Are mains surge protectors needed in the UK?

"Lem" wrote in message
...
"half_pint" wrote:

And if you are saying that semi conductor devices are
inherently sensitive to current then obviously we would make
fuses out of them. However semiconductors are make out of
silicone which has an extremly high melting point. (we are
basically talking about sand) indeed silicone has replaced
asbestos as a safer heat resistant material.


Are you perhaps confusing silicon with silicone?`

Welll prehaps you are, silicone is based upon silicon
just as many semiconductors are based upon silicon.
Silicone like semiconductors in ICs does not occur naturally
however both are based upon silicon (or similar) and have
very high melting points.



http://www.candochefs.com/silbakmat1.html

" Use in up to 900 degrees F! "

Obvioulsy fuses are *designed* to melt quickly
at low temperatures.

Semiconductors materials are probably never damaged
by heat, at least not untill long after the metalic contacts
have vapourised.

On Sun, 11 Jul 2004 18:22:08 UTC, "half_pint"
wrote:


Silicone like semiconductors in ICs does not occur naturally
however both are based upon silicon (or similar) and have
very high melting points.

And they are completely different. Silicon is an element, and silicone
is a synthetic polymer compound. Therefore, saying that semiconductors
use silicone is rubbish.

--
Bob Eager
begin a new life...dump Windows!

"David Maynard" wrote in message
...
half_pint wrote:

But electronic devices are not connected directly to the mains they
are connected to a power supply which is *designed* to copy
with large cueernts.

I suppose you think that means something but it's irrelevant to the
point
that electronic devices react to electrical faults hundreds of times

faster

than any fuse can. More to the point, any current that could possibly
blow
a fuse is the RESULT of a failure which, by definition, means the fuse
cannot 'protect' from it as it's already happened.


No we are talking about a surge in current from outside the house

No, we're talking about a voltage surge.

Voltage never causes device failure,

so to speak. That surge must go through the fuse first, strictly
speaking,
well, at leaaast at the same time anyway.

There will be no current unless something conducts.

Brilliant!!!


I.E. If there were no devices plugged in (or wired in) the only effect
would be a voltage spike on the interior power lines, but no current flow
per see (besides leakage).

And no current flow = no damage.


If, however, a susceptible device is connected to the power line and the
voltage spike is sufficient to cause electrical breakdown then the device
fails and may pull excessive current as a result of the failure, which, if
severe enough, will blow the fuse. But the failure has already occurred by
the time the fuse sees anything, much less blows.

Only current flow causes damage, current flow blows fuses.
A main spike hits the robust components of the PSU first
these are not sensitive to high voltages, infact the voltages inside
them are dangerous to humans,



OK if you connect one leg of your 3GHz pentuim to the
mains live connection and the other leg to earth you will probably

damage it

but I am not recommending that.



And it's inherent to the nature of electronics.
By the time an electronic device is pulling excessive current whatever

is

at fault inside has long since gone to the happy hunting grounds, or

else

it would not be pulling excessive current. And there's nothing you can

do


about it by 'sizing' the external fuse as the failed device could be a
100mw component inside a 200 watt computer where the normal operating

power


fluctuations are hundreds of times larger.



I dount there are many 100mw components in a PS and even if there
were and they did blow they would protect your computer.

For that to even begin to make sense you'd first have to consider a
blown
power supply as the device still 'working', but I doubt most people do.

Further, I have no idea what makes you think a 'blown' component in the

PSU

will 'protect' the computer. All one need imagine is the reference
voltage
zener blowing, resulting in lord knows what voltage being thrown into
the
system and destroying massive numbers of components.


A zener diode is already 'blown' so to speak, thats how they work.

No, it isn't.

The voltage across them is basically the same whatever the input
voltage.

An obvious contradiction, as stated.

Rubbish that is how they are designed to work!!


A zener conducts when the voltage across it reaches a certain level,
otherwise is does not conduct, and the source better be current limited,
most commonly by a series resistor, or else the zener will self destruct.
In that case, by over heating.

Ans of course they are always current limited by a series resirtor in
appliances.


Essentially it is a grain of sand,

Not hardly.

I am afraid it is.


its not going to melt,

'Melting' has nothing to do with it.

What?


at least not
before
other metal components vapourise. And the first component to vapourise
will be the fuse in the plug, you can be sure of that.

No offense but you really don't understand semi-conductors at all.


You are maing no sense ar all.


That is, of course,
why all decent PSUs include over voltage protection on the power rails.


Ah hah!!


And
while you may gleefully scream "ah hah!," as if that means something to
your case, it isn't done with fuses because fuses are too slow to
protect
electronic components.


I think you will find 99% of surge protectors contain a fuse, which is a
bit
odd really if they are surplus to requirements?

No one ever said they were 'surplus'. The problem is you don't understand
the nature of electronics and the purpose of various protection devices.

I do

A fuse blows on a sustained current fault and breaks the connection: a
preferable situation to continuing to draw fault current because, for one,
it prevents fires.

That has nothing to do with 'protecting' what is already a damaged device
causing the current fault.

You don't really understand electricity do you?


The issue isn't 'where' the fault occurs in the device but that a fuse
simply cannot 'protect' from it (voltage induced failure).


However before it did blow it would probably required a
several fold increase in current for a substained period which
would obviously blow the fuse first.

This is where you are sorely mistaken as you seem to think that the only
way any device, of any kind, fails is by current induced heating but
that
is simply not the case with electronic devices. Too much voltage, as
perhaps induced by a surge, will instantly destroy semi-conductor
components; after which they may simply do nothing or, more common, draw
excessive current. At which point, anything a 'fuse' detects is long
since
after the fact.

No that current has to come in via the fuse which is designed to fail as
quickly
as possible, as opposed to other components which are designed *not* to
fail.

You're never going to understand it till you get it out of your head that
'excessive current' is the only thing that damages semi-conductors.

Heat is the only souce of damage, and current not voltage
produces heat.


(Heat can destroy them too but that isn't the mode we're talking about

with

surge protection)


And if you are saying that semi conductor devices are inherently
sensitive to current then obviously we would make fuses out of them.

It is your mistaken notion that only 'current' causes failure that leads
you to invalid assumptions.


But I am right of course, *only* current *ever* causes electrical
failures.
A semiconductor device, or any electrical device will work quite
happilly
a 1 billion volts.

Surely you jest.

Why in the word do you think power supplies, much less multi-voltage
units,
even exist if electronics works 'quite happily' at just any old voltage?


I think you missed the point.


However semiconductors are make out of silicone which has
an extremly high melting point.

Which is irrelevant because that is not what causes device failure.


Heat is the only cause of device failure. Ever. Period.

Just plain wrong.

Really now, even your own decryption, as misguided as it is, contradicts
THAT absurdity because, if it were true, there would never ever be an
electronic failure, unless someone shoved it inside a 900F oven. And that
is clearly not the case.

You don't have to heat the whole device, the damage is usually localised


(we are basically talking about
sand) indeed silicone has replaced asbestos as a safer heat
resistant material.
http://www.candochefs.com/silbakmat1.html

" Use in up to 900 degrees F! "

Obvioulsy fuses are *designed* to melt quickly
at low temperatures.

Semiconductors materials are probably never damaged
by heat, at least not untill long after the metalic contacts have
vapourised.

'Melting' is not the failure mechanism of semi-conductor devices.


Yes it is.

No, it isn't. And I'd advise you to go learn something about
semi-conductors before you make such statements because they make it
rather
obvious you have no idea how they work.

I have every idea how they work, much more so than you.


And even if you did have a
'constant power consumption' electronic device, for which you could
'tightly' size a fuse, electronic components can, and do, go into
catastrophic failure hundreds of times faster than a fuse can blow.

Surge -- component failure -- excessive current -- fuse blows



They blow before the device draws enough current to be damaged, that
is
how they are designed.

That is certainly the myth. It is not, however, reality.


You don't have a huge backlog of expensive surge protectors to shift
by any chance?

I don't 'sell' anything nor is it any skin off my nose if your computer
is
damaged because you think a fuse will 'protect' it.

Nice try buddy, uk.comp.vendors, pull the other one, I wasn't born
yesterday.

I'm posting from alt.comp.hardware.pc-homebuilt.


There of dozen of devices in my home which contain IC's none has ever
failed due to a power surge, zilcho.

And you think that 'proves' what?

My point and my arguement, unsurprisingly.


There are also many IC's in my car which regularly gives me a big zap of
static electricity, I can assure you that the shock has effected me far
more
than
my car stereo etc....

Oh, really? And what were you doing with the case to these devices open so
that you were getting a 'static discharge' from the 'ICs'?

Still a huge voltage surge and no anti - surge device yet MIRACULOUSLY
ALL THOSE SENSITIVE DEVICES WERE TOTALLY UNDAMAGED
HOW STRANGE????????

But since you bring it up you could expand your horizons by doing a web
search on ICs and static electricity and, in particular, ESD protection.

Already have, not that I needed to, everything I found bacjed my
case.

Here's one to get you started:
http://www.informit.com/articles/art...21704&seqNum=3

"In general, MOS devices are sensitive to voltage spikes and
static-electricity discharges. This can cause many problems when you have
to replace MOS devices, especially complementary-symmetry metal-oxide
semiconductor (CMOS) devices. The level of static electricity on your body
is high enough to destroy the inputs of a CMOS device if you touch its
pins
with your fingers."

Basically irrelevant garbage, i could handle a million circuit board
without
causing any damage. A case of a little knowledge incorrectly applied.


I have also worked in enviroments where there are dozen's upon
dozens of computers, no surge protection and no failed computers.

Which you think 'proves' what?

My point.


I get the feeling that someone here is trying to shift a job lot of
surge
protectors on ebay, either that or having a larf.

Think I will go and take a look

Have fun.

I will

"Bob Eager" wrote in message
...
On Sun, 11 Jul 2004 18:22:08 UTC, "half_pint"
wrote:


Silicone like semiconductors in ICs does not occur naturally
however both are based upon silicon (or similar) and have
very high melting points.

And they are completely different. Silicon is an element, and silicone
is a synthetic polymer compound. Therefore, saying that semiconductors
use silicone is rubbish.


Thats why I never said that of course, except in a typo
I used silicone to illustrate the high metling point of silicon
based products. You try using both words a lot with out making
the samne typos.


--
Bob Eager

"Johannes H Andersen"
wrote in message
news:40F19174.AE670716@sizefitterlikneasfuongtuint gsjadfasejk.com...


half_pint wrote:

"Johannes H Andersen"
wrote in message
news:40F11D7F.CCB37EDF@sizefitterlikneasfuongtuint gsjadfasejk.com...


half_pint wrote:

[...]

As said before, voltages also kills semiconductor devices. Why do
you
think there are such things as electrostatic bags?

To protect semiconductors from static electricity as opposed to
mains electricity.

LOL! How much do you know about electricity?

I have forgotten far more than you will ever know.

Too bad your memory is like a sieve. You might have heard about electric
potential? Measured in Volt in both static and mains cases. A
semiconductor
such as a transistor must have the atoms organised in a particular way,
that result in energy bands the for controlled movements of charges
through
the lattice. The electrons are not free as in metals or carbon, if that
was
the case then the electrons would be able to move equally in all
directions
and the semiconductor would not do its job.

If you now increase the electric potential over the designed value, then
these delicate structures and the energy bands breaks down. This is not
the same thing as burning a fuse.

They are not delicate structures, no more than a grain of sand is delicate.
A zener diode, works by 'breaking down'. however it is not damaged
permanently it still will work as a normal diode with in its limits. there
is no permanent change in its functionality.

And nothing breaks down anyway it is normal operation at such vooltages.

half_pint wrote:

"Johannes H Andersen"
wrote in message
news:40F11D7F.CCB37EDF@sizefitterlikneasfuongtuint gsjadfasejk.com...


half_pint wrote:

[...]

As said before, voltages also kills semiconductor devices. Why do you
think there are such things as electrostatic bags?

To protect semiconductors from static electricity as opposed to
mains electricity.

LOL! How much do you know about electricity?

I have forgotten far more than you will ever know.

Too bad your memory is like a sieve. You might have heard about electric
potential? Measured in Volt in both static and mains cases. A semiconductor
such as a transistor must have the atoms organised in a particular way,
that result in energy bands the for controlled movements of charges through
the lattice. The electrons are not free as in metals or carbon, if that was
the case then the electrons would be able to move equally in all directions
and the semiconductor would not do its job.

If you now increase the electric potential over the designed value, then
these delicate structures and the energy bands breaks down. This is not
the same thing as burning a fuse.

half_pint wrote:

"David Maynard" wrote in message
...

half_pint wrote:


"Bob Eager" wrote in message
...


On Sat, 10 Jul 2004 21:43:19 UTC, "half_pint"
wrote:



But electronic devices are not connected directly to the mains they
are connected to a power supply which is *designed* to copy with
large cueernts.

But not *that* large...and they too contain semiconductor devices.



I dount there are many 100mw components in a PS and even if there
were and they did blow they would protect your computer. However
before it did blow it would probably required a several fold
increase in current for a substained period which would obviously
blow the fuse first.

For semiconductor devices, the sustained period is a lot shorter than
for a fuse.


No it isn't otherwise fuses would be made from semiconductors.



And if you are saying that semi conductor devices are inherently
sensitive to current then obviously we would make fuses out of them.
However semiconductors are make out of silicone which has

No, silicon. Not the same. How many semiconductor-packed breasts do
you know of?


I don't wear breast implants, but good luck with the 'op' anyway ;O)



Semiconductors materials are probably never damaged by heat, at
least not untill long after the metalic contacts have vapourised.

Perhaps not the base material, but semiconductor materials are a bit
more complex than that (hint: look up 'doping').


Maybe I should look up 'dope' :OP we are basically talking about very
stable elements, similar to silicon which are 'woven' into the silicon
lattice they will form a very stable structure.


And they're still nice 'stable elements' after the device has failed too,
it just isn't a working device anymore.


No because the metalic contacts have evapourated.
Replace the contacts and it would be fine.


chuckle

half_pint wrote:

"Johannes H Andersen"
wrote in message
news:40F19174.AE670716@sizefitterlikneasfuongtuint gsjadfasejk.com...


half_pint wrote:

"Johannes H Andersen"
wrote in message
news:40F11D7F.CCB37EDF@sizefitterlikneasfuongtuint gsjadfasejk.com...


half_pint wrote:

[...]

As said before, voltages also kills semiconductor devices. Why do
you
think there are such things as electrostatic bags?

To protect semiconductors from static electricity as opposed to
mains electricity.

LOL! How much do you know about electricity?

I have forgotten far more than you will ever know.

Too bad your memory is like a sieve. You might have heard about electric
potential? Measured in Volt in both static and mains cases. A
semiconductor
such as a transistor must have the atoms organised in a particular way,
that result in energy bands the for controlled movements of charges
through
the lattice. The electrons are not free as in metals or carbon, if that
was
the case then the electrons would be able to move equally in all
directions
and the semiconductor would not do its job.

If you now increase the electric potential over the designed value, then
these delicate structures and the energy bands breaks down. This is not
the same thing as burning a fuse.

They are not delicate structures, no more than a grain of sand is delicate.

What are you on about warp_saint?

A grain of sand is made of the the same raw material, but it's not a
transistor! Transistor silicon is carefully grown into an almost fault free
lattice. Impurity elements are then carefully inserted to establish the
energy bands. That way P and N materials are created.

A zener diode, works by 'breaking down'. however it is not damaged
permanently it still will work as a normal diode with in its limits. there
is no permanent change in its functionality.

A zener diode is designed with a Zener knee Voltage for the desired effect.
however the Zeener knee is inside the designed Voltage range. If you exceed
the designed Voltage, you blow the Zener diode for much the same reasons
that you'll blow a transistor. If you ever have experimented with electronics,
you'll have come across many duff transistors etc with no physical sign of
burns whatsoever, just dead because you have used the wrong voltage or used
the wrong polarity.

Elsewhere in this topic is a claim that fuses can prevent
surge damage. First put numbers to the claim. Surges
accomplish damage in microseconds. Fuses, circuit breakers,
and thermal links take milliseconds to open. How, is a fuse
suppose to stop what has already occurred well into the past?
It does not. Surges do not blow fuses. However fuses blow as
a result of damage created by the surge.

Mike previously posted:
Many good quality European surge protectors illuminate a
warning lamp to indicate when the protective devices have
degraded such that they are no longer effective and that the
protector should be replaced.

So we ask the MOV professionals to define "degraded". From
a Littelfuse application note AN9310:
A failed device is defined by a ±10% change in the
nominal varistor voltage at the 1mA point. This does
not imply a non-protecting device, but rather a device
whose clamping voltage has been slightly altered.
This is called "degraded". The threshold or let-through
voltage of 330 volts (as printed as required on surge
protectors boxes) changes to under 300 volts or over 360
volts. Protector will still work, but it has degraded and is
considered by manufacturer datasheets as failed.

Another and catastrophic failure mode is vaporization. This
is the totally unacceptable event when the MOV is grossly
undersized - operates beyond what manufacturer designed.

Again from Littelfuse application note AN9772:
Varistors initially fail in a short-circuit mode when
subjected to surges beyond their peak current/energy
ratings. They also short-circuit when operated at
steady-state voltages well beyond their voltage ratings.
This latter mode of stress may result in the eventual
open-circuiting of the device due to melting of the
lead solder joint. When the device fails in the shorted
mode ... a large amount of energy can be introduced,
causing mechanical rupture of the package accompanied by
expulsion of package material in both solid and gaseous
forms [also called vaporization] . Steps may be taken
to minimize this potential hazard by the following
techniques: 1) fusing the varistor to limit high fault
currents, ...

To meet the human safety requirements imposed by UL1449 2nd
edition, manufacturers install a thermal link as demonstrated
in a schematic from Mike Tomlinson. When does that thermal
link open? When the MOV is degraded? Of course not. The
thermal link only blows open when an MOV was so grossly
undersized as to short circuit and vaporized. Thermal link
blows when MOV operates well beyond what manufacturer
intended. This thermal link for human safety is necessary to
meet UL1449 2nd edition.

How can this be? Mike Tomlinson told us that surge
protectors:
... illuminate a warning lamp to indicate when the
protective devices have degraded ...
He even provided a schematic to show us the thermal link that
blows when MOV degrades!

A 330 volt MOV degraded so that it operates at 300 volts or
360 volts will blow the thermal fuse? Of course not. One
first has to believe Mike Tomlinson has been educated. As
demonstrated in a scary picture from Zerosurge, the MOVs can
even be removed and the indicator lamp says protector works
"OK":
http://www.zerosurge.com/HTML/movs.html
But then those MOVs did not fail catastrophically - blow the
thermal link. Indication lamp is to report catastrophic
failure.

For those who want to learn what that indicator light
reports: "OK" light can only report when surge protector was
so grossly undersized as to vaporize MOVs - the unacceptable
catastrophic failure in AN9772 and the reason why UL (an
organization dedicated to human safety) created UL1449 2nd
edition. So that a vaporizing MOV does not result in fire and
death, UL1449 requires that a catastrophically failing MOV not
threaten human life. Indicator lamp indicates that an
essential human safety fuse - a thermal link - has blown. It
indicates that the surge protector was grossly undersized as
to even blow its thermal link.

The normal failure mode for MOVs is defined by AN9310. A
degraded MOV will not blow any fuse because it does not short
circuit and vaporize. To blow the fuse, an MOV must become a
short to AC mains voltage for milliseconds. Aa degraded MOV
will not open (blow) the thermal disconnect device LK1. But a
catastrophically failed (short circuited) MOV will.

An MOV does not get hotter only because its let-through
voltage changes; is below 300 volts or above 360 volts. Lets
remember those numbers posted up to. Surges are microsecond
events. If they damage the MOV, then milliseconds of AC
electric cause the thermal link to fail. But a grossly
undersized MOV short circuits. Milliseconds later, AC
electric heats that damaged MOV, pushes too much current to
blow that thermal link, and illuminates that warning light
LP1.

That warning light will report a catastrophically failed
surge protector but can not report that a protector has
degraded. Light will report one type of failure and cannot
report a good surge protector.

A surge protector is only as effective as its earth ground.
Facts that don't change no matter what fancy lights report and
no matter how Mike Tomlinson insults others.

Mike Tomlinson wrote:
In article , w_tom
writes

This 'light' feature is so old in America that it was even
on surge protectors tested in PC Magazine in the 1980s. So
now you insult the US for importing Chinese 'junk'. Where in
that insult is a technical fact? How does that light work?

I've posted this before in another thread, but given that
you have the attention span of a mentally retarded goldfish,
am not surprised that you've already forgotten.

I assume you have basic understanding of electronics (though
I'm not counting on it, given your performance to date.)
Here's the circuit diagram and description of the plug-in
surge protector I use:
http://jasper.org.uk/w_tom_is_a_******/cct.jpg

Quote:
"The protection VDRs in this circuit have a thermal
disconnect which breaks link LK1 when either VDR has
reached the end of its life. Link LK1 under normal
operation is a short circuit but when opened due to
the thermal disconnect device, allows current to flow
via the lamp LP1 and the resistors R1 and R2, thus
illuminating LP1."

See! This surge protector fails in a controlled manner
and illuminates a lamp, instead of exploding messily
like the examples you cited in:
http://www.zerosurge.com/HTML/movs.html

half_pint wrote:

"David Maynard" wrote in message
...

half_pint wrote:


But electronic devices are not connected directly to the mains they
are connected to a power supply which is *designed* to copy
with large cueernts.

I suppose you think that means something but it's irrelevant to the

point

that electronic devices react to electrical faults hundreds of times

faster


than any fuse can. More to the point, any current that could possibly

blow

a fuse is the RESULT of a failure which, by definition, means the fuse
cannot 'protect' from it as it's already happened.


No we are talking about a surge in current from outside the house

No, we're talking about a voltage surge.


Voltage never causes device failure,

Research it and learn, or remain ignorant. Your choice.


so to speak. That surge must go through the fuse first, strictly

speaking,

well, at leaaast at the same time anyway.

There will be no current unless something conducts.


Brilliant!!!


I.E. If there were no devices plugged in (or wired in) the only effect
would be a voltage spike on the interior power lines, but no current flow
per see (besides leakage).


And no current flow = no damage.

Research electrostatic breakdown in semiconductors.


If, however, a susceptible device is connected to the power line and the
voltage spike is sufficient to cause electrical breakdown then the device
fails and may pull excessive current as a result of the failure, which, if
severe enough, will blow the fuse. But the failure has already occurred by
the time the fuse sees anything, much less blows.


Only current flow causes damage,

false.

current flow blows fuses.

true

A main spike hits the robust components of the PSU first

I suppose you want to ignore modem lines.

these are not sensitive to high voltages,

Depends on how high the voltage.

infact the voltages inside
them are dangerous to humans,

Some are; others aren't.

The fact of the matter is that you know nothing of which you speak.


OK if you connect one leg of your 3GHz pentuim to the
mains live connection and the other leg to earth you will probably

damage it


but I am not recommending that.




And it's inherent to the nature of electronics.
By the time an electronic device is pulling excessive current whatever

is


at fault inside has long since gone to the happy hunting grounds, or

else


it would not be pulling excessive current. And there's nothing you can

do


about it by 'sizing' the external fuse as the failed device could be a
100mw component inside a 200 watt computer where the normal operating

power



fluctuations are hundreds of times larger.



I dount there are many 100mw components in a PS and even if there
were and they did blow they would protect your computer.

For that to even begin to make sense you'd first have to consider a

blown

power supply as the device still 'working', but I doubt most people do.

Further, I have no idea what makes you think a 'blown' component in the

PSU


will 'protect' the computer. All one need imagine is the reference

voltage

zener blowing, resulting in lord knows what voltage being thrown into

the

system and destroying massive numbers of components.


A zener diode is already 'blown' so to speak, thats how they work.

No, it isn't.


The voltage across them is basically the same whatever the input

voltage.

An obvious contradiction, as stated.


Rubbish that is how they are designed to work!!

There cannot be "whatever the input voltage" to the one and only device in
your statement, the zener, if it's "the same."



A zener conducts when the voltage across it reaches a certain level,
otherwise is does not conduct, and the source better be current limited,
most commonly by a series resistor, or else the zener will self destruct.
In that case, by over heating.


Ans of course they are always current limited by a series resirtor in
appliances.

Well, no. That just happens to be the cheapest and most common means when
they're used as a simple voltage reference. It is not the only way they're
used.


Essentially it is a grain of sand,

Not hardly.


I am afraid it is.

You apparently haven't a clue.

It's like saying silicone is 'essentially sand', and has the properties of
sand. Or that glass is 'essentially sand', and has the properties of sand.

One has to go back to before even the days of alchemy to find such
absurdities promulgated as 'knowledge'.

its not going to melt,

'Melting' has nothing to do with it.

What?

Simple enough statement.


at least not
before
other metal components vapourise. And the first component to vapourise
will be the fuse in the plug, you can be sure of that.

No offense but you really don't understand semi-conductors at all.


You are maing no sense ar all.

That's probably how a medieval alchemist would feel about a discussion on
quantum mechanics, and for the same reason.

That is, of course,
why all decent PSUs include over voltage protection on the power rails.


Ah hah!!



And
while you may gleefully scream "ah hah!," as if that means something to
your case, it isn't done with fuses because fuses are too slow to

protect

electronic components.


I think you will find 99% of surge protectors contain a fuse, which is a

bit

odd really if they are surplus to requirements?

No one ever said they were 'surplus'. The problem is you don't understand
the nature of electronics and the purpose of various protection devices.


I do

It is obvious you don't and what's further obvious is that you refuse to
learn a thing about it.


A fuse blows on a sustained current fault and breaks the connection: a
preferable situation to continuing to draw fault current because, for one,
it prevents fires.

That has nothing to do with 'protecting' what is already a damaged device
causing the current fault.


You don't really understand electricity do you?

I have already provided you with corroborating authoritative sources for my
explanations.

I challenge you to provide one for your absurd contention that voltage
cannot damage semiconductors.




The issue isn't 'where' the fault occurs in the device but that a fuse
simply cannot 'protect' from it (voltage induced failure).



However before it did blow it would probably required a
several fold increase in current for a substained period which
would obviously blow the fuse first.

This is where you are sorely mistaken as you seem to think that the only
way any device, of any kind, fails is by current induced heating but

that

is simply not the case with electronic devices. Too much voltage, as
perhaps induced by a surge, will instantly destroy semi-conductor
components; after which they may simply do nothing or, more common, draw
excessive current. At which point, anything a 'fuse' detects is long

since

after the fact.

No that current has to come in via the fuse which is designed to fail as
quickly
as possible, as opposed to other components which are designed *not* to
fail.

You're never going to understand it till you get it out of your head that
'excessive current' is the only thing that damages semi-conductors.


Heat is the only souce of damage, and current not voltage
produces heat.

Wrong, and I've provided authoritative sources to corroborate it.

(Heat can destroy them too but that isn't the mode we're talking about

with


surge protection)



And if you are saying that semi conductor devices are inherently
sensitive to current then obviously we would make fuses out of them.

It is your mistaken notion that only 'current' causes failure that leads
you to invalid assumptions.


But I am right of course, *only* current *ever* causes electrical

failures.

A semiconductor device, or any electrical device will work quite

happilly

a 1 billion volts.

Surely you jest.

Why in the word do you think power supplies, much less multi-voltage

units,

even exist if electronics works 'quite happily' at just any old voltage?

I think you missed the point.

If you thought so that certainly doesn't elaborate, but don't bother as
I've had enough of your absurdities anyway.


However semiconductors are make out of silicone which has
an extremly high melting point.

Which is irrelevant because that is not what causes device failure.


Heat is the only cause of device failure. Ever. Period.

Just plain wrong.

Really now, even your own decryption, as misguided as it is, contradicts
THAT absurdity because, if it were true, there would never ever be an
electronic failure, unless someone shoved it inside a 900F oven. And that
is clearly not the case.


You don't have to heat the whole device, the damage is usually localised

You actually stumbled onto something that's halfway correct: you can have
localized heating. It's not, however, very relevant to the point because
the thermal conductivity of semiconductors won't allow so dramatic a
difference, when compared to your claimed '900F' destruction point, as to
matter to the illustration. So we need fools shoving them into 700F ovens,
instead of 900F ovens, before any device would ever fail. It is still an
absurdity.

Btw, the melting point of silicon isn't 900F, it's (much) higher, but I'm
using your numbers to illustrate that even your own 'theory' is irrational.


(we are basically talking about
sand) indeed silicone has replaced asbestos as a safer heat
resistant material.
http://www.candochefs.com/silbakmat1.html

" Use in up to 900 degrees F! "

Obvioulsy fuses are *designed* to melt quickly
at low temperatures.

Semiconductors materials are probably never damaged
by heat, at least not untill long after the metalic contacts have
vapourised.

'Melting' is not the failure mechanism of semi-conductor devices.


Yes it is.

No, it isn't. And I'd advise you to go learn something about
semi-conductors before you make such statements because they make it

rather

obvious you have no idea how they work.


I have every idea how they work, much more so than you.

Feel free to quote a text book, or some other authoritative source, that
supports your fantasies.


And even if you did have a
'constant power consumption' electronic device, for which you could
'tightly' size a fuse, electronic components can, and do, go into
catastrophic failure hundreds of times faster than a fuse can blow.

Surge -- component failure -- excessive current -- fuse blows




They blow before the device draws enough current to be damaged, that

is

how they are designed.

That is certainly the myth. It is not, however, reality.


You don't have a huge backlog of expensive surge protectors to shift
by any chance?

I don't 'sell' anything nor is it any skin off my nose if your computer

is

damaged because you think a fuse will 'protect' it.

Nice try buddy, uk.comp.vendors, pull the other one, I wasn't born
yesterday.

I'm posting from alt.comp.hardware.pc-homebuilt.



There of dozen of devices in my home which contain IC's none has ever
failed due to a power surge, zilcho.

And you think that 'proves' what?

My point and my arguement, unsurprisingly.

Since you made no 'point' there is nothing it could.


There are also many IC's in my car which regularly gives me a big zap of
static electricity, I can assure you that the shock has effected me far

more

than
my car stereo etc....

Oh, really? And what were you doing with the case to these devices open so
that you were getting a 'static discharge' from the 'ICs'?


Still a huge voltage surge and no anti - surge device yet MIRACULOUSLY
ALL THOSE SENSITIVE DEVICES WERE TOTALLY UNDAMAGED
HOW STRANGE????????

Not at all. It has nothing to do with ICs being 'immune' from static
voltage damage but it's obviously useless to attempt educating you about
anything.


But since you bring it up you could expand your horizons by doing a web
search on ICs and static electricity and, in particular, ESD protection.


Already have, not that I needed to, everything I found bacjed my
case.

ROTFLMAO


Here's one to get you started:
http://www.informit.com/articles/art...21704&seqNum=3

"In general, MOS devices are sensitive to voltage spikes and
static-electricity discharges. This can cause many problems when you have
to replace MOS devices, especially complementary-symmetry metal-oxide
semiconductor (CMOS) devices. The level of static electricity on your body
is high enough to destroy the inputs of a CMOS device if you touch its

pins

with your fingers."


Basically irrelevant garbage, i could handle a million circuit board
without
causing any damage.

I can too. It isn't 'fingers', it's whether your body has built up an
electrostatic charge and then you touch one.

Semiconductors, nowadays, also include protective devices inside them to
reduce the chances of ESD damage. that doesn't mean they're 'immune' from
it and it still proves the point of voltage causing damage.

A case of a little knowledge incorrectly applied.

An excellent description of yourself.


I have also worked in enviroments where there are dozen's upon
dozens of computers, no surge protection and no failed computers.

Which you think 'proves' what?

My point.

Which would be what?


I get the feeling that someone here is trying to shift a job lot of

surge

protectors on ebay, either that or having a larf.

Think I will go and take a look

Have fun.


I will

Didn't find anything, did ya? chuckle