On Sun, 15 Aug 2004 12:50:28 -0400, Ken Scharf hath writ:

Well there was this guy changing batteries on a golf cart.
Had 6 very large 6 volt storage batteries wired in series.
He was using a ratchet wrench to remove the battery contact
clamps and while detaching the most postive end first (!)
the ratchet handle touched the frame of the golf cart.

Ever see a Sears ratchet glowing WHITE HOT?

Ya, but... You can take it back and they'll replace it. HI!HI!

Jonesy
--
| Marvin L Jones | jonz | W3DHJ | linux
| Gunnison, Colorado | @ | Jonesy | OS/2 __
| 7,703' -- 2,345m | config.com | DM68mn SK

On 15 Aug 2004 18:17:32 GMT, Allodoxaphobia
wrote:

On Sun, 15 Aug 2004 12:50:28 -0400, Ken Scharf hath writ:

Well there was this guy changing batteries on a golf cart.
Had 6 very large 6 volt storage batteries wired in series.
He was using a ratchet wrench to remove the battery contact
clamps and while detaching the most postive end first (!)
the ratchet handle touched the frame of the golf cart.

Ever see a Sears ratchet glowing WHITE HOT?

Ya, but... You can take it back and they'll replace it. HI!HI!

Only if you don't melt the part that says "Craftsman".

Happy trails,
Gary (net.yogi.bear)
------------------------------------------------
at the 51st percentile of ursine intelligence

Gary D. Schwartz, Needham, MA, USA
Please reply to: garyDOTschwartzATpoboxDOTcom

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Allodoxaphobia wrote in
:

Ever see a Sears ratchet glowing WHITE HOT?

Ya, but... You can take it back and they'll replace it. HI!HI!

They do insist that all tools be cooled well below the point of
emitting visible light before return, though.


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Paul Burridge wrote:

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.

Though there is considerable voltage involved in the production of the
currents involved, it is the (forces of the magnetic field of the)
current that crushes the coins.
http://webpages.charter.net/tesla/crushed_coin.htm
--
John Popelish

On Sun, 15 Aug 2004 12:01:14 +0100, Paul Burridge
wrote:

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.

I did once work with this sort of power, at a company which was making
superconductors. We had to test various samples at high current/low
voltage to determine some of the properties, while they were submerged
in various liquified gases.

One project involved setting up a two-module 1000 watt DC power
supply. I "wired" them together using copper bar stock 1" by 1/4",
bent to fit the terminals, and plated with silver for lower contact
resistance. The connection to the samples was with 2 ought welding
cable, which was about 1-1/8" in diameter with insulation.

I have also worked with high voltage RF up to 20 kV, but that is
another story.

The general rule is when you are working with KIL-o-amps, KIL-o-volts,
or KIL-o-watts, is to make sure you don't get KILL-ed.

Happy trails,
Gary (net.yogi.bear)
------------------------------------------------
at the 51st percentile of ursine intelligence

Gary D. Schwartz, Needham, MA, USA
Please reply to: garyDOTschwartzATpoboxDOTcom

Remember an old article in popular electronic, back from 1960's,

young boy wanted to help his girl nextdoor with a wart on her hand,
bright as he was, he thought he could use the hv from his pops hf rig
to burn off said wart.... well, she let out this scream that almost
broke the sound barrier and he got his butt wacked big time.

The wart did get removed !

j


Paul wrote:

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.
--

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

In 1982, I was about 20 I guess and working for Dentron Radio as a tech. For
no other reason than being careless, as I was normally on high alert when
working on the amps, I discharged a fully charged bank of filtercaps in a
Clipperton L from the left hand to the right.

I had tunnel vision for a couple seconds, fell to the ground as co-workers
rushed to my side. Short of breath and dizzy I began to sweat profusely. I
was ill for about a half hour then both arms began to ache as if I had been
pummeled with a baseball bat.

I have been zapped a few times since then but never ever will I allow IT to
flow across my chest again, that event scared the hell out of me and I was a
strapping young lad in good shape. Today the same hit would kill me, I'm
sure of it.

This could also explain my devout interest in QRP today!

Tim

Paul Burridge wrote:
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.

This dates thirty years back: I was about ten years old. My father did
occasionally charge car batteries in the basement of our house. The
output of the charger was short cable with a broken cigarette lighter
plug. He did connect the battery to be charged with a pair of jumper
cables connected to it.
I was doing something in the room, when there was a big spark and some
smoke started to appear. I immediately disconnected the charger from the
mains as he explained to us that this was all we had to do to remove all
electricity from a device. I then went to search for him to tell him
what happened. When we came back the room was full of smoke and all what
was left of the jumper cables was some melted plastic. The copper was
all gone !

Markus

Paul Burridge wrote:
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.

When I graduated from highschool, 1967, I started work for a company
called Standard Plastic Products. What we really did was make those
plastic and cardboard Barbie cases. These were heat sealed with
RF Energy. Lots of it.

The work area had about 50 sealing machines. These units were Class-C
RF oscillators and ranged from 25 to 60 KW. Yes, that is Kilo Watts.
Each unit had a large ceramic tube that had a base of around 6 - 8
inches in diameter. The larger units had tubes with large heat sink
hats which required a chimney to remove the heat. The RF energy was
applied to two copper platens that performed the sealing.

My job, along with three other techs, was to keep these machines
working. The most common problem with these things was blowing fuses,
dirty coupling capacitor clips, and some pretty spectacular blowouts
on the platens when the material got too thin.

The real problem was that, you had to reach into the units from the
back to get to the fuses or the coupling caps. The units had
power interlocks, so you couldn't activate with the back open
This was suppose to disable all power, remove the plate voltage,
and allow any charge to bleed off. But there were a few units where
the bleeder circuits did not work properly. This usually left a few
thousand volts on the plates of the tubes. You learned real quickly
to grip your adjustable wrench with your cardboard fuse pullers and
short the plate to ground. It was a heck of a blast and after 2 or
3 times, the unit was safe to work on.

Although I never heard of anyone actually comming in contact with
the voltage, because we were always on our toes, but I am sure that
it would have done some damage. I doubt the government would let
them get away with something like that now.

And you want to talk about QRM, these things oscillated around 27 MHz.

--
Martin E. Meserve

http://www.k7mem.150m.com

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