only to those UPS's that produce good quality sine waves,
>> I was JUST commenting on HIS claim about TRUE sine wave output, fuckwit.
> So I can't talk about UPS's that don't produce mythical "TRUE sine
> waves" because a previous poster talked about "TRUE sine wave" UPS's, but /you/ can talk about any UPS's you like?
I was JUST commenting on HIS claim about TRUE SINE WAVE OUTPUT, fuckwit.
> I'm sure that makes sense to you, somehow.
Never ever could bullshit its way out of a wet paper bag.
>>> then I'll have to take your word for how standby and online UPS
>>> prices compare. Baring the worst of the cheapo devices, the sine quality of any UPS is going to be good enough for
>>> computer
>>> hardware, and is typically better than you get straight from the
>>> mains. Thus it's not a restriction that I've considered.
>> Completely and utterly irrelevant to the comment I made about his stupid pig ignorant claim about TRUE sine wave
>> output.
>>>>> The difference is that with a standby UPS, the inverter is not
>>>>> active unless the power fails, so the output is just a
>>>>> filtered version of the input.
>>>> Thats an entirely separate matter to TRUE sine wave output.
>>> True - though again, there is no such thing as "TRUE sine wave
>>> output", merely more or less harmonics.
>> Wrong, as always. True sinewave is NO harmonics.
> Correct - a "true sine wave" has no harmonics. No UPS could possibly produce one.
Wrong. Its done for high power oscillators, fuckwit.
> There is no point in an UPS even trying
Separate matter entirely.
> - it makes sense to limit the first few harmonics as much as practically possible, but you get very little gain from
> going further than that.
Completely and utterly irrelevant to the comment I made about
his stupid pig ignorant claim about TRUE sine wave output.
> Surely you are aware that a "true" sinewave exists only as a
> mathematical concept - anything in real life is only going to be an
> approximation?
Never ever could bullshit its way out of a wet paper bag.
> <snip the incoherent rodbot responses>
More of you flagrant dishonesty when you get done like a fucking dinner, as always.
>>> If you are talking about DC supply buses to servers,
>> Nope, its just as true of desktop PCs.
> I've only seen discussions of DC supply buses in the context of server racks, where you have lots of machines
> together.
Your problem, as always.
> Since desktop PC's are typically spread out, you can't conveniently have a single AC to DC supply for multiple
> machines.
No one said anything about supplying multiple machines.
>>> rather than having an AC supply to each, then I think it's a very good idea. It is quite simply idiotic to take a
>>> high voltage AC supply, convert it to low voltage DC for a battery, turn it back to high voltage AC to deliver to a
>>> server's power supply, which then turns it back to a low voltage DC.
>> It isnt idiotic, its just not as efficient. Many dont give a damn
>> about the efficiency with a device that isnt taking that much power.
> True enough for machines with low power requirements. But the discussion here has moved on to multiple machines
No it hasnt.
> - for server racks, the electricity price is often a very big part of the cost.
Like hell it is.
>>> Converting AC to 24V to 48V DC for battery storage, and passing that straight to a server's power supply
>> Just as true of a desktop's power supply.
> It is indeed true of a desktop's power supply - but unless a
> significant percentage of users start using UPSs with their desktops,
> the economics won't allow anything but AC supplies on desktops.
A significant number do use UPSs on desktops.
>>> would be significantly more efficient in energy use,
>> Not very significantly, actually.
> For people with big installations, even small percentages are significant.
Wrong, as always.
> But a rough rule of thumb would be 3-5% energy loss for each high voltage AC to low voltage DC conversion, assuming
> top of the range converters. By avoiding the extra conversion to AC after the UPS and before the server supplies,
> you'd save up to 10%.
Utterly mangled all over again. And thats not very significant anyway.
>>> and much smaller and cheaper in hardware.
>> Nope, its actually more expensive, essentially because that approach doesnt sell in the same volume that traditional
>> UPSs do.
> Economics of scale are certainly relevant. But server rack UPS and supply systems are not huge volumes anyway,
No one but you is discussing those.
> and the energy savings would be appealing.
Nope. Fart in the bath.
> And the hardware itself would be smaller and a
> lot cheaper once volumes are of similar magnitudes.
They never ever will be.
David Brown
> David Brown wrote
>> Rod Speed wrote
>>> David Brown wrote
>>>> Rod Speed wrote
I know I shouldn't bother responding here, but it's hard to resist...
I'll try not to do it again.
>>>> I don't know exactly what you mean by "TRUE sine wave"
>
>>> Should be obvious to even someone as stupid as you.
>
>>>> - all UPS's generate a sine wave of sorts when they are active
>
>>> Wrong, as always. Plenty generate a square wave instead.
>
>> You might know about /buying/ and /using/ UPS's, but you don't know
>> much about sine waves, AC/DC conversion, harmonics, and related
>> technicalities.
>
> Guess which pathetic little prat has just got egg all over its silly
> little face, yet again ?
>
Let me guess - you?
> I was DESIGNING that stuff before you were even born thanks child.
>
Really? You were designing UPS's and inverters before I was born?
Perhaps you were making UPS's for IBM System/360 mainframes - there were
not that many computers around before I was born. So forgive me if I
find that claim just a /touch/ unbelievable.
As I say, you might know something about buying and using UPS's, but you
clearly do not have any idea of the electronics used in an inverter, or
of the mathematics underlying them.
>> A square wave (as produced by very low-end UPS's) is just a sine
>> wave with large harmonics.
>
> Thanks for that completely superfluous proof that you have never ever
> had a fucking clue about anything at all, ever.
>
> They are generated completely differently, fool.
>
/I/ know how they are generated, and how similar and different the
generation is - /you/ do not. The electronics is in principle the same
- it's just you need faster (therefore somewhat more expensive)
switching devices when you want to make something with less harmonics.
It also requires more effort in the controller and software (and
therefore more expense). In addition, different UPSs will have more or
less passive filtering after the inverter - again, the principle is the
same, but some will spend more on the components than others.
And as I said, a square wave is just a sine wave with large harmonics (I
didn't mention how they are generated). Ever heard of Fourier? For
someone who has been designing UPS's for nearly forty years, your
mathematical knowledge is somewhat lacking.
>> And at the high end, good UPS's use PWM switching to produce
>> something closer to a sine wave - even after filtering, it is still
>> not a "TRUE" sine wave.
>
> Never ever said it was, fuckwit.
>
So you now agree that there is no such thing as a "TRUE sine wave"
output from an UPS? It's a pity that you then contradict yourself
/again/ later on.
>>>> (i.e., all the time for continuous/online UPS's, or during
>>>> power fail for standby devices). The quality of the sine wave
>>>> varies from fairly poor (lots of harmonics) to pretty good (few
>>>> harmonics), but is /never/ pure.
>
>>> That last is just plain wrong.
>
>> I'll accept that the first part might be wrong - a square wave is a
>> very poor sine wave, rather than just "fairly poor".
>
> Its nothing like a sine wave, fool.
>
Here's a couple of links for the mathematically impaired:
<http://mathworld.wolfram.com/FourierSeriesSquareWave.html>
<http://cnx.org/content/m0041/latest/>
A square wave is a sine wave with a lot of harmonics. The relevance and
effect of these harmonics will depend on what you do with the output,
but you can't argue with the basic mathematical facts. Well, /you/
apparently /can/ argue with them, but you look a bit silly by doing so.
And for a final clue, let's try to think of an example of a real
application where a square wave is used to replace a sine wave. I know,
how about connecting a square wave output from an UPS to the power
supply of a computer, designed to work with a sine wave mains voltage.
My goodness - it works! It's almost as though the square wave does the
job of an approximate sine wave!
>> As I have said, I haven't been looking at such low end devices.
>
> You have always been, and always will be, completely and utterly
> irrelevant.
>
> What you might or might not have been looking at in spades.
>
>> However, if you think that UPS's generate *true* sine waves with no
>> harmonics,
>
> Never ever said anything even remotely resembling anything like that.
>
So you now agree that "TRUE sine wave" UPS's, as you have been calling
them, don't generate true sine waves? In fact, you now agree that /all/
UPS's generate approximate sine waves with harmonics?
>
> It is perfectly possible to generate pure sine waves.
>
Pray, tell me how to do so. If you can produce a /pure/ sine wave, I've
got a perpetual motion machine I'll sell you. Remember, we are talking
about *pure* sine waves, not just something /close/ to a sine wave.
> No one bothers with a UPS because there isnt any point in doing that.
>
At least you've learned that much from my posts.
>
>> I'd love to see the circuit diagrams. I'd also like to know which
>> brands go to great efforts to get closest to a sine wave - so that
>> I can avoid them, as it would be a total waste of money.
>
> Didnt say that anyone does, JUST that your stupid pig ignorant claim
> that its NEVER possible is just plain pig ignorant and wrong.
>
So you agree that these "TRUE sine wave" UPS's you've been talking about
are mythical? You even agree that close-to-sine UPS's don't exist
because no one wants to pay for them (though it would be possible to
make them).
>>>> True - though again, there is no such thing as "TRUE sine wave
>>>> output", merely more or less harmonics.
>
>>> Wrong, as always. True sinewave is NO harmonics.
>
>> Correct - a "true sine wave" has no harmonics. No UPS could
>> possibly produce one.
>
> Wrong. Its done for high power oscillators, fuckwit.
>
No, you do not use a "true sine wave UPS" for a high power oscillator -
you don't necessarily use an UPS at all.
Assuming that by your mangled attempt at a sentence, you meant to say
that a "high power oscillator" is a "true sine wave" generated by an
inverter like an UPS output, then you are still wrong. A "high power
oscillator" will generate it's signal in different ways, depending on
the application. And in particular, it will /never/ generate a /pure/
sine wave. It might have very low harmonics, depending on the needs of
the application, but it will never be pure.
You don't understand the mathematics involved, and you don't understand
the electronics. That's okay - you don't need to know how these devices
work to be able to use them. And just because I /do/ know how to design
UPS's and power supplies of different types and ratings, doesn't mean I
know more about buying or using them than other people. But you
certainly look pretty foolish with all your claims about impossible
devices because you don't understand the principles.
>> There is no point in an UPS even trying
>
> Separate matter entirely.
>
Again, you've learned.
>
>> Surely you are aware that a "true" sinewave exists only as a
>> mathematical concept - anything in real life is only going to be an
>> approximation?
>
> Never ever could bullshit its way out of a wet paper bag.
>
Well, you've learned /some/ things. Perhaps it's time to re-take the
remedial mathematics classes.
>>>> If you are talking about DC supply buses to servers,
>
>>> Nope, its just as true of desktop PCs.
>
>> I've only seen discussions of DC supply buses in the context of
>> server racks, where you have lots of machines together.
>
> Your problem, as always.
>
>> Since desktop PC's are typically spread out, you can't conveniently
>> have a single AC to DC supply for multiple machines.
>
> No one said anything about supplying multiple machines.
>
Yes, some talked about supplying multiple machines - /I/ did. Has no
one explained to you the concept of having a discussion involving more
than one person?
>>>> rather than having an AC supply to each, then I think it's a
>>>> very good idea. It is quite simply idiotic to take a high
>>>> voltage AC supply, convert it to low voltage DC for a battery,
>>>> turn it back to high voltage AC to deliver to a server's power
>>>> supply, which then turns it back to a low voltage DC.
>
>>> It isnt idiotic, its just not as efficient. Many dont give a damn
>>> about the efficiency with a device that isnt taking that much
>>> power.
>
>> True enough for machines with low power requirements. But the
>> discussion here has moved on to multiple machines
>
> No it hasnt.
>
>> - for server racks, the electricity price is often a very big part
>> of the cost.
>
> Like hell it is.
>
I forgot - you were /designing/ this stuff before I was born. Go back
to sleep in your rocking chair, old man, and dream of the sixties when
you knew something worth knowing. The rest of us here in 2009 know that
electricity costs are entirely relevant. Here's a link for the
google-impaired:
<http://arstechnica.com/business/news/2009/10/datacenter-energy-costs-outpacing-hardware-prices.ars>
>>>> Converting AC to 24V to 48V DC for battery storage, and passing
>>>> that straight to a server's power supply
>
>>> Just as true of a desktop's power supply.
>
>> It is indeed true of a desktop's power supply - but unless a
>> significant percentage of users start using UPSs with their
>> desktops, the economics won't allow anything but AC supplies on
>> desktops.
>
> A significant number do use UPSs on desktops.
>
Significant as a percentage of desktop users? I'd be surprised if it is
more than a couple of percent. Feel free to provide a link proving me
wrong.
>>>> would be significantly more efficient in energy use,
>
>>> Not very significantly, actually.
>
>> For people with big installations, even small percentages are
>> significant.
>
> Wrong, as always.
>
Again, I'd recommend those mathematics remedial classes. A small
percentage of a very big number is still a big number, and therefore
significant. Try out some examples with a calculator.
>> But a rough rule of thumb would be 3-5% energy loss for each high
>> voltage AC to low voltage DC conversion, assuming top of the range
>> converters. By avoiding the extra conversion to AC after the UPS
>> and before the server supplies, you'd save up to 10%.
>
> Utterly mangled all over again. And thats not very significant
> anyway.
>
You are remembering I was talking about big installations?
Are you sure you're not a banker? With claims like that, that 10%
savings on your main running costs being "not significant", you sound a
lot like the half-wits that brought us the current world economic situation.
Rod Speed
> Rod Speed wrote
>> David Brown wrote
>>> Rod Speed wrote
>>>> David Brown wrote
>>>>> Rod Speed wrote
> I know I shouldn't bother responding here,
Yeah, all you're doing is digging that hole you are in deeper and deeper.
You'll be out in china any day now.
> but it's hard to resist...
Only for fools like you.
> I'll try not to do it again.
Try harder, fuckwit child.
>>>>> I don't know exactly what you mean by "TRUE sine wave"
>>>> Should be obvious to even someone as stupid as you.
>>>>> - all UPS's generate a sine wave of sorts when they are active
>>>> Wrong, as always. Plenty generate a square wave instead.
>>> You might know about /buying/ and /using/ UPS's, but you don't know much about sine waves, AC/DC conversion,
>>> harmonics, and related technicalities.
>> Guess which pathetic little prat has just got egg all over its silly little face, yet again ?
> Let me guess - you?
Guess again, in front of a mirror next time.
>> I was DESIGNING that stuff before you were even born thanks child.
> Really?
Yep, really.
> You were designing UPS's and inverters before I was born?
I said THAT STUFF, fuckwit.
> Perhaps you were making UPS's for IBM System/360 mainframes - there were not that many computers around before I was
> born.
Didnt say it was for a computer, fuckwit.
> So forgive me if I find that claim just a /touch/ unbelievable.
You have always been, and always will be, completely and utterly irrelevant.
What you might or might not 'find' in spades.
> As I say, you might know something about buying and using UPS's, but you clearly do not have any idea of the
> electronics used in an inverter, or of the mathematics underlying them.
Guess which pathetic little prat has just got egg all over its silly little face, yet again ?
I was DESIGNING that stuff before you were even born thanks child.
>>> A square wave (as produced by very low-end UPS's) is just a sine wave with large harmonics.
>> Thanks for that completely superfluous proof that you have never ever had a fucking clue about anything at all, ever.
>> They are generated completely differently, fool.
> /I/ know how they are generated,
Then you are a terminal fuckwit if you seriously believe that UPSs
that produce a square wave output are producing a sine wave.
> and how similar and different the generation is - /you/ do not.
We'll see...
> The electronics is in principle the same
Thanks for that completely superfluous proof that you have
never ever had a fucking clue about anything at all, ever.
> - it's just you need faster (therefore somewhat more expensive)
> switching devices when you want to make something with less harmonics.
Thanks for that completely superfluous proof that you have
never ever had a fucking clue about anything at all, ever.
There isnt even ANY 'switching device' with high power sine wave generators, fuckwit child.
> It also requires more effort in the controller and software (and therefore more expense).
Thanks for that completely superfluous proof that you have
never ever had a fucking clue about anything at all, ever.
Dont need any software at all, fuckwit child.
> In addition, different UPSs will have more or less passive filtering after the inverter - again, the principle is the
> same, but some will spend more on the components than others.
Thanks for that completely superfluous proof that you have
never ever had a fucking clue about anything at all, ever.
> And as I said, a square wave is just a sine wave with large harmonics
Thanks for that completely superfluous proof that you have
never ever had a fucking clue about anything at all, ever.
> (I didn't mention how they are generated).
And thats where you fucked up VERY spectacularly indeed.
> Ever heard of Fourier?
Before you were even born thanks child.
> For someone who has been designing UPS's for nearly forty years, your mathematical knowledge is somewhat lacking.
Having fun thrashing that straw man, fuckwit child ?
>>> And at the high end, good UPS's use PWM switching to produce something closer to a sine wave - even after filtering,
>>> it is still not a "TRUE" sine wave.
>> Never ever said it was, fuckwit.
> So you now agree that there is no such thing as a "TRUE sine wave" output from an UPS?
Never ever said that either, fuckwit child.
> It's a pity that you then contradict yourself /again/ later on.
Everyone can see you are lying, again.
>>>>> (i.e., all the time for continuous/online UPS's, or during
>>>>> power fail for standby devices). The quality of the sine wave varies from fairly poor (lots of harmonics) to
>>>>> pretty good (few harmonics), but is /never/ pure.
>>>> That last is just plain wrong.
>>> I'll accept that the first part might be wrong - a square wave is a very poor sine wave, rather than just "fairly
>>> poor".
>> Its nothing like a sine wave, fool.
> Here's a couple of links for the mathematically impaired:
> http://mathworld.wolfram.com/FourierSeriesSquareWave.html
Doesnt say that a square wave is a sine wave, fuckwit child.
> http://cnx.org/content/m0041/latest/
Doesnt say that a square wave is a sine wave, fuckwit child.
> A square wave is a sine wave with a lot of harmonics.
Thats as stupid as claiming that ANY wave is a sine wave with a lot of harmonics, fuckwit child.
> The relevance and effect of these harmonics will depend on what you do with the output,
And if you generate a sine wave in the first place, there is fuck all in the way of harmonics, fuckwit child.
> but you can't argue with the basic mathematical facts.
You wouldnt know what a real mathematical fact was if it bit you on your lard arse, fuckwit child.
> Well, /you/ apparently /can/ argue with them, but you look a bit silly by doing so.
Have you the remotest concept of how many are pissing themselves laughing
at you desperately digging your hole deeper and deeper, fuckwit child ?
> And for a final clue, let's try to think of an example of a real
> application where a square wave is used to replace a sine wave.
Irrelevant to what you get when you generate a sine wave in the first place, fuckwit child.
> I know, how about connecting a square wave output from an UPS to the power supply of a computer, designed to work with
> a sine wave mains voltage. My goodness - it works! It's almost as though the square wave does the job of an
> approximate sine wave!
Completely and utterly irrelevant to whether its perfectly possible
to start with a sine wave in the first place, fuckwit child.
>>> As I have said, I haven't been looking at such low end devices.
>> You have always been, and always will be, completely and utterly irrelevant.
>> What you might or might not have been looking at in spades.
>>> However, if you think that UPS's generate *true* sine waves with no harmonics,
>> Never ever said anything even remotely resembling anything like that.
> So you now agree that "TRUE sine wave" UPS's, as you have been calling them,
Everyone can see for themselves that I never ever said anything like that, fuckwit child.
> don't generate true sine waves? In fact, you now agree that
> /all/ UPS's generate approximate sine waves with harmonics?
Having fun thrashing that straw man, fuckwit child ?
>> It is perfectly possible to generate pure sine waves.
> Pray, tell me how to do so.
You start with a sine wave and AMPLIFY it fuckwit child.
Done all the time with radio transmitters etc etc etc, fuckwit child.
Not just radio transmitters either, fuckwit child.
> If you can produce a /pure/ sine wave, I've got a perpetual motion machine I'll sell you.
Doesnt defy the laws of physics, fuckwit child.
> Remember, we are talking about *pure* sine waves,
Like hell we are. No one but YOU used that particular word, you pathetic excuse for a lying bullshit artist.
> not just something /close/ to a sine wave.
>> No one bothers with a UPS because there isnt any point in doing that.
> At least you've learned that much from my posts.
Lying, as always. Even someone as stupid as you should be able
to use groups.google and see that I have been saying that LONG
BEFORE YOU EVER SHOWED UP IN USENET, fuckwit child.
>>> I'd love to see the circuit diagrams. I'd also like to know which
>>> brands go to great efforts to get closest to a sine wave - so that I can avoid them, as it would be a total waste of
>>> money.
>> Didnt say that anyone does, JUST that your stupid pig ignorant claim that its NEVER possible is just plain pig
>> ignorant and wrong.
> So you agree that these "TRUE sine wave" UPS's you've been talking about are mythical?
Nope, its perfectly possible to produce one if you want one.
> You even agree that close-to-sine UPS's don't exist because no one wants to pay for them (though it would be possible
> to make them).
Nope, because they were produced back before it became
much easier to produce square waves instead, fuckwit child.
Look up rotary converters sometime, fuckwit child.
Those use the same technology that power
stations use to generate the mains, fuckwit child.
Corse now you will stupidly try to claim that the mains isnt a sine wave either.
>>>>> True - though again, there is no such thing as "TRUE sine wave output", merely more or less harmonics.
>>>> Wrong, as always. True sinewave is NO harmonics.
>>> Correct - a "true sine wave" has no harmonics. No UPS could possibly produce one.
>> Wrong. Its done for high power oscillators, fuckwit.
> No,
Yep.
> you do not use a "true sine wave UPS" for a high power oscillator
Never ever said you did, fuckwit child.
> - you don't necessarily use an UPS at all.
Perfectly possible to generate a high power sine wave, fuckwit child.
> Assuming that by your mangled attempt at a sentence,
Never ever could bullshit and lie its way out of a wet paper bag.
> you meant to say that a "high power oscillator" is a "true sine wave" generated by an inverter like an UPS output,
Stupid assumption.
> then you are still wrong.
Having fun thrashing that straw man, fuckwit child ?
> A "high power oscillator" will generate it's signal in different ways, depending on
> the application. And in particular, it will /never/ generate a /pure/ sine wave.
Thanks for that completely superfluous proof that you have
never ever had a fucking clue about anything at all, ever.
Its purer than the mains its replaces, fuckwit child.
> It might have very low harmonics, depending on the needs of the application, but it will never be pure.
Its purer than the mains its replaces, fuckwit child.
AND you've flagrantly dishonestly slithered off from TRUE to PURE, you lying bullshit artist.
> You don't understand the mathematics involved, and you don't understand the electronics.
Everyone can see for themselves that you are lying, fuckwit child.
> That's okay - you don't need to know how these devices work to be able to use them.
I was DESIGNING that stuff before you were even born thanks fuckwit child.
> And just because I /do/ know how to design UPS's and power supplies of different types and ratings,
In fact you clearly know fuck all about that.
Dont even know what a rotary converter is, fuckwit child.
> doesn't mean I know more about buying or using them than other people. But you certainly look pretty foolish with all
> your claims about impossible devices because you don't understand the principles.
Try telling that to those who have rotary converters, fuckwit child.
Dont be TOO surprised then they just laugh in your pathetic little pig ignorant face, AGAIN.
>>> There is no point in an UPS even trying
>> Separate matter entirely.
> Again, you've learned.
Again, you're lying.
>>> Surely you are aware that a "true" sinewave exists only as a mathematical concept - anything in real life is only
>>> going to be an approximation?
>> Never ever could bullshit its way out of a wet paper bag.
> Well, you've learned /some/ things. Perhaps it's time to re-take the remedial mathematics classes.
Nope, time for you to get a HUGE towel for the egg all over your silly little face, fuckwit child.
>>>>> If you are talking about DC supply buses to servers,
>>>> Nope, its just as true of desktop PCs.
>>> I've only seen discussions of DC supply buses in the context of server racks, where you have lots of machines
>>> together.
>> Your problem, as always.
>>> Since desktop PC's are typically spread out, you can't conveniently
>>> have a single AC to DC supply for multiple machines.
>> No one said anything about supplying multiple machines.
> Yes, some talked about supplying multiple machines - /I/ did.
Not till then you didnt, fuckwit child. And even all those
voices in your head dont qualify as SOME, fuckwit child.
> Has no one explained to you the concept of having a discussion involving more than one person?
Never ever could bullshit its way out of a wet paper bag.
>>>>> rather than having an AC supply to each, then I think it's a
>>>>> very good idea. It is quite simply idiotic to take a high
>>>>> voltage AC supply, convert it to low voltage DC for a battery,
>>>>> turn it back to high voltage AC to deliver to a server's power
>>>>> supply, which then turns it back to a low voltage DC.
>>>> It isnt idiotic, its just not as efficient. Many dont give a damn about the efficiency with a device that isnt
>>>> taking that much power.
>>> True enough for machines with low power requirements. But the discussion here has moved on to multiple machines
>> No it hasnt.
>>> - for server racks, the electricity price is often a very big part of the cost.
>> Like hell it is.
> I forgot - you were /designing/ this stuff before I was born.
Yep.
> Go back to sleep in your rocking chair, old man, and dream of the sixties when you knew something worth knowing. The
> rest of us here in 2009 know that electricity costs are entirely relevant.
Not when the cost of saving a small amount is higher than what you save, fuckwit child.
>>>>> Converting AC to 24V to 48V DC for battery storage, and passing that straight to a server's power supply
>>>> Just as true of a desktop's power supply.
>>> It is indeed true of a desktop's power supply - but unless a significant percentage of users start using UPSs with
>>> their desktops, the economics won't allow anything but AC supplies on desktops.
>> A significant number do use UPSs on desktops.
> Significant as a percentage of desktop users?
Yep.
> I'd be surprised if it is more than a couple of percent.
Your problem.
> Feel free to provide a link proving me wrong.
Feel free to go and fuck yourself, again.
>>>>> would be significantly more efficient in energy use,
>>>> Not very significantly, actually.
>>> For people with big installations, even small percentages are significant.
>> Wrong, as always.
> Again, I'd recommend those mathematics remedial classes.
Again, I'd recommend you go and fuck yourself, again, and
retake Bullshitting 101, you clearly slept thru the first time.
> A small percentage of a very big number is still a big number, and therefore significant.
What matters is how much it costs to save that, fuckwit child.
>>> But a rough rule of thumb would be 3-5% energy loss for each high
>>> voltage AC to low voltage DC conversion, assuming top of the range
>>> converters. By avoiding the extra conversion to AC after the UPS
>>> and before the server supplies, you'd save up to 10%.
>> Utterly mangled all over again. And thats not very significant anyway.
> You are remembering I was talking about big installations?
> Are you sure you're not a banker?
No point in asking you if you are a pathetic excuse for a lying bullshit artist.
The answer is obvious.
> With claims like that, that 10% savings on your main running costs being "not significant",
Never ever said that either, you silly little pathological liar.
> you sound a lot like the half-wits that brought us the current world economic situation.
It didnt happen that way, fuckwit child.
David Lesher
>So you now agree that there is no such thing as a "TRUE sine wave"
>output from an UPS? It's a pity that you then contradict yourself
>/again/ later on.
Well, I know of one design that I'd call same; but not sure you will.
The best ferro-resonant UPS's are damn close. Of course, such are neither
common or inexpensive.
[But then the line itself is never purely sinusoidal, either; it come
with flaws such as spikes and dropouts...]
The real question is: does the load care if it's not? If all loads are
switchers, usually not at all. Linear wall-warts may. Incandescent lamps
won't have a clue.
David Brown
> David Brown <da...@westcontrol.removethisbit.com> writes:
>
>
>> So you now agree that there is no such thing as a "TRUE sine wave"
>> output from an UPS? It's a pity that you then contradict yourself
>> /again/ later on.
>
>
> Well, I know of one design that I'd call same; but not sure you will.
> The best ferro-resonant UPS's are damn close. Of course, such are neither
> common or inexpensive.
>
I've no argument that you can generate very close to sine waves - for
most practical purposes, devices like these are effectively sinusoidal
with no harmonics that you normally need to consider. Every application
has its requirements for how good a sine wave it needs, and you can get
as close as you like (until you are limited by fundamental things like
thermal noise).
I've just been arguing about rodbot's descriptions of UPS outputs as
"true sine wave", and his claims that things like rotary converters and
the mains supply produce /pure/ sine waves with absolutely no harmonics.
> [But then the line itself is never purely sinusoidal, either; it come
> with flaws such as spikes and dropouts...]
>
> The real question is: does the load care if it's not? If all loads are
> switchers, usually not at all. Linear wall-warts may. Incandescent lamps
> won't have a clue.
Incandescent lamps /will/ care - they will prefer a square wave, because
there is less variation in the absolute current, and therefore less
variation in heating. This means less thermal and physical stress, and
a longer life for the same power output.
But I agree that the question is if the load cares or not. For many
purposes, a square wave should be better (though DC would be best), but
most devices are specified, optimised and tested with AC (at least
roughly sinusoidal) inputs.
David Brown
<snip>
Ops, looks like you've blown a fuse again. That can't be good for your
heart at your age. Perhaps you should ask the nurse to up your valium
dosage (or is it lithium?).
Rod Speed
> David Lesher wrote
>> David Brown <da...@westcontrol.removethisbit.com> wrote
>>> So you now agree that there is no such thing as a "TRUE sine wave" output from an UPS? It's a pity that you then
>>> contradict yourself /again/ later on.
>> Well, I know of one design that I'd call same; but not sure you will. The best ferro-resonant UPS's are damn close.
>> Of course, such are neither common or inexpensive.
> I've no argument that you can generate very close to sine waves
And that is clearly what the OP was talking
about when he used the term TRUE sine wave.
> - for most practical purposes, devices like these are effectively sinusoidal with no harmonics that you normally need
> to consider.
What matters is that they are at least as close
to a sine wave as the mains they replace.
> Every application has its requirements for how good a sine wave it needs,
What matters with a UPS is that the sine wave is at
least as good harmonics wise as the mains it replaces.
> and you can get as close as you like (until you are limited by fundamental things like thermal noise).
You arent necessarily even limited by that.
> I've just been arguing about rodbot's descriptions of UPS outputs as "true sine wave",
I never ever used that term myself, you silly little
pathological liar/pathetic excuse for a lying bullshit artist.
> and his claims that things like rotary converters and the mains supply produce /pure/ sine waves with absolutely no
> harmonics.
Everyone can see for themselves that I never ever said
anything even remotely resembling anything like that, and
in fact never ever use the word PURE sine wave at all, you silly
little pathological liar/pathetic excuse for a lying bullshit artist.
>> [But then the line itself is never purely sinusoidal, either; it come with flaws such as spikes and dropouts...]
>> The real question is: does the load care if it's not? If all loads are switchers, usually not at all. Linear
>> wall-warts may. Incandescent lamps won't have a clue.
> Incandescent lamps /will/ care - they will prefer a square wave,
Wrong, as always.
> because there is less variation in the absolute current, and therefore less variation in heating.
Mindlessly silly. They dont give a flying red fuck about the current being less
than the peak current. In fact that increases the life of the filament, fool.
> This means less thermal and physical stress,
Only in your pathetic little pig ignorant fantasyland.
> and a longer life for the same power output.
Only in your pathetic little pig ignorant fantasyland.
They in fact prefer a less than sudden current rise, if only
because you dont get as much magnetic field effect with
the coiled filaments etc and less thermal shock with the
initial turn on when the filament cold resistance is lowest.
> But I agree that the question is if the load cares or not. For many purposes, a square wave should be better
Fuck all in fact.
> (though DC would be best),
Try sticking that into a switcher and see how well it works.
> but most devices are specified, optimised and tested with AC (at least roughly sinusoidal) inputs.
You quite sure you aint one of those rocket scientist silly little
pathological liars/pathetic excuses for a lying bullshit artist ?
Rod Speed
David Brown desperately attempted to bullshit and lie its way out of its predicament
and fooled absolutely no one at all, as always.
David Brown
> David Brown wrote
>> David Lesher wrote
>>> David Brown <da...@westcontrol.removethisbit.com> wrote
>
>>>> So you now agree that there is no such thing as a "TRUE sine
>>>> wave" output from an UPS? It's a pity that you then contradict
>>>> yourself /again/ later on.
>
>>> Well, I know of one design that I'd call same; but not sure you
>>> will. The best ferro-resonant UPS's are damn close. Of course,
>>> such are neither common or inexpensive.
>
>> I've no argument that you can generate very close to sine waves
>
> And that is clearly what the OP was talking about when he used the
> term TRUE sine wave.
>
It seems unlikely that you'll ever understand what "true" means in this
context. I know perfectly well what sort of quality sine waves
real-world UPS's can generate, but when you insist on using a precise
technical expression like "true sine wave", even emphasising the "true"
with capitals, you need to be corrected.
>> - for most practical purposes, devices like these are effectively
>> sinusoidal with no harmonics that you normally need to consider.
>
> What matters is that they are at least as close to a sine wave as the
> mains they replace.
>
In the case of specialised UPS's as mentioned by the previous poster
(you snippet the quotation), the waves should be a lot /better/ than
typical mains supplies.
Mains varies a lot in quality - the voltage can vary quite substantially
from average ratings, you get spikes and droops, phase distortions,
harmonics, and short-term variations from the ideal 50 (or 60) Hz.
>> Every application has its requirements for how good a sine wave it
>> needs,
>
> What matters with a UPS is that the sine wave is at least as good
> harmonics wise as the mains it replaces.
>
No, what matters is that it is good enough for the application.
>> and you can get as close as you like (until you are limited by
>> fundamental things like thermal noise).
>
> You arent necessarily even limited by that.
>
Those pesky fundamental physical limitations causing you trouble again?
Yes, you are limited be thermal noise. You can reduce the thermal
noise greatly by cooling, of course, but you can't eliminate it
entirely. And even if you want to run your system in liquid helium,
you've still got quantum effects.
>
>>> The real question is: does the load care if it's not? If all
>>> loads are switchers, usually not at all. Linear wall-warts may.
>>> Incandescent lamps won't have a clue.
>
>> Incandescent lamps /will/ care - they will prefer a square wave,
>
> Wrong, as always.
>
>> because there is less variation in the absolute current, and
>> therefore less variation in heating.
>
> Mindlessly silly. They dont give a flying red fuck about the current
> being less than the peak current. In fact that increases the life of
> the filament, fool.
>
>> This means less thermal and physical stress,
>
> Only in your pathetic little pig ignorant fantasyland.
>
>> and a longer life for the same power output.
>
> Only in your pathetic little pig ignorant fantasyland.
>
> They in fact prefer a less than sudden current rise, if only because
> you dont get as much magnetic field effect with the coiled filaments
> etc and less thermal shock with the initial turn on when the filament
> cold resistance is lowest.
>
There are three issues with changes in current. One is the initial
startup heating and thermal shock from a cold filament. That's the
biggest shock, and the most likely time to blow the bulb. The sine wave
reduces that slightly on average compared to a square wave - but for
each time the light switch is activated, the actual initial inrush
current will depend on where you are in the 50 Hz cycle. And of course,
switch bounce in your average light switch will ensure that each time
you turn the light on, it will be hit by several full voltage blasts.
Then you've got the effect of the I^2R heating. With AC, this will vary
between zero and full effect 100 times per second, leading to changes in
the temperature and thus thermal stresses at this rate - the thermal
mass of the filament is not enough to smooth out these changes. With a
square wave, the absolute current is the same except for brief pause
when the polarity changes. These pauses are much shorter than for a
sinusoidal current, and the current between the pauses is far more
consistent. Thus there is much less thermal stress.
You also mentioned changes in the magnetic field as the current changes.
Yes, this will happen - but the inductance of the filament coil is
very low, and the rate of current change is not /that/ high even in a
square wave output UPS (we are talking real-world supplies here, which
have at least some passive filtering). The magnetic field changes have
two effects in the filament - one is to oppose the current changes
(increasing the time when the square wave is not at its consistent full
current), and the other is physical forces on the filament itself from
its magnetic field. Both of these will be very minor effects.
>> But I agree that the question is if the load cares or not. For
>> many purposes, a square wave should be better
>
> Fuck all in fact.
>
>> (though DC would be best),
>
> Try sticking that into a switcher and see how well it works.
>
That depends entirely on what you are using. Many power supplies have a
very simple bridge rectifier on the input - they'll be as happy with DC
as AC. Others depend on the AC - an obvious example is if you have a
transformer.
To take proper advantage of a DC system requires a DC supply and
DC-optimised power supplies - clearly a change in the way the
electricity supply works. This would make it impractical for most
purposes - no matter what it's benefits are, it would be incompatible
with existing systems. It would only really be practical for things
like large server setups.
DC Power supplies that work with AC inputs must first rectify the AC to
DC (some will have a transformer before this point, but they are less
common now), before generating the regulated low voltage DC supplies.
If you have a DC input, you can avoid that part - saving costs, size,
and wasted energy. You also avoid all power factor issues.
Rod Speed
> Rod Speed wrote
>> David Brown wrote
>>> David Lesher wrote
>>>> David Brown <da...@westcontrol.removethisbit.com> wrote
>>>>> So you now agree that there is no such thing as a "TRUE sine
>>>>> wave" output from an UPS? It's a pity that you then contradict
>>>>> yourself /again/ later on.
>>>> Well, I know of one design that I'd call same; but not sure you
>>>> will. The best ferro-resonant UPS's are damn close. Of course,
>>>> such are neither common or inexpensive.
>>> I've no argument that you can generate very close to sine waves
>> And that is clearly what the OP was talking about when he used the
>> term TRUE sine wave.
> It seems unlikely that you'll ever understand what "true" means in this context.
Never ever could bullshit and lie its way out of a wet paper bag.
What he said is clearly what it means, fuckwit.
> I know perfectly well what sort of quality sine waves real-world UPS's can generate, but when you insist on using a
> precise technical expression like "true sine wave",
Taint a precise technical expression, fuckwit.
> even emphasising the "true" with capitals,
Only did that because you flagrantly dishonestly slithered off to PURE sine waves, fuckwit.
> you need to be corrected.
Pity all you ever did was flaunt your complete pig ignorance of what the OP was talking about.
>>> - for most practical purposes, devices like these are effectively
>>> sinusoidal with no harmonics that you normally need to consider.
>> What matters is that they are at least as close to a sine wave as the mains they replace.
> In the case of specialised UPS's as mentioned by the previous poster (you snippet the quotation),
You're lying, as always. I never ever snipped a damned thing you silly little pathological liar.
> the waves should be a lot /better/ than typical mains supplies.
Completely and utterly irrelevant to your desperate attempts to bullshit and lie
your way out of your predicament that fools absolutely no one at all, as always.
> Mains varies a lot in quality - the voltage can vary quite substantially from average ratings, you get spikes and
> droops, phase distortions, harmonics, and short-term variations from the ideal 50 (or 60) Hz.
No news to anyone, you pathetic excuse for a lying bullshit artist.
>>> Every application has its requirements for how good a sine wave it needs,
>> What matters with a UPS is that the sine wave is at least as good harmonics wise as the mains it replaces.
> No,
Yep.
> what matters is that it is good enough for the application.
Wrong, as always.
>>> and you can get as close as you like (until you are limited by fundamental things like thermal noise).
>> You arent necessarily even limited by that.
> Those pesky fundamental physical limitations causing you trouble again?
Nope.
> Yes, you are limited be thermal noise.
Nope.
> You can reduce the thermal noise greatly by cooling, of course, but you can't eliminate it entirely.
Dont need to when its a fart in the bath with any practical UPS.
> And even if you want to run your system in liquid helium, you've still got quantum effects.
Never ever could bullshit and lie its way out of a wet paper bag.
>>>> The real question is: does the load care if it's not? If all
>>>> loads are switchers, usually not at all. Linear wall-warts may.Incandescent lamps won't have a clue.
>>> Incandescent lamps /will/ care - they will prefer a square wave,
>> Wrong, as always.
>>> because there is less variation in the absolute current, and therefore less variation in heating.
>> Mindlessly silly. They dont give a flying red fuck about the current being less than the peak current. In fact that
>> increases the life of the filament, fool.
>>> This means less thermal and physical stress,
>> Only in your pathetic little pig ignorant fantasyland.
>>> and a longer life for the same power output.
>> Only in your pathetic little pig ignorant fantasyland.
>> They in fact prefer a less than sudden current rise, if only because you dont get as much magnetic field effect with
>> the coiled filaments etc and less thermal shock with the initial turn on when the filament cold resistance is lowest.
> There are three issues with changes in current.
Nope.
> One is the initial startup heating and thermal shock from a cold filament. That's the biggest shock, and the most
> likely time to blow the bulb.
And blows a fucking great hole in your stupid pig ignorant claim that
incandescents last longer with a square wave than a sine wave.
> The sine wave reduces that slightly on average compared to a square wave
So your original claim is just plain wrong.
> - but for each time the light switch is activated, the actual initial inrush current will depend on where you are in
> the 50 Hz cycle.
Still better than with a square wave where it can only be on or off, fuckwit.
> And of course, switch bounce in your average light switch will ensure that
> each time you turn the light on, it will be hit by several full voltage blasts.
Still better than with a square wave where it can only be on or off, fuckwit.
> Then you've got the effect of the I^2R heating. With AC, this will vary between zero and full effect 100 times per
> second, leading to changes in the temperature
Wrong, as always. The thermal inertia of the filament completely swamps that, fuckwit.
> and thus thermal stresses at this rate - the thermal mass of the filament is not enough to smooth out these changes.
Wrong, as always. The light output of an incandescent
isnt even modulated at 100Hz, so the thermal inertia
completely swamps that effect, fuckwit.
> With a square wave, the absolute current is the same except for brief pause when the polarity changes. These pauses
> are much shorter than for a sinusoidal current, and the current between the pauses is far more consistent. Thus there
> is much less thermal stress.
How odd that you dont actually get any 100Hz component in the light output, fuckwit.
> You also mentioned changes in the magnetic field as the current changes. Yes, this will happen - but the inductance of
> the filament coil is very low,
And the current is very high, particularly when its cold.
> and the rate of current change is not /that/ high
How odd that you can actually see the filament jerk under a microscope, fuckwit.
> even in a square wave output UPS (we are talking real-world supplies here, which have at least some passive
> filtering).
Not enough to matter, fuckwit.
> The magnetic field changes have two effects in the filament - one is to oppose the current changes (increasing the
> time when the square wave is not at its consistent full current), and the other is physical forces on the filament
> itself from its magnetic field. Both of these will be very minor effects.
How odd that you can actually see the filament jerk under
a microscope, and they almost always fail on turnon, fuckwit.
>>> But I agree that the question is if the load cares or not. For many purposes, a square wave should be better
>> Fuck all in fact.
>>> (though DC would be best),
>> Try sticking that into a switcher and see how well it works.
> That depends entirely on what you are using.
Not with a switcher it wont.
> Many power supplies have a very simple bridge rectifier on the input - they'll be as happy with DC as AC.
Pity about the standby rails.
> Others depend on the AC - an obvious example is if you have a transformer.
<reams of your desperate attempt to bullshit your way out of your predicament
that fools absolutely no one at all, as always, flushed where it belongs>
David Brown
Rod Speed
> <snip>
Pathetic.
John Turco
>
> I was sitting at my desk yesterday during a storm when there was a
> split-second power outage. Despite the fact that my battery shows all 5
> lights lit, the computer died.
>
> Is there a better brand to use than APC? Can the battery be sub-par
> even though the test lights say it is OK? What have others of you chosen?
>
> Ken K
Personally, I've been running a Tripp Lite "Internet Office INTERNET900U"
(900VA, 480 watts) UPS, the past month and a half or so. It features a
whopping 12 AC outlets (6 battery-supported, 6 surge suppression-only);
which, to my knowledge, no other manufacturer can match.
Previously, I'd used an APC "Back-UPS LS 700VA" (BP700UC; 700VA, 410w),
for around 7.5 years. This unit has a "mere" total of seven outlets (4
and 3, respectively). I couldn't plug everything into it, and hence,
also needed a separate power strip/surge suppressor.
Good luck!
--
Cordially,
John Turco <jt...@concentric.net>
Paintings Pain and Pun <http://laughatthepain.blogspot.com>