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> [And more importantly, how in the name of God does a device which only has
> access to a few milliwatts manage to get warm enough to physically melt??]
Chips normally draw milliwatts, they have access to much more.
The power supply is something like 500+ watts transient until a
fuse pops or something. A soldering iron draws around 20 watts...
so if you are drawing 200 watts (normal operation) it's equivalent
to running 10 soldering irons.
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"stbenge" <stb### [at] hotmail com> wrote in message
news:4831eb31@news.povray.org...
> I guess these are the reasons I unplug my computer from both wall and
> phone line during a thunderstorm...
>
> Sam
I started doing this after loosing a Kenwood AV controller and it was on a
GOOD surge protector.
Haven't lost any computers but the moment of first flicker everything gets
unplugged from the wall.
I guess that just proves that it's not nice to fool with mother nature!
Jim
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"stbenge" <stb### [at] hotmailcom> wrote in message
news:4831eb31@news.povray.org...
>
> I guess these are the reasons I unplug my computer from both wall and
> phone line during a thunderstorm...
My parent's house is at the top of a hill in a very open area. Until
recently their house was the highest thing for a couple km in any direction.
Add that to the frequency and intensity of thunderstorms in this part of the
world in summer and you see why they tended to get hit often.
They were very grateful when the neighbour put up a thatched roof and
installed a lightnng rod.
I live is a different area and I have 4 churches very near, all with
lighning rods. I seldom bother to unplug anything in a storm. So far, no
casualties from lighning
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> one of the PCI cards
...
> [And more importantly, how in the name of God does a device which only has
> access to a few milliwatts manage to get warm enough to physically melt??]
Where in the name of God did you get the idea that a PCI card only has
access to a few milliwatts? A quick Google told me the specification says
it can draw up to 25 W, so I imagine it can draw probably up to 30 W or more
on most motherboards.
30 W is easily enough to fry a chip.
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scott wrote:
> Where in the name of God did you get the idea that a PCI card only has
> access to a few milliwatts?
PCI devices are all extremely low power? Why would they design an
interface that can supply massively more power than necessary?
> A quick Google told me the specification
> says it can draw up to 25 W, so I imagine it can draw probably up to 30
> W or more on most motherboards.
>
> 30 W is easily enough to fry a chip.
Interesting - in my experiments, devices that are supposed to heat
things tend to be rated into kW...
--
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*
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> Interesting - in my experiments, devices that are supposed to heat things
> tend to be rated into kW...
See how long you can hold on to a 60 W light bulb for after you switch it
on...
Now imagine all that power concentrated into a tiny area inside a plastic
case.
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>> Interesting - in my experiments, devices that are supposed to heat
>> things tend to be rated into kW...
>
> See how long you can hold on to a 60 W light bulb for after you switch
> it on...
>
> Now imagine all that power concentrated into a tiny area inside a
> plastic case.
Mmm, crispy...
So, how come the entire board isn't melted? Just one little chip?
Presumably all that current had to get *in* to the board somehow...
--
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*
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> So, how come the entire board isn't melted? Just one little chip?
> Presumably all that current had to get *in* to the board somehow...
Of course, but presumably the PCB tracks have low enough resistance not to
instantly melt the PCB when a couple of amps goes through them. The same
can't be said for the tiny tiny wires inside an IC. Remember, heating is
due to power not current.
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On Tue, 20 May 2008 11:46:48 +0200, "scott" <sco### [at] scottcom> wrote:
>Remember, heating is
>due to power not current.
>
P = I^2 * R :)
--
Regards
Stephen
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scott wrote:
> Remember, heating is due to power not current.
That's interesting - this is the first I've heard of this. I thought
*all* electric effects are due to current?
--
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*
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