"Kristy Ogilvie" wrote in message
news
On Sun, 16 Dec 2018 19:53:06 -0000, Rod Speed
wrote:



"Kristy Ogilvie" wrote in message
news
On Sun, 16 Dec 2018 12:24:31 -0000, tony sayer
wrote:

In article , Kristy Ogilvie
scribeth thus
I once got a bit of grit in my eye that I couldn't dislodge (after DIY
plasterboard work I think), it was damn annoying. After 3 days of it
becoming
increasingly irritating, I went to Specsavers and they washed it out
free of
charge, and also gave me an eye test free of charge (presumably both
in
the hope
they could sell me expensive specs). But my eyesight was
"surprisingly
perfect
for a 40 year old - more like that of a teenager". I guess I never
grew
up :-)

I only saw the effects twice - not sure where the lightning came in,
but
a row
of 4 computers in a youth club had their soundcards fried (literally
black in
places). Apart from short speaker cables to little computer speakers,
I'm not
sure why the lightning would have gone in that way. The network cards
were
fine, but then they tend to have surge arrestors (spark gaps) in them.
Nothing
else on the computers were damaged. The other time was the network
card
in a
computer in someone's house - that could have been the phone line,
although he
reckoned a small fork of the lightning came THROUGH the house and
landed
on the
phone cable running along the hall (his computer was fairly central in
the
building).


Take it from me spark gaps where the voltages and currents that are in
a
lightning strike as mere piffling things, thats why we use a lot of
heavy cross section Ally, used to be copper but the scrotes came for
that, all in order to shunt these currents around that what we need to
protect!...

Well not much would shield from a full strike,

TV transmitter towers do handle those fine.
Expensive to do those tho.

but often you get stray edges/forks of a strike getting through wires
into
computers, so a spark gap takes that off.

Not convinced that it does now with modern electronics.
Works fine for primitive non electronic phones tho.

https://www.dehn-usa.com/sites/defau...e-ethernet.pdf

If you got the main strike of lightning into your computer, the whole
thing would literally explode

They don't actually.

Probably because it's rare for lightning to directly hit a computer.

Nope, because there is nothing that explodes when that
much current goes thru it. The most you get is some of
the traces blown off, but that's not an explosion.

They don't tend to be operated outside on top of a hill.

Even when they are, they don't explode when struck by lightning.

People don't either and some of them do get struck by lightning.

- just look at trees that were directly hit, they split in two,
explosively.

That's due to an effect you don't see with computers,
the sap vaporising and that gas blowing the trunk apart.

Pretty much anything will explode when huge currents go through it.

How odd that we don't have even a single example of
an exploded human after it has been struck by lightning.

The capacitors for a start - as a kid I used to overvolt them for nice
little fireworks.

That's not an explosion.