Are PC surge protectors needed in the UK?

Ron. Did you read your citation before posting it? Where is the reference to common mode protection? Where are any numbers that apply to common mode protection? Once APC used to provide far more numbers when they claimed to protect from Normal mode transients. Now they don't even make those claims. Numbers provided by Ron's citation:

Hell. They don't even list dBs for the noise filter. What kind of spec is that? Noise filter for what? Incoming AC line? Output power line? Clearly these are specs for the technically naive.

After one surge, the entire UPS is toast? Look at those pathetic numbers. Only 160 joules? Only 6500 amps? Effective protection starts at about 1000 joules and 50,000 amps. Thank you Ron for demonstrating pathetic protection from that plug-in UPS.

Oh - where do they mention anything about 'faraday cage' protection?

In the meantime, Ron describes normal mode protection:

Where is the comm>> Ok sir. Explain to us how a plug-in UPS provides common mode

Reply to
w_tom
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Gibber ignored.

And this wacko nonsense is from the guy who brought up DA design! At high frequency it is most ALL about topology!

Did you ever hear about the speed of light or about 1 foot per nanosecond?

Vaporizing...are you gonna bring in Klingons now as we seem to be having a bit to drink?

Reply to
Ron Reaugh

Right where I said it was as anyone who reads it can see for themselves. Gain some technical background before you tackle such technical issues.

Reply to
Ron Reaugh

If you'd read my previous post I already said exactly that.

No, inside a discontinuous Faraday cage....get a clue.

Reply to
Ron Reaugh

Put an impulse down a wire. Where on that wire will the impulse voltage first be seen? On the near end where the impulse starts? Obviously not. Impulse first appears at the far end of wire. How can this be when it takes the impulse 1 foot per second to get to that far end? Topology as defined by Ron would erroneously conclude impulse first appears where impulse was first applied to wire.

Why do we know that topology not relevant? Its a simple second year course called E-M fields. One first learned basic concepts before promoting rubbish such as topology and 'faraday cage'.

Notice that Ron Reugh also cannot provide MOV datasheets to demonstrate protection by vaporization. He is typical of those who would recommend plug-in protectors. Facts remain unchallenged: a surge protector that vaporizes during a surge is ineffective and even violates the MOV manufacturer's own specifications. Ron's best technical response:

R>> Please feel free to show us an MOV datasheet that says

Reply to
w_tom

Reply to
w_tom

If a computer PSU fails then I have heard that it may (or may not) blow the mainboard and perhaps various other components with a power surge or soemthing like that.

It seems that better PSUs are designed so that when they fail they have some circuitry which protects the other components in the PC.

Is this failsafe feature of the PSU I am referring to pretty much the same feature you are referring to? Or are they separate features?

Does anyone know how common it is to get this failsafe feature in a PSU?

Reply to
J.J.

I'l bite:

I think I understant FAT systems.

But the only thing I "think" I know about the NTFS is that, effectively, the system first makes a record of what it is about to do, then it does it, and then it either erases the original record or somehow marks it.

SO: can someone "explain" the NTFS to me. (Please don't tell me to "look it up.")

Reply to
John Gilmer

Reference Microsoft :)

"Because you didn't shut down Windows properly, Scandisk is now trashing your disk to complete the job.

In future, always shut down Windows properly"

Scandisk is not *always* going to pull your nuts out of the fire after a power interruption. In fact, it might make things worse :)

Wouldn't you *expect* data corruption, if the system was writing/about to write cached data, and the mains power went off?

You don't need references to figure out that it's a bad idea to just lose power in an uncontrolled way.

Reply to
Mike

In sci.physics, w_tom

wrote on Sat, 10 Jul 2004 02:06:11 -0400 :

Erm, 1 foot per *nano*second. Light speed.

Perhaps it's somewhat less than that; AIUI electric current is along the lines of 2/3 c, but it's still pretty darned fast.

[rest snipped]
Reply to
The Ghost In The Machine

You can't even define "impulse".

Now you've self contradicted and imploded. Ask Albert.

Reply to
Ron Reaugh

Your wacko claims have already been refuted by my citation earlier in this thread. APC does include "common mode" as I cited.

Reply to
Ron Reaugh

In article , Ron Reaugh writes

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

Reply to
Mike Tomlinson

Or RieserFS. But that is used by OS's other than Gate$ Lemingware! :-)

Reply to
No Spam

In sci.physics, John Gilmer

wrote on Sat, 10 Jul 2004 10:53:27 -0400 :

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

Reply to
The Ghost In The Machine

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.

Reply to
JM

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.

OK.

Which means ...

OK

Huh?

Neat!

OK

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.

OK

Sorry, you have just asked me to think and work harder than I care to.

Reply to
John Gilmer

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."

Reply to
ehsjr

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 >

Reply to
w_tom

Nice try liar.

Reply to
Ron Reaugh

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