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Are PC surge protectors needed in the UK?

Discussion in 'Electronic Repair' started by Lem, Jul 8, 2004.

  1. Ron Reaugh

    Ron Reaugh Guest

    Your wacko claims have already been refuted by my citation earlier in this
    thread.
    APC does include "common mode" as I cited.
     
  2. I suggest you consult the thread with the same title crossposted to the
    following groups before wasting any more time on w_tom:

    uk.comp.vendors,uk.comp.homebuilt,alt.comp.hardware,alt.comp.hardware.pc
    -homebuilt
     
  3. No Spam

    No Spam Guest

    Or RieserFS. But that is used by OS's other than Gate$
    Lemingware! :)
     
  4. In sci.physics, John Gilmer
    <>
    wrote
    NTFS stands for NT File System, presumably. (I've no idea what NT
    stands for. Certain jokesters have their own opinions, mine among
    them.)

    A file system is a method by which the unorganized data in
    a disk partition -- basically, a very long chain of blocks,
    or perhaps a mapping from an integer (the logical block
    address) to a fixed-size chunk of data (the block) -- can
    be organized into something more appetizing to humans:
    files, directories, symbolic links, or in Microsoft
    parlance (perhaps), documents, folders, and shortcuts.
    DOS 1.0's FAT filesystem didn't even have directories
    (that was added in 1.1 or 2.0; I forget which). NTFS is
    fairly sophisticated; it has, among other things:

    - per-file locking (to the intense annoyance of UNIX and Linux
    programmers, this appears to be on by default)
    - resource streams a la Macintosh (which aren't apparently used yet?)
    - Access Control Lists
    - Unicode support
    - Case-preserving filenames
    - a master file table, which is where the small files live
    - sparse files (files with "holes" in their blocklists -- a
    useful capability in some contexts related to databases, AIUI)
    - short file name capability for DOS backwards compatibility
    - hidden files
    - support for running a defragmenter while the volume is mounted.
    (Don't ask.)

    There are a few other capabilities but I'd have to look.

    If you really do want to look it up, you can try
    the Linux source code -- an NTFS implementation
    is in the kernel under /usr/src/linux/fs/ntfs or
    /usr/src/linux/Documentation/filesystems/ntfs.txt. It is
    definitely not for the faint of heart. There should
    be some documentation somewhere on Microsoft's website,
    of course; again, I'd have to look.

    HTH
     
  5. JM

    JM Guest

    quoting:

    The files aren't actually gone forever. If the power fails during the
    writing of the file, but the FAT have not been updated yet, the data will be
    found as "lost clusters" by Scandisk. It'll probably be in a bunch of
    pieces though, due to fragmentation.

    There are little backup programs that back up the disk's FAT's, boot sector,
    etc. in the event that that any of the disk's reserved sectors get
    obliterated by some other means.
     
  6. John Gilmer

    John Gilmer Guest

    Yeah, yeah.

    And NT stands for New Technology. It was written as a "Windows Like"
    operating system to run on hardware stuff by Sun Micro and the old DEC which
    used UNIX. At some point Micro$oft is to make the NT and Windows
    essentially the same operating system.

    Well, you lost me again. The directory is supposed to point to the entry
    in the FAT corresponding to the first "allocation unit" of the file. From
    my old memoery, the Intel development system just had a fixed directory.
    Directory entry #1 was the first allocation unit, etc. Longer files were
    accomodated by "chaining" directories.

    Well, WTF does it "lock?'
    That doesn't help.
    Which means ...
    Old stuff.
    Well, I understand was the defragmenter does in a FAT system but since I
    still don't understand how files are stored I can't understand how that are
    either fragmented or defragmented.
    Sorry, you have just asked me to think and work harder than I care to.
     
  7. Guest

    <snip>

    Yes, it IS in that citation, exactly where he said it is.
    It is the line below the two you quoted from the page
    he cited.

    It says: "Surge response time: 0 ns (instantaneous)
    normal mode, < 5ns common mode."
     
  8. Guest

    Consider a file system that writes empty blocks in numerical sequential
    order. Now think of a file that's deleted. This leaves an empty
    "hole" in the filled blocks. Now make a file whose size is less
    than the "hole". Now you have a smaller hole that will be filled
    with the next file that is written. That file is larger than the
    hole so the hole gets filled, then the next block that isn't filled
    is found and written into. Over time, all files, when viewed from
    the geometry of the physical disk look like swiss cheese.

    A defragmenter takes the whole file system and rewrites each file
    such that all its block numbers are monotonically increasing.

    Now, where this gets really, really fucked up is when the defragger
    program "forgets" which should be the next block (real easy to do
    with off-by-one bugs) or has to call its error handling when it
    can't do a fit or the block chain pointers become broken. The
    last one is a feature of all Misoft OSes because of memory
    management problems--but that's another nightmare in the not-an-OS
    biz.


    <snip>

    /BAH

    Subtract a hundred and four for e-mail.
     
  9. A. Cross posting. Second only to people who bitch about top posters .

    Leonard
     
  10. In sci.physics,
    <>
    wrote
    Indeed. In Linux, there's no defragger [*], because the file
    code in Linux is a little smarter. I'd admittedly have
    to look for the details though, and ext2's organization
    is quite different from FAT's or NTFS. FAT in particular
    is terrible, basically every file is a single chain --
    but you probably knew that already. NTFS is more or less
    as I've described it in my prior post, at a high level,
    and it feels like an engineered solution, whereas Linux's
    ext2 is more elegant, even if it's still engineered.
    But there's no perfect solution anyway; as you've described
    the problem, there's always going to be a hole or two,
    and a determined program can probably fragment any file
    system if it does something like the following:

    open big file
    write block to big file
    open little file
    write block to little file
    close it
    write block to big file
    open little file
    write block to little file
    close it
    write block to big file
    ....

    (It's a good thing the trend is towards centralized dedicated-machine
    syslog-type logging. :) )

    I'll admit to wondering whether NT had the rather interesting
    capability or not of "let's just write it here". I base
    this hypothesis on observations using DiskKeeper Lite, which
    copy I had at the time on a machine at my then-employer.
    Basically, the notion is to simply write the new block at
    an open sector in the cylinder over which the head is
    flying.

    Of course this would fragment things terribly, and I have no proof.
    But things did fragment pretty badly when I used such tools
    as Visual C++.
    [*] actually, there is, but it's very rarely used.
     
  11. w_tom

    w_tom Guest

    Common mode to what? To the safety ground? How much? Does
    it conduct 1 microamp in 5 ns to the safety ground? What kind
    of protection is that? Based upon facts and numbers provided,
    then my digital multimeter is even a better surge protector -
    a claim I can make because specs are better called an
    'executive summary'.

    At least that manufacturer once provided insufficient specs
    for Normal mode protection that the manufacturer does claim to
    provide:
    Now manufacturer cannot bother to provide even that
    insufficient information. After all, they are not trying to
    sell a 'common mode' claim to the informed. They dumb down
    the numbers into rubbish so that one who wishes MOVs absorb
    the energy of a surge will see what he wants.

    My car tires have a common mode response time AND that
    proves those tires are effective protection? Common mode
    what? Does not matter. That tiny phrse would be enough even
    for a poet to believe what he wants to know.

    How much common mode current in less than 5 ns? From what
    or which one wire is that common mode response? Is that
    common mode response really just a response inside the UPS
    controller circuit? Or is that a common mode response on the
    serial port. RS-232 is a common mode communication ports. So
    does the serial port haves a less than 5 ns response? Wow.
    That means the UPS must provide massive lightning protection -
    if living in the world of Harry Potter.

    IOW they mention 'common mode response' but give not one
    indication that the UPS provides common mode surge
    protection. It only does something - and they don't even say
    what or how much. That woefully insufficient and deceptive
    information is enough for some to loudly declare that a UPS
    provides lightning protection. IOW another urban myth has
    been promoted.

    There are no claims of common mode transient protection on
    the incoming AC input. Provided are words without relevance so
    that a poet might hope for common mode response to something -
    which therefore must be a direct lightning strike? It's
    called wild speculation on your part - the same person who
    foolishly believes shunt mode devices (such as wire) are
    designed to absorb energy. But an engineer says, "What is
    this crap. There is no numerical information to work with."

    That UPS does not claim common mode protection. It simply
    claims some undefined of response to common mode noise from or
    to an undefined location. It does not even say those 160
    joules are involved in such protection. Furthermore it admits
    to being grossly undersized - only 160 joules. A poet then
    can assume the response time means the UPS will conduct 50,000
    amps? A poet can. So can Harry Potter. Those who must deal
    in reality cannot.

    There is nothing in those specs beyond gobbledygook. Using
    ehsjr and Ron Reaugh reasoning, should we assume the UPS is
    sufficient even for aeronautical environments? After all,
    they do
    claim 'something' that myth purveyors can distort into a real
    world miracle.

    ehsjr - when will you claim that a faraday cage also makes
    that UPS so effective?

    I have this 741 op amp (a semiconductor amplifier). It also
    has a common mode rating. So that operational amplifier (that
    little IC) is also a lightning protector? Yes according to
    how ehsjr reasons. Give me a break. That UPS does not even
    claim to provide common mode protection - which is why they
    must all but encrypt their specifications. Its called name
    dropping. They dropped the phrase "common mode". That
    without any numbers is enough for ehsjr to loudly claim the
    UPS provides common mode protection. It is called Junk
    Science reasoning.
     
  12. Ron Reaugh

    Ron Reaugh Guest

    Nice try liar.
     
  13. w_tom

    w_tom Guest

    Power supply damages motherboard when a computer assembler
    purchases power supplies without consulting specifications.
    Intel specs for ATX power supplies demand that PSU not damage
    motherboard and other components:
    Too many computer assemblers don't have necessary technical
    knowledge and therefore don't even know that overvoltage
    protection (OVP) has been a defacto standard for 30+ years.
    That motherboard damage probably may be traceable to the
    ill-informed computer assembler (who does not demand specs) or
    a power supply manufacturer who outrightly lies on his
    specifications.

    There is nothing in a UPS that will accomplish the necessary
    OVP.

    Other essential functions that should be found in the power
    supply specification, but that many 'bean-counter' selected
    supplies may be missing:
    Specification compliance: ATX 2.03 & ATX12V v1.1
    Short circuit protection on all outputs
    Over voltage protection
    Over power protection
    EMI/RFI compliance: CE, CISPR22 & FCC part 15 class B
    Safety compliance: VDE, TUV, D, N, S, Fi, UL, C-UL & CB
    Hold up time, full load: 16ms. typical
    Efficiency; 100-120VAC and full range: >65%
    Dielectric withstand, input to frame/ground: 1800VAC, 1sec.
    Dielectric withstand, input to output: 1800VAC, 1sec.
    Ripple/noise: 1%
    MTBF, full load @ 25°C amb.: >100k hrs

    Power supplies missing these and other functions are sold at
    good profit in the North American computer clone market. OVP
    must be in all computer supplies but is often missing in clone
    computers.
     

  14. You need to specify which kind of UPS. Some UPS will provide excellant over
    voltage protection.

    Charles Perry P.E.
     
  15. w_tom

    w_tom Guest

    Overvoltage protection being discussed is on the 3.3, 5, and
    12 volt outputs. Table 11 from Intel specs even defines where
    and what that OVP must do. There is nothing in a plug-in UPS
    - outputting 120 VAC or 230 VAC to power supply - that is
    going to over voltage protect those DC outputs. Nothing.
    Only OVP that a UPS can provide - limit 120 VAC or 230 VAC.
    That will not solve an overvoltage problem on DC output of a
    'defective by design' power supply.

    J.J. asked:
    Yes, if power supply does not have OVP. No if supply does
    have the required OVP. No UPS will solve this missing OVP
    problem on DC outputs of power supply.
     
  16. w_tom

    w_tom Guest

    He has no knowledge, education or experience. He has not
    one technical fact to post in response. At least a junk
    scientist would try to invent a fact. Ron Reaugh is even
    worse than a junk scientist. He insults. Some claim that a
    plug-in UPS provided hardware protection. They can insult.
    That alone proves they must be right. Hey Ron. Is god on
    your side? No wonder you just 'know' these things.
     
  17. Keith

    Keith Guest

    Which would be?
    Certainly, at least to some point.
    You're *ONCE AGAIN* yalking through your ass.
    Really? I'm not from Missouri, but close enough. An IDE port monitors
    its supply voltage? You're simply talking out your ass, since it's been
    shot off repeatedly.

    You haven't a clue (as usual). NTFS is a slight modification to HPFS
    (written by the same SB, AFAIK) to make sure that OS/2 couldn't access NT
    systems. Neither is a JFS, nor is either less corrruptable than FAT.
    Indeed NT systems are far more susceptable to corruption than other
    similar OSs because of the agressive write buffering. Even (non-JFS) OS/2
    systems are better at self-healing than NT. Of course JFS is a standard
    part of OS/2 now. Windows? YMBK!
     
  18. Guest

    People might take you a tad more seriously if you exhibited
    a scintilla of trainability. The next line is a hint...

    <snip topposting>

    /BAH

    Subtract a hundred and four for e-mail.
     
  19. Guest

    How in the world does he think that FAT has anything to do with
    physical disk specs?
    That's really, really, really too bad. It used to know how.

    <snip>

    /BAH

    Subtract a hundred and four for e-mail.
     
  20. Guest

     
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