On Wed, 15 Aug 2007 08:43:53 GMT, "Arfa Daily"
wrote:


I actually think that at the moment, digital display technology - without
wishing to open up *that* can of worms again - lags behind CRT display
technology, by a significant amount. Next time you go to the cinema, look up
at the booth window and see if you can see film looping around the ceiling.
If you can't, then it uses one of those new-fangled DLP video projectors.
Sit back comfortably with your popcorn, and wonder what's happened to your
eyes, when the first car drives across the screen ... d;~}


Many people in their daily use cannot see any lag or
ghosting from 19" and smaller LCD computer monitors.

If you can't actually see it, does it matter if it exists?
I can play 50 FPS video or games running at over 50 FPS on a
19" LCD computer monitor and not see any problems except the
obvious lack of contrast (but with CRT I am spoiled in this
respect, having bought Diamondtron tube based monitors for
the last few I used myself before switching to primarily LCD
usage).

"John Williamson" wrote in message
...
Arfa Daily wrote:
"CBFalconer" wrote in message
...
Arfa Daily wrote:
"CBFalconer" wrote in message
Arfa Daily wrote:
... snip ...
OK. I'm not sure that 'RMS' is the right term to attach to any
value derived from a ragged-arsed waveform, as it is a mathematical
function normally associated with symetrical waveforms, which the
draw by a SMPS may very well not be, but I see what you're saying.

What I am trying to say is that a chip which is designed to produce
an RMS reading from a sine wave, may well produce a meaningful
figure from a non-sinusoidal waveform also, but *only* if it is
still symetrical.
Oh? Try a square wave, for example. Nice and symetrical. You are
over-simplifying.
Explain ?
The integral is peak voltage times current. Simple. Not 0.7 *
peak voltage. Current is also constant for resistive loads, not
proportional to voltage. RMS doesn't work.


OK. Well in that case, I don't think that I was over-simplifying, because
if you have read the whole thread, you will see that it was I who
questioned the validity of attaching an RMS value to a non-sinusoidal
waveform. However, several posters then came back to me with considerable
levels of mathematical proof, to say that RMS was a valid notion for any
waveshape or symmetry factor, the only qualifiers being DC content or
variable cycle periodicity. Although it might not be too clear, that
second paragraph was more of a musing based on that. My original
contention was that a power meter (or whatever) designed to derive and
display an RMS value from a sine wave, would not give a meaningful
reading from non-sinusoidal or non-symmetrical drawing loads, such as a
SMPS may be, for instance. The replies suggested that the waveshape was
immaterial, and that the chipset could very easily still calculate a
meaningful result. I was a little sceptical about this, as it seemed to
fly in the face of what I was taught many years ago in college, but I
bowed to what seemed to be superior knowledge in the field.

Now, you seem to be saying something quite different ? Comments ?

Arfa


Sorry to butt in here, but when I was studying such things, the RMS value
of a current or voltage waveform was calculated by working out the area
inside the curve plotted over a full cycle, which then allowed you to
calculate an equivalent DC value. This involved counting squares on graph
paper of the plotted waveform or similarly counting squares on a
calibrated oscilloscope tube face. The earlier & most of the current cheap
meters that give an alleged RMS reading take a peak reading & apply a
correction factor of 0.707 to it (1 divided by the (near enough) square
root of 2), as that gives the right answer with a clean sine wave, which
is what most of these meters are used to measure. (Mains power round here
is near enough a pure sine wave that you can ignore the error, as it's
less than the accuracy of the meter)
The RMS value of a (theoretical) pure square wave is exactly the same as
the average of the absolute values of the positive & negative peaks, as
the value is either fully positive or fully negative, with, in theory, no
other value being present.

The most (theoretically) accurate way to measure RMS values is to use a
hot wire meter, which doesn't care what the waveform is, it just measures
the heating effect which is more or less frequency independent & includes
any DC offset automatically.


Tciao for Now!

John.

Yes, all agreed, but the shape of the mains waveform is immaterial, unless
you are talking a purely resistive load like a light bulb. The point that I
have been trying to make all along is that when you are trying to measure
power, it's a function of both voltage and current draw, and in the case of
a SMPS, especially one that's in standby mode, the current draw from the
mains supply voltage, is very likely to be anything *but* sinusoidal.

Arfa

"kony" wrote in message
...
On Wed, 15 Aug 2007 08:43:53 GMT, "Arfa Daily"
wrote:


I actually think that at the moment, digital display technology - without
wishing to open up *that* can of worms again - lags behind CRT display
technology, by a significant amount. Next time you go to the cinema, look
up
at the booth window and see if you can see film looping around the
ceiling.
If you can't, then it uses one of those new-fangled DLP video projectors.
Sit back comfortably with your popcorn, and wonder what's happened to your
eyes, when the first car drives across the screen ... d;~}


Many people in their daily use cannot see any lag or
ghosting from 19" and smaller LCD computer monitors.

If you can't actually see it, does it matter if it exists?

Well no, of course not. But I would be surprised if anyone actually couldn't
see it. I prefer to believe that it's a little bit of 'King's New Clothes'
syndrome, and people don't really *want* to see it, having just shelled out
a bunch of their hard-earned, on what they believed was going to be better
than they already had. Even my wife can see it, without any prodding from
me, and she's about as technical as a pound of oranges ...


I can play 50 FPS video or games running at over 50 FPS on a
19" LCD computer monitor and not see any problems except the
obvious lack of contrast (but with CRT I am spoiled in this
respect, having bought Diamondtron tube based monitors for
the last few I used myself before switching to primarily LCD
usage).

Yes, there is the lack of contrast issue, which is not insignificant in
itself. My son plays video games on his PC at high frame rates also. He also
has an expensive HP 4:3 LCD, and whilst it's pretty good at displaying fast
motion, there is, never-the-less, motion blur that wasn't there when he used
CRT monitors. When a pixel represents decimals of a uS, and the time to
switch that pixel is around a mS at best, there must be motion blur created.

Arfa

Arfa Daily wrote:
"John Williamson" wrote in message
...
Arfa Daily wrote:

Sorry to butt in here, but when I was studying such things, the RMS value
of a current or voltage waveform was calculated by working out the area
inside the curve plotted over a full cycle, which then allowed you to
calculate an equivalent DC value. This involved counting squares on graph
paper of the plotted waveform or similarly counting squares on a
calibrated oscilloscope tube face. The earlier & most of the current cheap
meters that give an alleged RMS reading take a peak reading & apply a
correction factor of 0.707 to it (1 divided by the (near enough) square
root of 2), as that gives the right answer with a clean sine wave, which
is what most of these meters are used to measure. (Mains power round here
is near enough a pure sine wave that you can ignore the error, as it's
less than the accuracy of the meter)
The RMS value of a (theoretical) pure square wave is exactly the same as
the average of the absolute values of the positive & negative peaks, as
the value is either fully positive or fully negative, with, in theory, no
other value being present.

The most (theoretically) accurate way to measure RMS values is to use a
hot wire meter, which doesn't care what the waveform is, it just measures
the heating effect which is more or less frequency independent & includes
any DC offset automatically.


Tciao for Now!

John.

Yes, all agreed, but the shape of the mains waveform is immaterial, unless
you are talking a purely resistive load like a light bulb. The point that I
have been trying to make all along is that when you are trying to measure
power, it's a function of both voltage and current draw, and in the case of
a SMPS, especially one that's in standby mode, the current draw from the
mains supply voltage, is very likely to be anything *but* sinusoidal.

Arfa


It's also likely not to be a simple product of the RMS current drawn &
the RMS voltage of the supply, as the input circuitry contains reactive
and regulatory elements that alter the phase relationships between the
current & the voltage in a manner that can't necessarily be predicted
easily.
Most of the ones I've looked at have a rectifier across the mains feed,
with inductive & capacitive elements in the circuit before the
rectifier, with a SMPS pulling power from the rectifier after a
smoothing filter. This gives a power factor that varies with load,
possibly cyclically even at steady load if the oscillator of the SMPS
isn't locked to the incoming mains frequency.
Then the invertor on the output just runs off the DC from the battery
pack/ SMPS combination.

As you say, though, the shape of the mains waveform is immaterial, apart
from harmonics altering the power factor by altering the relative
impedances of the inductors & capacitors.

Tciao for Now!

John.

"John Williamson" wrote in message
...

The most (theoretically) accurate way to measure RMS values is to use a
hot wire meter, which doesn't care what the waveform is, it just
measures the heating effect which is more or less frequency independent
& includes any DC offset automatically.

That's one way, subject to the problems with accurately measuring the
heating of a resistive element.

Another way to obtain a true RMS reading without complex electronics is to
use a certain kind of meter movement that mechanically integrates the
product of the current and the voltage. There are two sets of windings in
the meter, one for current and one for voltage. Their attraction or
repulsion that drives the pointer is based on the product of the current in
the windings. I have one that was made by RCA, and a very common tool during
the 50s, 60s, 70s, and 80s.

Yes, all agreed, but the shape of the mains waveform is immaterial,
unless you are talking a purely resistive load like a light bulb.

Simply not true. Even light bulbs have some degree of sensitivity to the
waveform, unless they have filaments with very long thermal time constants.

Historically rectifier-based power supplies have been very sensitive to wave
form shape, because their output voltage is strongly influenced by the peak
value of the power line wave.

In the old days some magnetic power line voltage regulators put out a fairly
pure square wave. This did a pretty fair job of heating tube filaments, but
did not provide full B+ voltage from the power supply. The problem was the
low peak voltage. If you jacked up the line voltage to get full B+, the tube
filaments ran hot and tube life suffered.

The point that I
have been trying to make all along is that when you are trying to measure
power, it's a function of both voltage and current draw, and in the case
of a SMPS, especially one that's in standby mode, the current draw from
the mains supply voltage, is very likely to be anything *but* sinusoidal.

Agreed. However there is a newer kid on the block, and that's the power
factor corrected SMPS. This technology has been reduced to an IC, and it
shows up in items as humble as compact flourescent light bulbs. If the
power factor is 1.00 or approaches it, then the current and voltage are
largely in-phase.

In article ,
"Arny Krueger" wrote:

"John Williamson" wrote in message
...

The most (theoretically) accurate way to measure RMS values is to use a
hot wire meter, which doesn't care what the waveform is, it just
measures the heating effect which is more or less frequency independent
& includes any DC offset automatically.

That's one way, subject to the problems with accurately measuring the
heating of a resistive element.

Another way to obtain a true RMS reading without complex electronics is to
use a certain kind of meter movement that mechanically integrates the
product of the current and the voltage. There are two sets of windings in
the meter, one for current and one for voltage. Their attraction or
repulsion that drives the pointer is based on the product of the current in
the windings. I have one that was made by RCA, and a very common tool during
the 50s, 60s, 70s, and 80s.

And a third practical way, which I suspect devices like the kill-a-watt
meter and "true RMS" digital multimeters use, is to sample the
voltage/current waveform and then use a microcontroller to perform the
appropriate integration. Microcontrollers are amazingly cheap and
powerful these days. As long as the waveforms you're measuring are
relatively slow (compared to the sampling frequency), it should be quite
accurate. For mains work, this isn't a hard thing to achieve--a few
kilohertz sampling rate is probably overkill.

--
Andrew Erickson

"He is no fool who gives what he cannot keep to gain that which he cannot
lose." -- Jim Elliot

Yes, all agreed, but the shape of the mains waveform is
immaterial, unless you are talking a purely resistive
load like a light bulb. The point that I have been trying
to make all along is that when you are trying to measure
power, it's a function of both voltage and current draw,
and in the case of a SMPS, especially one that's in
standby mode, the current draw from the mains supply
voltage, is very likely to be anything *but* sinusoidal.

Arfa
It's also likely not to be a simple product of the RMS
current drawn & the RMS voltage of the supply, as the
input circuitry contains reactive and regulatory elements
that alter the phase relationships between the current &
the voltage in a manner that can't necessarily be
predicted easily.
(snip)
Tciao for Now!

John.

This all started with a discussion of the Kill-A-Watt meter
which measures RMS voltage, RMS current, and Watts. Maybe
the following will clear some of the confusion.
The computation of RMS was described in an earlier post. The
product of RMS voltage and RMS current is Volt-Amps. Power,
and therefore power consumption (Watts=power/second), is
computed by the integration of the product of instantaneous
volts and amps over time. The power factor then becomes
Watts/Volt-Amps. The accuracy of the wattage and RMS
calculations with voltage or current waveforms that change
rapidly is related to the sampling rate used in the
integration. Any wave shape for either voltage or current
will produce mathematically meaningful RMS and power
measurements. I am sure someone will point out any mistakes
I have made here.

David

Arfa Daily wrote:
"kony" wrote in message

.... snip ...

I can play 50 FPS video or games running at over 50 FPS on a 19"
LCD computer monitor and not see any problems except the obvious
lack of contrast (but with CRT I am spoiled in this respect,
having bought Diamondtron tube based monitors for the last few I
used myself before switching to primarily LCD usage).

Yes, there is the lack of contrast issue, which is not
insignificant in itself. My son plays video games on his PC at high
frame rates also. He also has an expensive HP 4:3 LCD, and whilst
it's pretty good at displaying fast motion, there is,
never-the-less, motion blur that wasn't there when he used CRT
monitors. When a pixel represents decimals of a uS, and the time to
switch that pixel is around a mS at best, there must be motion blur
created.

I suspect that the real effect is caused by the pixel decay time.
CRTs operate with a refresh rate between 25 and about 100 hz,
depending on interlace, resolution, etc. This means a pixel will
be refreshed no sooner than 10 mS (up to about 40) from the earlier
energization. If, at that refresh time, the pixel has a
substantial carry-over from the previous level, there will be
blurring. If the carry-over is too small, there will be flickering
and other evil effects. I believe the LCDs have, effectively, zero
carry-over, and compensate by having an instantaneous reset of any
previously set level; i.e. they don't require interlace, refresh,
etc. except to show motion.

--
Chuck F (cbfalconer at maineline dot net)
Available for consulting/temporary embedded and systems.
http://cbfalconer.home.att.net



--
Posted via a free Usenet account from http://www.teranews.com

Power, and therefore power consumption
(watts=power/second)...

Power is energy/second. Power is not consumed, energy is consumed.

Agreed. However there is a newer kid on the block, and that's the power
factor corrected SMPS. This technology has been reduced to an IC, and it
shows up in items as humble as compact flourescent light bulbs. If the
power factor is 1.00 or approaches it, then the current and voltage are
largely in-phase.

I checked some excellent CFLs from Home Despot (instant turn-on, excellent
color balance) with the Kil-a-Watt. It showed a power factor around 65%,
which struck me as rather low. Such a low PF also partly offsets the
money-saving advantages of fluorescent lamps.

Opinions, anyone?

David wrote:

.... snip ...

This all started with a discussion of the Kill-A-Watt meter which
measures RMS voltage, RMS current, and Watts. Maybe the following
will clear some of the confusion.
The computation of RMS was described in an earlier post. The
product of RMS voltage and RMS current is Volt-Amps. Power, and
therefore power consumption (Watts=power/second), is computed by
the integration of the product of instantaneous volts and amps
over time. The power factor then becomes Watts/Volt-Amps. The
accuracy of the wattage and RMS calculations with voltage or
current waveforms that change rapidly is related to the sampling
rate used in the integration. Any wave shape for either voltage
or current will produce mathematically meaningful RMS and power
measurements. I am sure someone will point out any mistakes I have
made here.

You omitted that a periodicity is required. An infinite wavelength
is also allowable. :-)

BTW, please do not remove attributions for material you quote.

--
Chuck F (cbfalconer at maineline dot net)
Available for consulting/temporary embedded and systems.
http://cbfalconer.home.att.net



--
Posted via a free Usenet account from http://www.teranews.com

William Sommerwerck wrote:
Agreed. However there is a newer kid on the block, and that's the power
factor corrected SMPS. This technology has been reduced to an IC, and it
shows up in items as humble as compact flourescent light bulbs. If the
power factor is 1.00 or approaches it, then the current and voltage are
largely in-phase.

I checked some excellent CFLs from Home Despot (instant turn-on, excellent
color balance) with the Kil-a-Watt. It showed a power factor around 65%,
which struck me as rather low. Such a low PF also partly offsets the
money-saving advantages of fluorescent lamps.

Opinions, anyone?

Well, your computer switcher probably has a power factor of about 1.2 to
1.5... so run a couple computers and the lead and lag will cancel one
another out...
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

"William Sommerwerck" wrote in message
. ..

Agreed. However there is a newer kid on the block, and that's the power
factor corrected SMPS. This technology has been reduced to an IC, and it
shows up in items as humble as compact flourescent light bulbs. If the
power factor is 1.00 or approaches it, then the current and voltage are
largely in-phase.

I checked some excellent CFLs from Home Despot (instant turn-on, excellent
color balance) with the Kil-a-Watt. It showed a power factor around 65%,
which struck me as rather low. Such a low PF also partly offsets the
money-saving advantages of fluorescent lamps.

Opinions, anyone?

The dimmable CFLs I get from eBay (love those California lawmakers!) have PF
speced 0.90. I haven't got around to testing one, though.

On 8/14/2007, CBFalconer posted this:
Arfa Daily wrote:
"CBFalconer" wrote in message
Arfa Daily wrote:

... snip ...

OK. I'm not sure that 'RMS' is the right term to attach to any
value derived from a ragged-arsed waveform, as it is a mathematical
function normally associated with symetrical waveforms, which the
draw by a SMPS may very well not be, but I see what you're saying.

What I am trying to say is that a chip which is designed to produce
an RMS reading from a sine wave, may well produce a meaningful
figure from a non-sinusoidal waveform also, but *only* if it is
still symetrical.

Oh? Try a square wave, for example. Nice and symetrical. You are
over-simplifying.

Explain ?

The integral is peak voltage times current. Simple. Not 0.7 *
peak voltage.

No, the integral is instantaneous voltage squared. Simple.

Current is also constant for resistive loads, not
proportional to voltage. RMS doesn't work.

You are contradicting Ohm's law, e = ir, which can be rearranged to
read i = e/r. Current is precisely proportional to voltage for
resistive loads. Simple.

I've used small letters to follow an old convention (is it still used?)
that lower-case letters represent varying values and upper-case letters
represent constant values (such as in analyzing DC circuits).

--
Chuck F (cbfalconer at maineline dot net)
Available for consulting/temporary embedded and systems.
http://cbfalconer.home.att.net

--
Gene E. Bloch (Gino)
letters617blochg3251
(replace the numbers by "at" and "dotcom")

On 8/15/2007, William Sommerwerck posted this:
Agreed. However there is a newer kid on the block, and that's the power
factor corrected SMPS. This technology has been reduced to an IC, and it
shows up in items as humble as compact flourescent light bulbs. If the
power factor is 1.00 or approaches it, then the current and voltage are
largely in-phase.

I checked some excellent CFLs from Home Despot (instant turn-on, excellent
color balance) with the Kil-a-Watt. It showed a power factor around 65%,
which struck me as rather low. Such a low PF also partly offsets the
money-saving advantages of fluorescent lamps.

Opinions, anyone?

Great minds: I also call it Home Despot...

--
Gene E. Bloch (Gino)
letters617blochg3251
(replace the numbers by "at" and "dotcom")

The dimmable CFLs I get from eBay (love those California lawmakers!)
have PF speced 0.90. I haven't got around to testing one, though.

What brand?

I bought a dimmable GE two years ago, and it worked. You get only about 10
steps, at the top of the X-10's 256-step range, but it works.

"William Sommerwerck" wrote in message
. ..

The dimmable CFLs I get from eBay (love those California lawmakers!)
have PF speced 0.90. I haven't got around to testing one, though.

What brand?

ULA, made you-know-where.

My understanding is that these bulbs are being sold in California for about
$1.00 each in Wal-Marts, with subsidy from the local power company.

I bought a dimmable GE two years ago, and it worked. You get only about 10
steps, at the top of the X-10's 256-step range, but it works.

The dimmable CFs I've been using have a standard Edison base and fit in
standard light bulb sockets. They are infinitely variable over a range that
goes down to pretty dark and then nothing, to full bright.

I use a few of them around the house, driven by standard wall-plate
residential dimmers.

I'm using 48 of them in 6 chandeliers driven by standard DMX-controlled
quad dimmer packs at church. Their brightness/drive curve is nonlinear, but
useable.

As you say, the color temperature is very constant over a usable range of
intensities compared to incadescent PAR bulbs. While they start pretty much
on the dime, they do get about 50% brighter the first minute or two of
operation.

If you've got the fixtures and ballasts that are designed for them,
4-terminal dimmable flourescents are marvelous. They dim over about the same
range of brightness and as linearly as an incadescent, but with constant
color temperature.

I use a few of them around the house, driven by standard
wall-plate residential dimmers.

Rheostats? Triacs? I'm not familiar with the current technology. (X-10 is
triac-controlled, I believe.)


As you say, the color temperature is very constant over a
usable range of intensities compared to incadescent PAR bulbs.

Actually, I didn't say that, but you'd expect it to be so, given that a
fluorescent lamp is a quantum device.


While they start pretty much on the dime, they do get about
50% brighter the first minute or two of operation.

That's what I noted with the Home Despot lamps. It was startling at first to
see a fluorescent lamp come on faster than an incandescent.

In comp.sys.ibm.pc.hardware.misc William Sommerwerck wrote:
I use a few of them around the house, driven by standard
wall-plate residential dimmers.

Rheostats? Triacs? I'm not familiar with the current technology. (X-10 is
triac-controlled, I believe.)


As you say, the color temperature is very constant over a
usable range of intensities compared to incadescent PAR bulbs.

Actually, I didn't say that, but you'd expect it to be so, given that a
fluorescent lamp is a quantum device.

Very much so, but mostly in the same sense that a glowing
pice of metal is a quantum device....

Arno

On 8/15/2007, Arno Wagner posted this:
In comp.sys.ibm.pc.hardware.misc William Sommerwerck
wrote:
I use a few of them around the house, driven by standard
wall-plate residential dimmers.

Rheostats? Triacs? I'm not familiar with the current technology. (X-10 is
triac-controlled, I believe.)


As you say, the color temperature is very constant over a
usable range of intensities compared to incadescent PAR bulbs.

Actually, I didn't say that, but you'd expect it to be so, given that a
fluorescent lamp is a quantum device.

Very much so, but mostly in the same sense that a glowing
pice of metal is a quantum device....

Arno

No, not at all in the same *sense*, but to the same *degree*. The
fluorescents use electron transitions in Hg to generate a line
spectrum, and then a fluorescent coating inside the bulb to convert the
lines in question into new lines and bands. This is in no way
comparable to black-body radiation, which is a continuum. This, of
course, is an *opinion* :-)

However, both are still quantum-mechanical devices at bottom. In fact,
it has been said that it was trying to solve the BB radiation problem
that led Planck to the discovery of his constant: he took the limit of
something as some differential went to zero and it didn't work. But he
got the right answer when he set the differential to a finite value,
around 6.27E-27, IIRC.

Close (sort of): Google gives me "Planck's constant = 6.626068 × 10-34
m2 kg / s", so I left out the second 6 - but I am used to it in cgs,
rather than mks, so the exponent is correct. That *would* be more
believable if I had expressed the units, erg-sec, above :-)

--
Gene E. Bloch (Gino)
letters617blochg3251
(replace the numbers by "at" and "dotcom")

"Gene E. Bloch" wrote in message
...
On 8/15/2007, William Sommerwerck posted this:
Agreed. However there is a newer kid on the block, and that's the power
factor corrected SMPS. This technology has been reduced to an IC, and it
shows up in items as humble as compact flourescent light bulbs. If the
power factor is 1.00 or approaches it, then the current and voltage are
largely in-phase.

I checked some excellent CFLs from Home Despot (instant turn-on,
excellent
color balance) with the Kil-a-Watt. It showed a power factor around 65%,
which struck me as rather low. Such a low PF also partly offsets the
money-saving advantages of fluorescent lamps.

Opinions, anyone?


Virtually all CFLs are low power factor, HPF would add to the cost and
people wouldn't buy them.

In the US, domestic electric meters measure true power, so the power factor
doesn't make any difference in the bill, it does strain the distribution
system more though.

"kony" wrote in message
...
On Wed, 15 Aug 2007 08:43:53 GMT, "Arfa Daily"
wrote:


I actually think that at the moment, digital display technology - without
wishing to open up *that* can of worms again - lags behind CRT display
technology, by a significant amount. Next time you go to the cinema, look
up
at the booth window and see if you can see film looping around the
ceiling.
If you can't, then it uses one of those new-fangled DLP video projectors.
Sit back comfortably with your popcorn, and wonder what's happened to your
eyes, when the first car drives across the screen ... d;~}


Many people in their daily use cannot see any lag or
ghosting from 19" and smaller LCD computer monitors.

If you can't actually see it, does it matter if it exists?
I can play 50 FPS video or games running at over 50 FPS on a
19" LCD computer monitor and not see any problems except the
obvious lack of contrast (but with CRT I am spoiled in this
respect, having bought Diamondtron tube based monitors for
the last few I used myself before switching to primarily LCD
usage).


I sure can, maybe my eyes are just better than average, there's those
"golden ear" audiophools I always thought were nuts, but maybe some of them
aren't as nutty as I thought. I've got a high end 20" flat panel on my desk
at work, it looks really good, but still not as good as the 22" flat
Trinitron CRT I have at home. Geometry is flawless, but the picture doesn't
look as smooth and clean as the CRT, it looks more "digital".

On Thu, 16 Aug 2007 05:13:09 GMT, "James Sweet"
wrote:


If you can't actually see it, does it matter if it exists?
I can play 50 FPS video or games running at over 50 FPS on a
19" LCD computer monitor and not see any problems except the
obvious lack of contrast (but with CRT I am spoiled in this
respect, having bought Diamondtron tube based monitors for
the last few I used myself before switching to primarily LCD
usage).


I sure can, maybe my eyes are just better than average, there's those
"golden ear" audiophools I always thought were nuts, but maybe some of them
aren't as nutty as I thought. I've got a high end 20" flat panel on my desk
at work, it looks really good, but still not as good as the 22" flat
Trinitron CRT I have at home. Geometry is flawless, but the picture doesn't
look as smooth and clean as the CRT, it looks more "digital".


I did not write "some LCD", I wrote about current generation
19" and lower.

It doesn't matter if you see ghosting on 20"+, for the
purpose of the discusstion which is whether smaller
comparable resolutions exhibit it.

If we were taking about higher resolutions than native to
19", then CRTs lose on another front because their refresh
rate and pixel boundaries get so blurred it is no longer an
accurate output.

Looking more "digital" is not necessarily a flaw. A video
card does not transmit an infinitely high res, flawless
image, it transmits pixels. Accurately representing those
pixels is the monitor's job, not blurring them so they look
more lifelike.

"James Sweet" wrote in message
news:F1Rwi.3385$Be.1378@trndny04...

"kony" wrote in message
...
On Wed, 15 Aug 2007 08:43:53 GMT, "Arfa Daily"
wrote:


I actually think that at the moment, digital display technology - without
wishing to open up *that* can of worms again - lags behind CRT display
technology, by a significant amount. Next time you go to the cinema, look
up
at the booth window and see if you can see film looping around the
ceiling.
If you can't, then it uses one of those new-fangled DLP video projectors.
Sit back comfortably with your popcorn, and wonder what's happened to
your
eyes, when the first car drives across the screen ... d;~}


Many people in their daily use cannot see any lag or
ghosting from 19" and smaller LCD computer monitors.

If you can't actually see it, does it matter if it exists?
I can play 50 FPS video or games running at over 50 FPS on a
19" LCD computer monitor and not see any problems except the
obvious lack of contrast (but with CRT I am spoiled in this
respect, having bought Diamondtron tube based monitors for
the last few I used myself before switching to primarily LCD
usage).


I sure can, maybe my eyes are just better than average, there's those
"golden ear" audiophools I always thought were nuts, but maybe some of
them aren't as nutty as I thought. I've got a high end 20" flat panel on
my desk at work, it looks really good, but still not as good as the 22"
flat Trinitron CRT I have at home. Geometry is flawless, but the picture
doesn't look as smooth and clean as the CRT, it looks more "digital".

Hi James, goes it well ? Yes, that about says it. Perhaps it is just the
level of discernment, and it *is* just us, but that doesn't explain how my
wife thinks that the pictures are 'fuzzy' when anything is moving on them,
but makes no such comment when watching our 34" CRT Tosh TV, or the cinema
when it's projected filmstock, rather than a DLP video projector. She has no
technical axe to grind, as it were, and is interested in the picture only
for its entertainment value. Since I have had this high-end HP widescreen
LCD on the computer, which she also uses, she has made little comment other
than it looks "nice", which is true on the typically stationary pictures
that are normally displayed on it. I have, however, heard her comment that
the pictures on my son's (equally high-end) HP LCD are "out of focus", and
that would be typically when he is playing a game. Being non-technical, "out
of focus" is the best description that she can come up with for 'motion
blur'

Arfa

"William Sommerwerck" wrote in message
...

I use a few of them around the house, driven by standard
wall-plate residential dimmers.

Rheostats? Triacs?

Something solid state and cheap. Probably triacs.

I'm not familiar with the current technology. (X-10 is
triac-controlled, I believe.)

Something like triacs, I'm sure.

BTW I've found that there is now a middle ground in lighting, now that DMX
hardware is so deadly cheap. I've paid as little as $39.95 (sale) for a quad
dimmer pack that can handle the full load that a residential lighting
circuit can handle. There's a lot to be said for low voltage copper control
wiring.

As you say, the color temperature is very constant over a
usable range of intensities compared to incadescent PAR bulbs.

Actually, I didn't say that, but you'd expect it to be so, given that a
fluorescent lamp is a quantum device.

Exactly.

While they start pretty much on the dime, they do get about
50% brighter the first minute or two of operation.

That's what I noted with the Home Despot lamps.

The extended warm-up can be a bit disconcerting. Some bulbs can start out
pretty dim. They are lit OK, but they are pretty dim.

It was startling at first to
see a fluorescent lamp come on faster than an incandescent.

Try a CFL on a really cold Michigan morning, say in an unheated garage. ;-(

While they start pretty much on the dime, they do get about
50% brighter the first minute or two of operation.

That's what I noted with the Home Despot lamps.

The extended warm-up can be a bit disconcerting. Some bulbs
can start out pretty dim. They are lit OK, but they are pretty dim.

My first CFLs were Philips, and they took "forever" to come to a reasonable
brightness, let alone full. But the Home Despot cheapies are quite bright
from the moment they're enerigized, and take only about a minute to real
full brilliance.


It was startling at first to see a fluorescent lamp come on faster
than an incandescent.

Try a CFL on a really cold Michigan morning, say in an unheated
garage. ;-(

If I don't find a job soon, I might very well be living in an unheated
garage, come Christmas.

On 13 Ago, 02:07, Doc wrote:
Recently I asked about suggestions regarding a UPS. I ended up
getting an 875 VA 525 Watt "Geek Squad" model from Best Buy - yeah,
yeah, everyone says Geek Squad stuff is overhyped junk, but at $69 on
sale, the price seemed right.

It seems to handle my 2 computers fine - a PIV 2.4 gig and a PIII 933
mhz sharing a monitor. With both machines and the monitor on, the
onboard readout shows them well below the unit's max capacity, drawing
about .250 - .260 kw (which I assume translates to 250 - 260 watts) ,
with an estimated run time of 9 minutes with both computers. More than
enough to get me through short hit outages with both machines running.

Interesting to note how much of a difference the monitor makes.
Without the monitor - a 17" MAG CRT, the draw for both computers
drops under 200 watts and the estimate run time for the 2 computers
goes from 9 mins to 15mins. Over 20 mins with just one computer
running but no monitor.

Since this thing has a built-in watt usage meter, any reason I
couldn't hook it up to say a refrigerator or TV to check how much
wattage they're using?

I've a 600VA unit and it will also run 2 PCs with their monitors.
When the battery went dead I connected a 92 Ah lead acid battery as a
replacement and has been fine since. I did not like the idea to test a
discharge to see how long it would run but for sure much longer than
the 7Ah original battery. The UPS keeps a float charge at around 13.5V
which is fine for this battery, but I may at some day apply an
equalizing charge for better maintenance. Running just one PC the
inverter transistors don't get too hot I think it could hold a long
time, I've the power guaranteed

"kony" wrote in message
...
On Thu, 16 Aug 2007 05:13:09 GMT, "James Sweet"
wrote:


If you can't actually see it, does it matter if it exists?
I can play 50 FPS video or games running at over 50 FPS on a
19" LCD computer monitor and not see any problems except the
obvious lack of contrast (but with CRT I am spoiled in this
respect, having bought Diamondtron tube based monitors for
the last few I used myself before switching to primarily LCD
usage).


I sure can, maybe my eyes are just better than average, there's those
"golden ear" audiophools I always thought were nuts, but maybe some of
them
aren't as nutty as I thought. I've got a high end 20" flat panel on my
desk
at work, it looks really good, but still not as good as the 22" flat
Trinitron CRT I have at home. Geometry is flawless, but the picture
doesn't
look as smooth and clean as the CRT, it looks more "digital".


I did not write "some LCD", I wrote about current generation
19" and lower.

It doesn't matter if you see ghosting on 20"+, for the
purpose of the discusstion which is whether smaller
comparable resolutions exhibit it.

If we were taking about higher resolutions than native to
19", then CRTs lose on another front because their refresh
rate and pixel boundaries get so blurred it is no longer an
accurate output.

Looking more "digital" is not necessarily a flaw. A video
card does not transmit an infinitely high res, flawless
image, it transmits pixels. Accurately representing those
pixels is the monitor's job, not blurring them so they look
more lifelike.


Only if it has DVI output, and you are making use of it. Many video cards
still in common use, output three analogue waveforms created by hi -speed
DACs with at least 16 bit inputs, via the VGA output socket, which the
monitor, CRT or LCD, displays via pixels made up either from phosphor
triads, or LC cells. As we live in an analogue world, I fail to see how you
can contend that something which looks "more digital" is not flawed. If the
display looks anything different from how the real world looks, then it is
an inaccurate representation, which by definition, makes it flawed. If the
CRT display does anything to make the picture look closer to reality, then
that must make it more accurate, and thus less flawed.

I'm not too sure why you feel that a CRT monitor's refresh rate has any
impact on the accuracy of the displayed rendition of the input data. High
refresh rates are a necessity to facilitate high resolutions. The response
times of the phosphors are plenty short enough for this to not represent a
problem. I do not understand what you mean by a CRT's pixel boundaries (?)
getting blurred, and how that fits in with refresh rate.

The last thing that you say is a very odd statement. If the CRT monitor does
anything to make the image more lifelike, how do you make that out to be a
bad thing? By logical deduction, if any display technology reproduces the
data being sent to it more accurately than any other, and this actually
looks less lifelike than reality, then the data being sent must be
inaccurate, and thus flawed ...

Arfa

On 8/15/2007, James Sweet posted this:
"Gene E. Bloch" wrote in message
...
On 8/15/2007, William Sommerwerck posted this:
Agreed. However there is a newer kid on the block, and that's the power
factor corrected SMPS. This technology has been reduced to an IC, and it
shows up in items as humble as compact flourescent light bulbs. If the
power factor is 1.00 or approaches it, then the current and voltage are
largely in-phase.

I checked some excellent CFLs from Home Despot (instant turn-on, excellent
color balance) with the Kil-a-Watt. It showed a power factor around 65%,
which struck me as rather low. Such a low PF also partly offsets the
money-saving advantages of fluorescent lamps.

Opinions, anyone?


Virtually all CFLs are low power factor, HPF would add to the cost and people
wouldn't buy them.

In the US, domestic electric meters measure true power, so the power factor
doesn't make any difference in the bill, it does strain the distribution
system more though.

I was a little startled - you answered my post, clipped my (admittedly
silly) remark, and went on to actually answer the previous post.

I've never made a mistake like that (you can be forgiven for not
believing that!).

--
Gene E. Bloch (Gino)
letters617blochg3251
(replace the numbers by "at" and "dotcom")

"kony" wrote in message
...
On Thu, 16 Aug 2007 05:13:09 GMT, "James Sweet"
wrote:


If you can't actually see it, does it matter if it exists?
I can play 50 FPS video or games running at over 50 FPS on a
19" LCD computer monitor and not see any problems except the
obvious lack of contrast (but with CRT I am spoiled in this
respect, having bought Diamondtron tube based monitors for
the last few I used myself before switching to primarily LCD
usage).


I sure can, maybe my eyes are just better than average, there's those
"golden ear" audiophools I always thought were nuts, but maybe some of
them
aren't as nutty as I thought. I've got a high end 20" flat panel on my
desk
at work, it looks really good, but still not as good as the 22" flat
Trinitron CRT I have at home. Geometry is flawless, but the picture
doesn't
look as smooth and clean as the CRT, it looks more "digital".


I did not write "some LCD", I wrote about current generation
19" and lower.

It doesn't matter if you see ghosting on 20"+, for the
purpose of the discusstion which is whether smaller
comparable resolutions exhibit it.

If we were taking about higher resolutions than native to
19", then CRTs lose on another front because their refresh
rate and pixel boundaries get so blurred it is no longer an
accurate output.

Looking more "digital" is not necessarily a flaw. A video
card does not transmit an infinitely high res, flawless
image, it transmits pixels. Accurately representing those
pixels is the monitor's job, not blurring them so they look
more lifelike.


Well the LCD I have at work runs 1600x1200 native, the same as I run my CRT
at. This whole discussion is really moot, the CRT looks better to *me* and
that's all that matters, I don't care what the specs say or what others
claim. *I* see/notice the disadvantages of LCD panels, they bother *me*, and
therefore *I* prefer a good CRT. If you prefer a flat panel, then get one,
but this is a personal preference.

I want the image to look lifelike, the CRT does a good job of that, what do
I care if that's not the "monitor's job"?

I was a little startled - you answered my post, clipped my (admittedly
silly) remark, and went on to actually answer the previous post.

I've never made a mistake like that (you can be forgiven for not believing
that!).


I clipped the bottom, answered the part I was interested in, then simply
forgot to clip the top as well. So what?

On Thu, 16 Aug 2007 06:27:51 -0700, "William Sommerwerck"
wrote:

While they start pretty much on the dime, they do get about
50% brighter the first minute or two of operation.

That's what I noted with the Home Despot lamps.

The extended warm-up can be a bit disconcerting. Some bulbs
can start out pretty dim. They are lit OK, but they are pretty dim.

My first CFLs were Philips, and they took "forever" to come to a reasonable
brightness, let alone full. But the Home Despot cheapies are quite bright
from the moment they're enerigized, and take only about a minute to real
full brilliance.


Depending on how long ago you tried those "first" CFLs, it
may be a inappropriate comparison. Even the generic
off-brands were poor at first and evolved over time.

On Thu, 16 Aug 2007 23:03:26 GMT, "Arfa Daily"
wrote:


Only if it has DVI output, and you are making use of it.

False, while DVI is certainly better the higher the
resolution, it is a separate factor.

Many video cards
still in common use, output three analogue waveforms created by hi -speed
DACs with at least 16 bit inputs, via the VGA output socket, which the
monitor, CRT or LCD, displays via pixels made up either from phosphor
triads, or LC cells. As we live in an analogue world, I fail to see how you
can contend that something which looks "more digital" is not flawed.

It's pretty easy to understand once you realize that the
picture the video card is attempted to display that was
generated by the OS, IS DIGITAL. Anyone knows that
conversion back and forth between digital and analog causes
loss (to whatever extent, which must be a large extent if
you deem the conversion to change the image enough that you
feel it's better somehow).

If the
display looks anything different from how the real world looks, then it is
an inaccurate representation,

WRONG. An accurate representation is to preserve as much of
the input information as possible, not burring it so that it
becomes in some way closer to smooth but simultaneously
losing information in the process, becoming less detailed.

If all you want is blurry, smear some bacon grease on your
screen!

Sorry but you are 100% wrong.

My first CFLs were Philips, and they took "forever" to come
to a reasonable brightness, let alone full. But the Home Despot
cheapies are quite bright from the moment they're enerigized,
and take only about a minute to real full brilliance.

Depending on how long ago you tried those "first" CFLs, it
may be a inappropriate comparison. Even the generic
off-brands were poor at first and evolved over time.

It wasn't intended as a comparison, but a contrast. (Ask any English
teacher.) And the Philips were indeed early CFLs.

"kony" wrote in message
...
On Thu, 16 Aug 2007 23:03:26 GMT, "Arfa Daily"
wrote:


Only if it has DVI output, and you are making use of it.

False, while DVI is certainly better the higher the
resolution, it is a separate factor.

Many video cards
still in common use, output three analogue waveforms created by hi -speed
DACs with at least 16 bit inputs, via the VGA output socket, which the
monitor, CRT or LCD, displays via pixels made up either from phosphor
triads, or LC cells. As we live in an analogue world, I fail to see how
you
can contend that something which looks "more digital" is not flawed.

It's pretty easy to understand once you realize that the
picture the video card is attempted to display that was
generated by the OS, IS DIGITAL. Anyone knows that
conversion back and forth between digital and analog causes
loss (to whatever extent, which must be a large extent if
you deem the conversion to change the image enough that you
feel it's better somehow).

If the
display looks anything different from how the real world looks, then it is
an inaccurate representation,

WRONG. An accurate representation is to preserve as much of
the input information as possible, not burring it so that it
becomes in some way closer to smooth but simultaneously
losing information in the process, becoming less detailed.

If all you want is blurry, smear some bacon grease on your
screen!

Sorry but you are 100% wrong.

Well I'm sorry too, but it is you who is wrong. You would be right if we
were talking a signal that was being converted back and forth between types
or standards, but in the case of a computer generated picture, we are not.
We are talking a digitally created image of something that needs to be an
analogue one for our eyes to see. Whether the conversion from digital to
analogue takes place at the video card, or at the face of the monitor, it is
still a necessity that it takes place. The ultimate goal is to make it look
as lifelike as possible. If you think that by making it look sharper or in
some way different (or in your opinion, better) than real life, then you
have a very odd understanding of what the word 'accuracy' means in this
context.

Bacon grease ?? What a silly thing to throw into a discussion.

And what does your declaration of "false" about DVI mean ? If you want to
talk card-outputted 'pixels' then you need to be talking digital, which is
what a DVI output is. Otherwise, it's analogue as close as doesn't matter,
from the VGA socket.

And there's no need to shout by capitalization. I am neither deaf nor stupid
.... d;~}

Arfa

Arfa Daily wrote:

And there's no need to shout by capitalization. I am neither deaf nor stupid
... d;~}


Just grouchy, some days? (Like the rest of us.) ;-)


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

On Fri, 17 Aug 2007 08:40:09 GMT, "Arfa Daily"
wrote:


Well I'm sorry too, but it is you who is wrong. You would be right if we
were talking a signal that was being converted back and forth between types
or standards, but in the case of a computer generated picture, we are not.
We are talking a digitally created image of something that needs to be an
analogue one for our eyes to see. Whether the conversion from digital to
analogue takes place at the video card, or at the face of the monitor, it is
still a necessity that it takes place. The ultimate goal is to make it look
as lifelike as possible. If you think that by making it look sharper or in
some way different (or in your opinion, better) than real life, then you
have a very odd understanding of what the word 'accuracy' means in this
context.

Bacon grease ?? What a silly thing to throw into a discussion.


It is your goal to blur the information, which is what the
grease would do.

Pixel data is output by a computer to a video card. Since
human vision has far higher granularity, it is not expected
to look like reality except to the depth of granularity
possible by that pixel data, resolution. If the pixel data
is not preserved but rather smoothed to reduce your
perception of the pixels, it is also removing "data" from
the image, it is less accurate than the output was intended
to be. Monitor manufacturers strive to accurately reproduce
the image, not make it asthetically pleasing.

The goal is accuracy, not "lifelike". Lifelike and accuracy
can coexist but it will come from higher resolution, not
degradation of the signal upon output as you propose.

On Fri, 17 Aug 2007 08:40:09 GMT, "Arfa Daily"
wrote:


And there's no need to shout by capitalization. I am neither deaf nor stupid


Capitalization is also used in text for emphasis, not just
shouting.

In article ,
kony wrote:


Capitalization is also used in text for emphasis, not just
shouting.

More commonly, on usenet, leading and trailing asterisks indicate what
would be italicized for emphasis.

"kony" wrote in message
...
On Fri, 17 Aug 2007 08:40:09 GMT, "Arfa Daily"
wrote:


Well I'm sorry too, but it is you who is wrong. You would be right if we
were talking a signal that was being converted back and forth between
types
or standards, but in the case of a computer generated picture, we are not.
We are talking a digitally created image of something that needs to be an
analogue one for our eyes to see. Whether the conversion from digital to
analogue takes place at the video card, or at the face of the monitor, it
is
still a necessity that it takes place. The ultimate goal is to make it
look
as lifelike as possible. If you think that by making it look sharper or in
some way different (or in your opinion, better) than real life, then you
have a very odd understanding of what the word 'accuracy' means in this
context.

Bacon grease ?? What a silly thing to throw into a discussion.


It is your goal to blur the information, which is what the
grease would do.

Pixel data is output by a computer to a video card. Since
human vision has far higher granularity, it is not expected
to look like reality except to the depth of granularity
possible by that pixel data, resolution. If the pixel data
is not preserved but rather smoothed to reduce your
perception of the pixels, it is also removing "data" from
the image, it is less accurate than the output was intended
to be. Monitor manufacturers strive to accurately reproduce
the image, not make it asthetically pleasing.

The goal is accuracy, not "lifelike". Lifelike and accuracy
can coexist but it will come from higher resolution, not
degradation of the signal upon output as you propose.

Yeah,OK. I give in. You are right. I couldn't be more wrong if I tried. 35
years down the pan. Just as an experiment, I wiped goose grease all over my
LCD monitor and guess what? YOU ARE RIGHT !!!! ( that's for excited
emphasis, I'm not shouting at you ). My picture is now so blurred that it
looks just like the real world when I don't have my specs on. Accuracy or
what ?!!! Have you thought of marketing this idea ? You could put it in tubs
and sell it on the net as "Kony's patent image enhancing compound (blended
with REAL snake oil )"

My next plan is to see if I can drop a couple of bits on the input to the
video card's DAC. That should increase the 'granularity' no end. This is
another idea that could be put forward to monitor manufacturers to help them
in their goal of making the reproduced image anything but lifelike, and
better yet - *less* aesthetically pleasing !!

Boy, you're a lad ! All these wickedly good ideas ! If you don't market them
yourself, *I'm* gonna, and get really rich. Then you'll be sorry ! ;-)

Arfa