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Observations on a UPS - follow up to a previous post

Discussion in 'Electronic Repair' started by Doc, Aug 13, 2007.

  1. 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 :)
     
  2. James Sweet

    James Sweet Guest

    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.
     
  3. James Sweet

    James Sweet Guest


    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".
     
  4. kony

    kony Guest

    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.
     
  5. Arfa Daily

    Arfa Daily Guest

    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
     
  6. Arny Krueger

    Arny Krueger Guest

    Something solid state and cheap. Probably triacs.
    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.
    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.
    Try a CFL on a really cold Michigan morning, say in an unheated garage. ;-(
     
  7. While they start pretty much on the dime, they do get about
    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.

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

    Jeroni Paul Guest

    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 :)
     
  9. Arfa Daily

    Arfa Daily Guest

    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
     
  10. 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!).
     
  11. James Sweet

    James Sweet Guest

    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"?
     
  12. James Sweet

    James Sweet Guest

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

    kony Guest


    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.
     
  14. kony

    kony Guest

    False, while DVI is certainly better the higher the
    resolution, it is a separate factor.
    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).
    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.
     
  15. My first CFLs were Philips, and they took "forever" to come
    It wasn't intended as a comparison, but a contrast. (Ask any English
    teacher.) And the Philips were indeed early CFLs.
     
  16. Arfa Daily

    Arfa Daily Guest

    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
     

  17. 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
     
  18. kony

    kony Guest


    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.
     
  19. kony

    kony Guest


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

    Smitty Two Guest

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