Re: Safety training..

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: tesla-at-lists.symmetric-dot-net 

Good stories are fun, but as you say, you need a good unexpected shock to
really learn anything.

Give the new folks something deceptive like a carboard box throw away
camera with built in flash that was recently used to take apart. They will
get fingers or hands across the cap in no time. It's a good lesson. Nobody
fears a paper camera. Large flashes will destroy a screwdriver tip and
burn you from the metal sparks that fly away.

fun stuff.

KEN


On Fri, 30 Jul 2004, Tesla list wrote:

 > Original poster: "Jim Lux" <jimlux-at-earthlink-dot-net>
 >
 > An interesting issue has come up at work, and I think the folks on this list
 > will have valuable insights.  You can send them to me off list if you like,
 > but they might be interesting to the whole list.
 >
 > Here's the deal..
 >
 > At work (Jet Propulsion Lab), we work with a variety of high power RF
 > sources (usually microwave, but also HF). We've got a whole herd of young,
 > bright engineers working on things like this that have never had HV
 > experience.  Unlike myself and my contemporaries (and, probably, most of the
 > people on this list), they have not had that "fundamental life changing
 > experience" of getting shocked as a youth, and as a result, do not (in my
 > opinion) have adequate respect for the "get close and it will reach out and
 > kill you" nature of these things.
 >
 > One older engineer commented that when he started working at a large
 > company, one of the senior engineers had taken him down into the lab where
 > they were doing high power modulators and showed him these two foot marks
 > burned into the tile floor.  They were from someone who had reached into a
 > piece of equipment that he had thought was safe, but wasn't.
 >
 > My group supervisor had an experience as a 10 year old plugging zip cord
 > into the wall socket to measure the voltage on a panel meter he was holding
 > in his hand (in 220V land!).
 >
 > A good friend of mine who knew nothing about electronics had a life changing
 > experience when I suggested that the 300 W tabletop plasma etcher he was
 > cleaning might have significant stored energy, and that he should think
 > about shorting the caps out before working on it. (I walked out of the room
 > to my office, heard a very loud bang, and saw my friend holding a
 > screwdriver with an amazingly large chunk knocked out if it, and very, very
 > wide eyes.  Quote: "And I had my hand in there before you came in the
 > room!")
 >
 > I had more zaps that I care to remember as a kid standing in bare feet in
 > the garage working on low voltage power supplies, but being careless about
 > the 110V wiring.  To this day, I don't even reach into TTL circuitry with
 > both hands.
 >
 >
 > All of us 40 and olders have similar experiences... the 30 and unders do
 > not.  They haven't had that "oh my gosh, I could have died" experience.
 >
 > So... here's the's question. How can we come up with some sort of suitably
 > visceral training.  When I started working with really HV (50 kV+), an old
 > guy (always a good sign in HV workers) suggested that I get a big Van
 > deGraaff and fool with it.  No kidding... you get within a meter and the
 > hair literally stands up on your arm and you get zapped a couple times when
 > you don't expect it..  Less than a joule, but it stings, and you remember
 > it.
 >
 > At work, it's even more insidious, because we're working with high power
 > microwaves (although the 1kV, 10 Amp supply for the HF amplifier gives me
 > the willies, but unfortunately, it doesn't do the same for the young
 > engineer working with it) which you can't see, or feel, until it's too late
 > (no evil hiss of corona, etc.).  That whole, oops the waveguide flange
 > wasn't tightened, etc. kind of thing. (or the, don't look into the open
 > waveguide with your remaining good eye, thing).
 >
 > What I'm looking for is good ways to give people that "if I'm not careful,
 > I, or someone else, will die" feeling.
 >
 >
 >