Behold, Wim Ton signalled from keyed 4-1000A filament:

Anyone got any high-current/low-voltage horror stories they'd care to
share?

I friend who is a power IC developer told me about FETs being blown up
by the enery stored in the self inductance of the IC bond wire.

Wim

That's why FET is known by many to stand for Fire Emitting Transistor ;-)

--
Gregg t3h g33k
"Ratings are for transistors....tubes have guidelines"
http://geek.scorpiorising.ca

On Tue, 17 Aug 2004 05:39:28 GMT, Gregg wrote:

Behold, Wim Ton signalled from keyed 4-1000A filament:

Anyone got any high-current/low-voltage horror stories they'd care to
share?

I friend who is a power IC developer told me about FETs being blown up
by the enery stored in the self inductance of the IC bond wire.

Wim

That's why FET is known by many to stand for Fire Emitting Transistor ;-)

Not so much your GP FETs, but power MOSFETs, certainly. They do tend
to go 'pop' quite spectacularly.

--

"What is now proved was once only imagin'd." - William Blake, 1793.

On Tue, 17 Aug 2004 05:39:28 GMT, Gregg wrote:

Behold, Wim Ton signalled from keyed 4-1000A filament:

Anyone got any high-current/low-voltage horror stories they'd care to
share?

You should see a 440 RMS working volt 50,000 Joule MOV on a 600 amp
440 line that has received an over voltage spike.

The only thing left are the connecting wires and they are pointed
straight out. They are blinding if you happen to be looking at one
when it blows, or deafening if you are near. They'd put any 12 gauge
shotgun to shame.

These things are about 3 X 4 inches and just shy of an inch thick.
Used across a pair of 1200 VAC 1200A (as I recall) SCRs (Thyristors)

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com
I friend who is a power IC developer told me about FETs being blown up
by the enery stored in the self inductance of the IC bond wire.

Wim

That's why FET is known by many to stand for Fire Emitting Transistor ;-)

Back in the 60's I recall being at a party where everyone had too much
to drink and some YL's car would not start. The 'guys' went out to help
and checked the battery water level. The guy doing the checking could
not see as it was dark and asked for light. He was talking about a
flashlight and a helping hand showed up with a Zippo lighter. The
battery exploded! Very lucky none were killed or blinded.

In message , Paul Burridge
writes
Hi all,

Anyone got any high-current/low-voltage horror stories they'd care to
share? You know; where your messin' about with a car battery or
something like that and forget to take your watch off or whatever.

p.
Although I knew how crowbar protection worked on PSUs I was shown in a
dramatic way when I used a bench PSU to charge a car battery, for what
ever reason the crowbar operated and put a short across the battery,
lots of bright white wire and smoke for a few seconds.
A colleague of mine was a vehicle radio fitter and always wore metal
watch straps, until the day one bridged a battery supply and chassis. He
always wears a leather strap now and takes his watch off before working.
How more of us are not maimed or killed I'm not sure.
--
Bill

My story may not be extremely spectacular, but I think it has a rather
amusing moral...

I had for a number of years not bothered screwing down the top cover of my
13.8VDC 10A power supply, for whatever reason. Of course, every so often
the top cover would move and expose the inside working of the supply, but
that wasn't really a problem!(?)

Then one day, while doing my electronics trade course, we moved to the
subject of AC safety and how not to fry yourself! Very interesting lesson
and I scored 100% in the final exam for that subject.

Then I came home, rather pleased, reached down to switch off my power
supply, and promptly shorted the 240V AC main switch with my finger! What
was that about AC electrical safety again????

----

Another event, some years later, I was working on a tape deck on my
workbench. I had to reach over the tape deck to get a screwdriver from the
back of the bench, but of course I forgot it was still pluged in and
promptly shorted the AC transformer inout with my forearm...

Luckily for me we had just installed earth leakage breakers and it didn't
take long for it to trip... After that, whenever someone asked me "how long
do these breakers take to cut out" I would always answer with "oh, about
ARRRGG"

Cheers

Martin, VK2UMJ

My dad tells a story of his days working as a maintenence engineer in
a building where the power was carried along exposed buss bars.
Another worker had a screwdriver in his back pocket and backed into a
buss, blowing himself across the room and leaving a notable set of
scars from the molten screwdriver blade.

High school.
My buddy Pete has one of those continuous AC electrical outlets on the side
of his desk. You know. Two continuous brass strips in a foot long plastic
housing with two slots, into which you shove the (older two bladed) plug.

Well, one day he needed some line cord, which he ALSO had hanging on the
peg-board on the side of his desk
SO... He reaches around the end...grabs some line cord and proceeds to cut
off a piece with scissors...

Blam! ... notched scissors!

Outlet strip had the same kind of brown, two conductor cord.
--
Steve N, K,9;d, c. i My email has no u's.


"Mike Silva" wrote in message
m...
My dad tells a story of his days working as a maintenence engineer in
a building where the power was carried along exposed buss bars.
Another worker had a screwdriver in his back pocket and backed into a
buss, blowing himself across the room and leaving a notable set of
scars from the molten screwdriver blade.

In message , Steve Nosko
writes

SO... He reaches around the end...grabs some line cord and proceeds to cut
off a piece with scissors...

Blam! ... notched scissors!

On a vaguely similar line my father was rewiring an outside building and
carefully removed all the fuses from the fuse box before cutting out all
the old cabling. He then came across a cable he had forgotten and cut
this too, BANG!! It was the input to the fuse box. One very badly melted
pair of cutters and a rather startled father.
--
Bill

Bill wrote:
In message , Steve Nosko
writes

SO... He reaches around the end...grabs some line cord and proceeds to cut
off a piece with scissors...

Blam! ... notched scissors!

On a vaguely similar line my father was rewiring an outside building and
carefully removed all the fuses from the fuse box before cutting out all
the old cabling. He then came across a cable he had forgotten and cut
this too, BANG!! It was the input to the fuse box. One very badly melted
pair of cutters and a rather startled father.

I gotta. I just gotta.

About 25 years back, I was a new systems programmer for a government
agency which I'll cleverly call WeBuildHighways. Our sister shop, the
Department of inHuman Services, was fairly close, and we spent a fair
amount of time visiting and swapping hints and kinks.

One day I was there while some remodeling was being done: an old door
wsa being blocked and a new one cut. I heard a Skilsaw fire up, saw a
blade movingd ownward, and cringed: there was a quad-box about a foot
below the blade and in its path.

My counterpar was a bit quicker, and shouted "Turn Off All Your
Terminals RIGHT _NOW_!!" -- just before the blue flash and the great
dark silence.

This was before PCs, and so we only lost some 3270 terminal sessions
to the mainframe. It was ... interesting.

Another time I'll tell about The Guy Who Blew Himself Through The Door.

--
Mike Andrews

Tired old sysadmin