Sign in with
Sign up | Sign in
Your question

DLP and Power Failure

Last response: in Home Theatre
Share
Anonymous
December 13, 2004 8:49:58 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

When one turns off a DLP set, the fan continues to run for about 60 seconds
afterward. I wonder what would happen if there were a power failure while
watching a DLP set. Without the fan running to dissipate any residual heat what
would happen to the lamp assembly?

More about : dlp power failure

Anonymous
December 14, 2004 12:45:18 AM

Archived from groups: alt.tv.tech.hdtv (More info?)

Generally, it is not the power failure that is likely to damage the unit
(it'll just take longer to cool down) but the surge on restart or multiple
false restarts until the power stabilizes. I have a LCD that also has a
cooling circuit. I power my unit thru an UPS.

YMMV

--
"Sleep is a poor substitute for coffee."
- Anon
"Bill Oertell" <notoertell@pacbell.net> wrote in message
news:10rshm6ldbb782a@news.supernews.com...
> When one turns off a DLP set, the fan continues to run for about 60
> seconds
> afterward. I wonder what would happen if there were a power failure while
> watching a DLP set. Without the fan running to dissipate any residual
> heat what
> would happen to the lamp assembly?
>
>
Anonymous
December 14, 2004 1:12:14 AM

Archived from groups: alt.tv.tech.hdtv (More info?)

"MrMike6by9" <MrMike6by9@hotmail.com> wrote in message
news:IMudnZvgnoRdziPcRVn-jg@comcast.com...
> Generally, it is not the power failure that is likely to damage the unit
> (it'll just take longer to cool down) but the surge on restart or multiple
> false restarts until the power stabilizes. I have a LCD that also has a
> cooling circuit. I power my unit thru an UPS.

All DLP and LCD units that I know of have temperature sensors and/or delays
to prevent repetitive start cycles when the lamp is hot. Interrupting the
cool down cycle with a power outage will not damage the lamp. Trying to
strike the arc when the lamp is already hot will, but I know of no consumer
units that will allow this. There is nothing wrong with having the unit on
a UPS, but it really is not necessary.

In general, the best rule is to minimize start cycles. This is the single
best way to extend the life of a lamp, other than not using it at all. The
occasional power outage is hardly going to make much difference. Good surge
protection is a good idea and a UPS certainly can't hurt.

Leonard
Related resources
Anonymous
December 14, 2004 6:53:37 AM

Archived from groups: alt.tv.tech.hdtv (More info?)

"Leonard Caillouet" <no@no.com> wrote in message
news:_Ssvd.4423$jn.1861@lakeread06...
>
> "MrMike6by9" <MrMike6by9@hotmail.com> wrote in message
> news:IMudnZvgnoRdziPcRVn-jg@comcast.com...
>> Generally, it is not the power failure that is likely to damage the unit
>> (it'll just take longer to cool down) but the surge on restart or
>> multiple
>> false restarts until the power stabilizes. I have a LCD that also has a
>> cooling circuit. I power my unit thru an UPS.
>
> All DLP and LCD units that I know of have temperature sensors and/or
> delays
> to prevent repetitive start cycles when the lamp is hot. Interrupting the
> cool down cycle with a power outage will not damage the lamp. Trying to
> strike the arc when the lamp is already hot will, but I know of no
> consumer
> units that will allow this. There is nothing wrong with having the unit
> on
> a UPS, but it really is not necessary.
>
> In general, the best rule is to minimize start cycles. This is the single
> best way to extend the life of a lamp, other than not using it at all.
> The
> occasional power outage is hardly going to make much difference. Good
> surge
> protection is a good idea and a UPS certainly can't hurt.
>
> Leonard
>

Leonard,

Consider the situation where you're watching tv but you decide you're going
to do something else for a while and then come back. How long does "a
while" need to be such that it is better to turn the tv off while you're
away and then restart when you come back? For example, if I'm not going to
watch tv for 30 minutes should I turn it off or leave it on? Where's the
cutoff? I'm guessing you don't have any hard numbers on this but go ahead
and wager a guess.

Thanks,

Brad
Anonymous
December 14, 2004 9:16:56 AM

Archived from groups: alt.tv.tech.hdtv (More info?)

"Brad Griffis" <bradgriffis@hotmail.com> wrote in message
news:5ttvd.32350$Rf1.31095@newssvr19.news.prodigy.com...
>
> "Leonard Caillouet" <no@no.com> wrote in message
> news:_Ssvd.4423$jn.1861@lakeread06...
> >
> > "MrMike6by9" <MrMike6by9@hotmail.com> wrote in message
> > news:IMudnZvgnoRdziPcRVn-jg@comcast.com...
> >> Generally, it is not the power failure that is likely to damage the
unit
> >> (it'll just take longer to cool down) but the surge on restart or
> >> multiple
> >> false restarts until the power stabilizes. I have a LCD that also has a
> >> cooling circuit. I power my unit thru an UPS.
> >
> > All DLP and LCD units that I know of have temperature sensors and/or
> > delays
> > to prevent repetitive start cycles when the lamp is hot. Interrupting
the
> > cool down cycle with a power outage will not damage the lamp. Trying to
> > strike the arc when the lamp is already hot will, but I know of no
> > consumer
> > units that will allow this. There is nothing wrong with having the unit
> > on
> > a UPS, but it really is not necessary.
> >
> > In general, the best rule is to minimize start cycles. This is the
single
> > best way to extend the life of a lamp, other than not using it at all.
> > The
> > occasional power outage is hardly going to make much difference. Good
> > surge
> > protection is a good idea and a UPS certainly can't hurt.
> >
> > Leonard
> >
>
> Leonard,
>
> Consider the situation where you're watching tv but you decide you're
going
> to do something else for a while and then come back. How long does "a
> while" need to be such that it is better to turn the tv off while you're
> away and then restart when you come back? For example, if I'm not going
to
> watch tv for 30 minutes should I turn it off or leave it on? Where's the
> cutoff? I'm guessing you don't have any hard numbers on this but go ahead
> and wager a guess.
>
> Thanks,
>
> Brad

Brad,

You are correct, I have no hard numbers, just the impressions that I get
from conversations with tech reps from the manufacturers. They all say that
the aging of the lamps is much greater in start-up, where a series of high
voltage pulses is used. After it is running the voltage drops to hundreds
of volts. I would guess that in normal use a good rule of thumb is maybe an
hour or two.

Leonard
Anonymous
December 14, 2004 11:46:46 AM

Archived from groups: alt.tv.tech.hdtv (More info?)

Leonard Caillouet wrote:

> ...There is nothing wrong with having the unit on
> a UPS, but it really is not necessary.
>
> In general, the best rule is to minimize start cycles. ...

Leonard,

And of course having a UPS will eliminate those restarts associated
with brief power losses,
December 15, 2004 4:03:41 AM

Archived from groups: alt.tv.tech.hdtv (More info?)

In article <41beeec5$1@news101.his.com>,
saltidawgNOSPAM@users.sourceforge.net says...
> Leonard Caillouet wrote:
>
> > ...There is nothing wrong with having the unit on
> > a UPS, but it really is not necessary.
> >
> > In general, the best rule is to minimize start cycles. ...
>
> Leonard,
>
> And of course having a UPS will eliminate those restarts associated
> with brief power losses,

Just how many power failures do you experience while watching TV!? I've
had maybe 3 in 10 years...

In my case at least it really is not necessary. Advocating getting a UPS
to prevent 3 unnecessary power cycles per decade is demented.
December 15, 2004 4:08:21 AM

Archived from groups: alt.tv.tech.hdtv (More info?)

In article <WZzvd.4696$jn.4520@lakeread06>, no@no.com says...
>
> "Brad Griffis" <bradgriffis@hotmail.com> wrote in message
> news:5ttvd.32350$Rf1.31095@newssvr19.news.prodigy.com...
> >
> > "Leonard Caillouet" <no@no.com> wrote in message
> > news:_Ssvd.4423$jn.1861@lakeread06...
> > >
> > > "MrMike6by9" <MrMike6by9@hotmail.com> wrote in message
> > > news:IMudnZvgnoRdziPcRVn-jg@comcast.com...
> > >> Generally, it is not the power failure that is likely to damage the
> unit
> > >> (it'll just take longer to cool down) but the surge on restart or
> > >> multiple
> > >> false restarts until the power stabilizes. I have a LCD that also has a
> > >> cooling circuit. I power my unit thru an UPS.
> > >
> > > All DLP and LCD units that I know of have temperature sensors and/or
> > > delays
> > > to prevent repetitive start cycles when the lamp is hot. Interrupting
> the
> > > cool down cycle with a power outage will not damage the lamp. Trying to
> > > strike the arc when the lamp is already hot will, but I know of no
> > > consumer
> > > units that will allow this. There is nothing wrong with having the unit
> > > on
> > > a UPS, but it really is not necessary.
> > >
> > > In general, the best rule is to minimize start cycles. This is the
> single
> > > best way to extend the life of a lamp, other than not using it at all.
> > > The
> > > occasional power outage is hardly going to make much difference. Good
> > > surge
> > > protection is a good idea and a UPS certainly can't hurt.
> > >
> > > Leonard
> > >
> >
> > Leonard,
> >
> > Consider the situation where you're watching tv but you decide you're
> going
> > to do something else for a while and then come back. How long does "a
> > while" need to be such that it is better to turn the tv off while you're
> > away and then restart when you come back? For example, if I'm not going
> to
> > watch tv for 30 minutes should I turn it off or leave it on? Where's the
> > cutoff? I'm guessing you don't have any hard numbers on this but go ahead
> > and wager a guess.
> >
> > Thanks,
> >
> > Brad
>
> Brad,
>
> You are correct, I have no hard numbers, just the impressions that I get
> from conversations with tech reps from the manufacturers. They all say that
> the aging of the lamps is much greater in start-up, where a series of high
> voltage pulses is used. After it is running the voltage drops to hundreds
> of volts. I would guess that in normal use a good rule of thumb is maybe an
> hour or two.

The same is true of cars, computers, and light bulbs. But its foolish to
leave them all on all the time. As long as you aren't sitting there
flicking it on and off you'll be fine. You aren't going to squeeze an
extra year out of the bulb because you leave it on to avoid power
cycling it when you take your kids to soccer practice.
Anonymous
December 15, 2004 4:08:22 AM

Archived from groups: alt.tv.tech.hdtv (More info?)

"42" <nospam@nospam.com> wrote in message
news:MPG.1c292e6b911588d8989927@shawnews...
> In article <WZzvd.4696$jn.4520@lakeread06>, no@no.com says...
> >
> > "Brad Griffis" <bradgriffis@hotmail.com> wrote in message
> > news:5ttvd.32350$Rf1.31095@newssvr19.news.prodigy.com...
> > >
> > > "Leonard Caillouet" <no@no.com> wrote in message
> > > news:_Ssvd.4423$jn.1861@lakeread06...
> > > >
> > > > "MrMike6by9" <MrMike6by9@hotmail.com> wrote in message
> > > > news:IMudnZvgnoRdziPcRVn-jg@comcast.com...
> > > >> Generally, it is not the power failure that is likely to damage the
> > unit
> > > >> (it'll just take longer to cool down) but the surge on restart or
> > > >> multiple
> > > >> false restarts until the power stabilizes. I have a LCD that also
has a
> > > >> cooling circuit. I power my unit thru an UPS.
> > > >
> > > > All DLP and LCD units that I know of have temperature sensors and/or
> > > > delays
> > > > to prevent repetitive start cycles when the lamp is hot.
Interrupting
> > the
> > > > cool down cycle with a power outage will not damage the lamp.
Trying to
> > > > strike the arc when the lamp is already hot will, but I know of no
> > > > consumer
> > > > units that will allow this. There is nothing wrong with having the
unit
> > > > on
> > > > a UPS, but it really is not necessary.
> > > >
> > > > In general, the best rule is to minimize start cycles. This is the
> > single
> > > > best way to extend the life of a lamp, other than not using it at
all.
> > > > The
> > > > occasional power outage is hardly going to make much difference.
Good
> > > > surge
> > > > protection is a good idea and a UPS certainly can't hurt.
> > > >
> > > > Leonard
> > > >
> > >
> > > Leonard,
> > >
> > > Consider the situation where you're watching tv but you decide you're
> > going
> > > to do something else for a while and then come back. How long does "a
> > > while" need to be such that it is better to turn the tv off while
you're
> > > away and then restart when you come back? For example, if I'm not
going
> > to
> > > watch tv for 30 minutes should I turn it off or leave it on? Where's
the
> > > cutoff? I'm guessing you don't have any hard numbers on this but go
ahead
> > > and wager a guess.
> > >
> > > Thanks,
> > >
> > > Brad
> >
> > Brad,
> >
> > You are correct, I have no hard numbers, just the impressions that I get
> > from conversations with tech reps from the manufacturers. They all say
that
> > the aging of the lamps is much greater in start-up, where a series of
high
> > voltage pulses is used. After it is running the voltage drops to
hundreds
> > of volts. I would guess that in normal use a good rule of thumb is
maybe an
> > hour or two.
>
> The same is true of cars, computers, and light bulbs. But its foolish to
> leave them all on all the time. As long as you aren't sitting there
> flicking it on and off you'll be fine. You aren't going to squeeze an
> extra year out of the bulb because you leave it on to avoid power
> cycling it when you take your kids to soccer practice.

Light bulbs are not started with high voltage pulses. I suspect if you
started the unit an extra time each day over the life of a lamp you would
affect its longevity somewhat. To what degree is unclear, but since every
tech rep that I have discussed the matter with emphasize that the start
cycle on these lamps is where most of the life shortening occurs, I would be
conservative on the matter.

Leonard
Anonymous
December 15, 2004 11:16:50 AM

Archived from groups: alt.tv.tech.hdtv (More info?)

42 wrote:

> In my case at least it really is not necessary. Advocating getting a UPS
> to prevent 3 unnecessary power cycles per decade is demented.

I don't see where anyone advocated any such thing. Some of us
experience brief outages quite frequently. Failure to address this
issue in such a situation would seem "demented." YMMV :-)
Anonymous
December 15, 2004 9:51:49 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

"42" <nospam@nospam.com> wrote in message
news:MPG.1c292d4e1eca568989926@shawnews...
>
> Just how many power failures do you experience while watching TV!? I've
> had maybe 3 in 10 years...
>
> In my case at least it really is not necessary. Advocating getting a UPS
> to prevent 3 unnecessary power cycles per decade is demented.

Aren't you lucky? Too bad your experience isn't necessarily shared the rest
of us.
December 16, 2004 2:56:51 AM

Archived from groups: alt.tv.tech.hdtv (More info?)

In article <41c03940@news101.his.com>,
saltidawgNOSPAM@users.sourceforge.net says...
> 42 wrote:
>
> > In my case at least it really is not necessary. Advocating getting a UPS
> > to prevent 3 unnecessary power cycles per decade is demented.
>
> I don't see where anyone advocated any such thing. Some of us
> experience brief outages quite frequently. Failure to address this
> issue in such a situation would seem "demented." YMMV :-)

Sure. As I said "In my case it really is not neccessary."

And I think *most* people's cases mirror mine. But I'm sure there are
some of you out there who experience them quite frequently... but even 1
a month... you'll probably spend more on your UPS than you would on the
extra lamps you'll need as a result of extra cycling. If you are
experiencing breif power failures on a weekly basis... sure... but
that's REALLY severe and unusual.
Anonymous
December 16, 2004 3:55:35 AM

Archived from groups: alt.tv.tech.hdtv (More info?)

Manufacturer data sheets for lamps say life expectancy is
inversely proportional to voltage and to hours of operation.
Increase in voltage causes a decrease in life expectancy by an
exponential factor of about 12. Simply increase line voltage
from 120 to 128 to get only 1/2 the life from a light bulb.
Voltage determines life expectancy.

However many have turned on a bulb, saw what looked like an
explosive flash - and that alone was sufficient proof that
power cycling causes failure. Reality. Did they first notice
blackness inside glass? If not, then they were making
conclusions with insufficient facts. That blackness comes
from hours of operation. Once the filament is so severely
damaged as to even blacken glass, then a gentle force called
power cycling can cause filament failure. A light bulb that
has less than 10 hours left easily can be destroyed even by a
power on. But power cycling only causes light bulb damage
when one does not first learn how light bulbs fail. That
failure was first caused by hours of operation.

Numerical relationship and bulb life expectancy is better
found in an IES Lighting Handbook - an industry standard.
Power cycling is just not a parameter because power cycling is
not destructive.

Facts are demonstrated every day. If power cycling was so
destructive, then the bulb most likely to burn out is the
orange bulb that is blinking all night. Reality - the bulbs
more likely to fail are red and green - the bulbs that power
cycle less and that are powered for more hours. Power cycling
causes damage only when one makes speculation based only upon
what they saw, saw too little, AND without the all so
necessary underlying theory.

These principles were taught to all in junior high school
science. To discover a fact, one must have both the
underlying theory AND experimental evidence. Anything less is
called junk science reasoning. Junk science reasoning is why
many 'feel' power cycling a light bulb causes premature
failure. Power cycling does not adversely effect incandescent
bulb life expectancy.

Component manufacturers suggest life expectancy in hours of
operation. Where some components have life expectancy due to
cycling (ie power switches), then that number also is listed.

Can power cycling be destructive? Some components do have
limits. And then we confront those parts with seven power
cycles every day - a number. How long will it last? Probably
20 or 40 years if heavily power cycled multiple times every
day. IOW power cycling becomes completely irrelevant once we
put up the numbers. Speculation without the perspective of
numbers is a symptom of junk science. Junk science reasoning
avoids numbers (ie manufacturer data sheets).

The incandescent light bulb is not prematurely damaged by
power cycling. That speculation was based upon junk science
reasoning. Both by how the conclusion was obtained (no
comprehension of underlying principles - the theory) AND by
not providing numbers.

BTW, a plug-in UPS could (not likely) cause premature TV
failure because the plug-in UPS in battery backup mode may
output too much power at odd harmonics of 60 hz. Plug-in
UPSes output their dirtiest power when in battery backup mode
with sine waves at 180 hz, 300 hz, 420 hz, etc - which may
cause increased and destructive heating inside a transformer.

When does the plug-in UPS output cleanest power? When power
relay connects appliance directly to AC mains. Will a UPS
protect a TV from power cycling damage? No. We have
provided the numbers. A UPS might eliminate maybe three power
offs. A big NO because numbers make it that obvious.

Even worse, the UPS in battery backup mode could adversely
affect that TV (depending on the TV design). Does TV get
standby power through a line transformer? If yes, then the
plug-in UPS could promote a TV failure.

Again, one must first learn the principles. Does that UPS
output a modified sine wave? Yes. 'Dirty' electricity is
chock full of sine waves. Not all those sine waves are TV
friendly. Want a better answer? Lets see the schematics, the
numbers, and other important details. First we need facts -
not junk science speculations.

Is power cycling destructive? Most often, only junk science
says leave it on. Credibility. Did he provide numbers?
Those who claim so much damage from power cycling constantly
avoid numbers to promote the myth.

42 wrote:
> In article <WZzvd.4696$jn.4520@lakeread06>, no@no.com says...
>> You are correct, I have no hard numbers, just the impressions that
>> I get from conversations with tech reps from the manufacturers.
>> They all say that the aging of the lamps is much greater in
>> start-up, where a series of high voltage pulses is used. After it
>> is running the voltage drops to hundreds of volts. I would guess
>> that in normal use a good rule of thumb is maybe an hour or two.
>
> The same is true of cars, computers, and light bulbs. But its foolish to
> leave them all on all the time. As long as you aren't sitting there
> flicking it on and off you'll be fine. You aren't going to squeeze an
> extra year out of the bulb because you leave it on to avoid power
> cycling it when you take your kids to soccer practice.
Anonymous
December 16, 2004 10:38:26 AM

Archived from groups: alt.tv.tech.hdtv (More info?)

Comments imbedded debunking w_toms out of context condescending bullshit.

"w_tom" <w_tom1@hotmail.com> wrote in message
news:41C12357.D3AE61BD@hotmail.com...
> Manufacturer data sheets for lamps say life expectancy is
> inversely proportional to voltage and to hours of operation.
> Increase in voltage causes a decrease in life expectancy by an
> exponential factor of about 12. Simply increase line voltage
> from 120 to 128 to get only 1/2 the life from a light bulb.
> Voltage determines life expectancy.

Once again, w_tom takes a bit of truth and applies it out of context...

All current consumer DLP sets operate with regulated power supplies that
keep line variations from affecting the lamp and other circuits. There will
be NO EFFECT on lamp life due to line voltage variations of this kind.

> However many have turned on a bulb, saw what looked like an
> explosive flash - and that alone was sufficient proof that
> power cycling causes failure. Reality. Did they first notice
> blackness inside glass? If not, then they were making
> conclusions with insufficient facts. That blackness comes
> from hours of operation. Once the filament is so severely
> damaged as to even blacken glass, then a gentle force called
> power cycling can cause filament failure. A light bulb that
> has less than 10 hours left easily can be destroyed even by a
> power on. But power cycling only causes light bulb damage
> when one does not first learn how light bulbs fail. That
> failure was first caused by hours of operation.

Curious that all of the major manufacturers say the same thing, that hours
of use AND start cycles affect the life of a lamp. Restarting the lamp hot
can be very destructive and this is why they all have temp sensors that keep
this from happening, and/or turn-on delays. The fact that the arc is struck
with high voltage pulses, then the voltage drops to run the lamp is the
reason.

> Numerical relationship and bulb life expectancy is better
> found in an IES Lighting Handbook - an industry standard.
> Power cycling is just not a parameter because power cycling is
> not destructive.

Says you. Sony, Mitsubishi, itachi, Yamaha, Marantz, Runco, NEC, Optoma
(Coretronic) all say otherwise. Power cycling on many lamps may not make a
difference, but in this application they do.

> Facts are demonstrated every day. If power cycling was so
> destructive, then the bulb most likely to burn out is the
> orange bulb that is blinking all night. Reality - the bulbs
> more likely to fail are red and green - the bulbs that power
> cycle less and that are powered for more hours. Power cycling
> causes damage only when one makes speculation based only upon
> what they saw, saw too little, AND without the all so
> necessary underlying theory.

Seems like the folks that have actual experience in this application and who
have done extensive testing on lamp failures and life expectancy come to one
conclusion, and you, more likely speculating than they, come to another.
Tell us w_tom, what do you do and what qualifications do you have to dispute
the vendors who build and supply the products we are talking about?

> These principles were taught to all in junior high school
> science. To discover a fact, one must have both the
> underlying theory AND experimental evidence. Anything less is
> called junk science reasoning. Junk science reasoning is why
> many 'feel' power cycling a light bulb causes premature
> failure. Power cycling does not adversely effect incandescent
> bulb life expectancy.

More condescending bullshit. OTOH, students are taught, starting in
elementary school, to pay attention to the discussion, and not to take
things out of context. Somewhere along the way, usually in high school or
college, most students learn that making an arguament based on poorly
founded assumptions and using a different context than the discussion makes
one look like a fool. Apparently some never learn.

WE ARE NOT TALKING ABOUT CONVENTIONAL LIGHT BULBS!

> Component manufacturers suggest life expectancy in hours of
> operation. Where some components have life expectancy due to
> cycling (ie power switches), then that number also is listed.
>
> Can power cycling be destructive? Some components do have
> limits. And then we confront those parts with seven power
> cycles every day - a number. How long will it last? Probably
> 20 or 40 years if heavily power cycled multiple times every
> day. IOW power cycling becomes completely irrelevant once we
> put up the numbers. Speculation without the perspective of
> numbers is a symptom of junk science. Junk science reasoning
> avoids numbers (ie manufacturer data sheets).

You have repeatedly assumed that everything that matters is specified by
manufacturers and industry standards. You obvioulsly don't have much
experience with consumer electronics, where very little is actually
available in terms of component and application data.

> The incandescent light bulb is not prematurely damaged by
> power cycling. That speculation was based upon junk science
> reasoning. Both by how the conclusion was obtained (no
> comprehension of underlying principles - the theory) AND by
> not providing numbers.

You go on and on about a topic that is not what we were discussing...

> BTW, a plug-in UPS could (not likely) cause premature TV
> failure because the plug-in UPS in battery backup mode may
> output too much power at odd harmonics of 60 hz. Plug-in
> UPSes output their dirtiest power when in battery backup mode
> with sine waves at 180 hz, 300 hz, 420 hz, etc - which may
> cause increased and destructive heating inside a transformer.

Certainly possible and mostly correct, though for modern televisions which
all use SMPS, it is hardly a factor. More likely a problem for conventional
PS in audio equipment.


> When does the plug-in UPS output cleanest power? When power
> relay connects appliance directly to AC mains. Will a UPS
> protect a TV from power cycling damage? No. We have
> provided the numbers. A UPS might eliminate maybe three power
> offs. A big NO because numbers make it that obvious.

Like I said previously, as have others, it is not a big issue and having a
UPS likely won't matter much. So your entire post comes down to a couple of
bits of useful info that have already been stated...deflate your ego now.

> Even worse, the UPS in battery backup mode could adversely
> affect that TV (depending on the TV design). Does TV get
> standby power through a line transformer? If yes, then the
> plug-in UPS could promote a TV failure.

Hardly. The degree of heating caused by sloppy a.c. generation in a UPS is
unlikely to be a matter of concern. This is particularly true if power
outages rarely occur, as you argue above. Also, most sets now use standby
circuits that run off of the SMPS conversion, making the dirty power largely
irrelevant.

> Again, one must first learn the principles. Does that UPS
> output a modified sine wave? Yes. 'Dirty' electricity is
> chock full of sine waves. Not all those sine waves are TV
> friendly. Want a better answer? Lets see the schematics, the
> numbers, and other important details. First we need facts -
> not junk science speculations.

Understanding the principles and applying them without knowledge of the
application is a common error made by engineers, and others. You have
proved to be artful in doing so, to the point that your posts confuse and
mislead people enough to deserve a thorough rebuttal.

> Is power cycling destructive? Most often, only junk science
> says leave it on. Credibility. Did he provide numbers?
> Those who claim so much damage from power cycling constantly
> avoid numbers to promote the myth.

No one was arguing that one should leave a DLP projector on. No one was
disputing that hours of use is the main determinant of failure in DLP lamps.
What is clear is that all of the vendors consider start cycles to be a
factor in aging and avoiding them is sensible, up to a point. No one has
supplied numbers because manufacturers have not supplied them. It only
makes sense, if one experiences lots of power outages, to have some
protection from them. As we also stated, for most people, it doesn't make
much difference.

Leonard
!