Switching ON an ATX power supply (when it's not connected to mobo) ?

Discussion in 'Gigabyte' started by Huang, Apr 18, 2004.

  1. Huang

    SmAfDiBoY Guest

    Yeah yeah but who has the biggest penis........

    that is truly all that matters.....
    SmAfDiBoY, Apr 21, 2004
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  2. The answer is "he does"
    here_and_there, Apr 21, 2004
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  3. Huang

    Boardpipe Guest

    .... matters to whom?
    Boardpipe, Apr 21, 2004
  4. Huang

    Ben Pope Guest

    You get a star for the correct usage of "whom".

    Ben Pope, Apr 21, 2004
  5. Oh pals, as English is not my first language, I won't mind
    too much to be blamed on poor spelling! In order to learn
    something, so, I go to "dictionary.yahoo.com" and search for
    "analog" and "analogue". I'm sure Yahoo's dictionary is
    nothing as prestige as Oxford's, Longman's or Webster's, but
    anyway, "analog" and "analogue" are two forms of the same

    Well, I did make a big mistake in my article, and it's more
    technical. It's about the resistance of an analog
    voltmeter. I'd digged out my old and reliable Sanwa
    YX-360TR multimeter (an analog one), and the DC50V range has
    a resistance of 20kohm. But common digital multimeter (like
    a Sanwa PM10) has DCV resistance of megaohms. So, I was
    wrong, as long as the voltmeter has a much higher resistance
    compare with the internal resistance of the power source,
    the voltmeter can be used. In modern days PC power supply,
    the internal resistance should be very low, say, < 1 ohm, a
    20kohm (analog) voltmeter is good enough to measure the
    potential difference. Okay, enough technical stuff, go back
    to party!

    Stephen Wong @ Hong Kong
    Stephen SM WONG, Apr 22, 2004
  6. Huang

    Boardpipe Guest

    Boardpipe, Apr 22, 2004
  7. Huang

    VWWall Guest

    It's long been said that the United States and the United Kingdom
    are separated by a common language. You're doing fine with both.
    One small correction. I'd be willing to bet that your analog
    meter has a resistance of 20kohm per volt. This means that it uses
    a 50 microamp meter movement. It would take 1 megohm in series for
    this to read full scale on 50 V, hence its input resistance would
    be ~1 megohm when used on the 50 V scale. This is 20kohm per volt.
    My digital meter has a resistance of 10 megohms on any DC scale.

    Your conclusion that either is OK to use to measure PSU voltages
    is correct.

    Virg Wall
    VWWall, Apr 22, 2004
  8. Huang

    Paul Guest

    That brings back memories for me. When I was a kid, I couldn't
    afford a real multimeter, and instead I bought a surplus
    bare meter movement (just the part with the analog needle on

    The meter movement is actually a current measuring device,
    and the smaller the current needed to drive it to full scale,
    the more sensitive it is. Before there were "buffered"
    analog or "buffered" digital meters, all you had in a meter
    was a resistor to set the scale and the meter movement.
    This is what I used as my voltmeter...
    + / \ -
    <-------- R = V_fullscale ---------| |------>
    ----------- \___/

    So, some example values. If the meter movement needed 50
    microamps to cause the needle to go to its max reading,
    this is termed a sensitivity of 20Kohms/volt. To make a
    meter that reads 1V full scale, you would stick R=20K
    as the series resistor. If you wanted the meter instead
    to be a 50V full scale meter, then R=1Megohm would be the
    choice to make. A handful of precision resistors and
    you are all set.

    The point of this story, is to point out that the load
    from that kind of meter actually changes depending on
    what scale the meter is set to. My meter was terrible
    for measuring small voltages.

    With analog and digital meters today, they have a
    buffer stage on the input, so the characteristics
    aren't quite the same. Much less current is needed on
    the input, to make the voltmeter work, and you don't have
    to worry about the loading like you used to with the
    simple minded design above. But my meter didn't need
    any batteries to make it work.

    Paul, Apr 22, 2004
  9. Oh, that proves my technical knowledge is as poor as my
    English spelling! Thank you for point out my mistakes!

    Well, I'm glad to participate in these newsgroups, you guys
    ensure me that there still exist some people who knows
    electronics (and circuit theory). One of my teachers in
    college tried to convince me to stop playing with
    electronics (analog and digital) but concentrate on
    programming. That happened some ten years ago. Most
    youngsters today don't make small projects, be it an audio
    amplifier, or a digital quiz machine. That's what I did
    when I was young.

    Try to do some tricks in analog world gives me as much fun
    as to write a decent program / algorithm. Much better than
    what I have to do in ERP/HRMS/Web to earn a living now.
    Those stupid programs made me remember grandma Grace Hopper!

    Okay, enough OT, back to Asus/Gigabyte/MSI reality now. I
    wonder how come an one cm square CPU die can consume 100W
    power, that means tens of ampere (if voltage is 1.5V +/-
    0.2V). That must be crazy. My good old days' 2N3055/MJ2955
    cannot take so much power, but enough to make me deaf
    through a pair of speakers. And my school teachers told me
    that up to a few hunder megahertz, there's no need to use a
    conductor, just a pair of close enough wires will let
    signals jump across. Well, how come the microwave range GHz
    running processor can still work accurately, but not act
    like a mesh antenna? And IBM is so proud of her Copper
    Interconnect. Wouldn't it be better to be called Air

    Stephen Wong @ Hong Kong
    Stephen SM WONG, Apr 22, 2004
  10. Huang

    Steve Sweet Guest

    Hi Stephen
    You'll find that's 20K Ohm per Volt which would give a total resistance of
    1,000,000 (1 MegOhm)
    Steve Sweet, Apr 22, 2004
  11. Huang


    Jun 27, 2006
    Likes Received:
    Need Help!!

    Dear All,
    I have power supply with AUX connectors, how can i connect this PUs without motherboard.
    amgadwadea, Jun 27, 2006
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