>From: Ken Webster <spam_OUTKenTakeThisOuTWEBSTER.ORG>
>Reply-To: pic microcontroller discussion list <.....PICLISTKILLspam@spam@MITVMA.MIT.EDU>
>To: PICLISTKILLspamMITVMA.MIT.EDU
>Subject: Re: Fire in the Hole!!!
>Date: Wed, 26 Apr 2000 02:10:29 -0600
>
>That kinda reminds me of a time several years ago I got ahold of a big
>grab-bag of assorted tantalum capacitors.  They were supposedly all rated
>for 20V or higher and had a longer lead to denote the positive side but
>were
>otherwise unmarked.
>
>I happened to have a 12V lead-acid battery just sitting on my desk so I
>quickly whipped up a little test circuit on a protoboard with a load
>resistor and voltmeter so I could get a rough idea what size each capacitor
>was by counting how many seconds it took to discharge to about 9V.
>
>So I went about sorting the capacitors by briefly touching them to the 12V
>battery and then plunking them into the protoboard and counting the
>discharge time.
>
>Ok .. how many of you out there couldn't see this comming? ... After
>measuring a coupple dozen capacitors I was getting a bit bored and tired
>and
>spaced out a bit and touched one of the capacitors to the battery backwards
>...  -- POP! -- ... "What the?! ... Doh! .. Oh, well .. plenty more where
>that one came from, no big deal.  Cool!  The whole thing blew up!"  (all I
>had left was a coupple of leads barely held together by a bit of epoxy but
>the body of the capacitor was nowhere to be seen).
>
>I was just about to go back to sorting capacitors when I noticed a fire
>break out on the other end of my desk ... it seems that the little
>cylindrical core from inside the capacitor was quite hot and had landed on
>a
>stack of papers!  I'm just lucky that that thing flew over there instead of
>into my eye!
>
>Ken
>
>
> >Experiences should be shared.
> >
> >Just playing with a new small calibrator board over my computer desk,
> >taking measurements of the parts, board, LCD, battery etc, to draw the
> >physical position of the parts into the new instrument case...
> >disconnected the 4 x AA NiCad cells + wire from the circuit, just in
> >case, you know... taking measurements from the small 2x16 LCD unit,
> >entering it at the CorelDraw, here and there, then suddenly by the very
> >corner of the eye I saw something strange like moving at the side,
> >physically close to where was the disassembled unit.
> >
> >I am getting old, so somehow weak eye sometimes "see" things that
> >doesn't exist, you know, tired eyes and so on. But this thing was much
> >more than an eye tricky ilusion, blinked eyes to "clean" it better, the
> >strange thing was there, like moving as a ghost... then probably half
> >second after I noticed it by the first time, I turn my eyes back to the
> >board, LCD and things, my goodness, everything was on fire, fast one,
> >multiwire cable connecting LCD to the Board was transformed into a
> >bright lamp, papers below the cable was burning fast, in less than 2
> >seconds I got a real fire on my desk, lots of smoke... then I thought
> >laughing "Do I call 911 or just disconnect the damn battery + wire from
> >the LCD metal face? ... people at home asked me "What a hell is
> >happening? It finally worked? hehe.
> >
> >The real accident in the last 8 years. Cable is complete wasted, Checked
> >circuit board and LCD board intact... power it on... working.
> >
> >Thinking seriously to use a fuse in series with ALL my NiCad batteries
> >from now on... they are quite dangerously low impedance units.
> >
> >The experience was interesting, can you imagine it just happening with
> >nobody around?  Fire in the Hole!!!.
> >
> >Wagner.

> James Newton wrote:
> >Some day I'll have to tell you my ejection seat story.
>
> Eh?  This sounds good.  Please tell.
>
> I have another coupple of stories: (promise to shut up soon :o)
>
> When I was in junior high school I was playing around with DC-DC converters
> for xenon flash tubes.  After accidentally discovering that you can get
> quite a jolt from them, I pieced together a tiny "zapper" (for practical
> joke purposes) consisting of a 9V battery, 555 timer, small potcore
> transformer, rectifier, and capacitor.  The circuit would charge a .47uF
> capacitor to 1200V -- enough to momentarilly give you the sensation that
> your arm had been yanked out of its socket if you were unfortunate enough to
> touch it (at least that's how I remember it and I don't care to try it again
> to see if it hurts any less now that I'm grown up).
>
> One day I was toying with the idea of leaving the "zapper" hidden in a pants
> pocket and running a cable out under my clothes to a plug I could conceal in
> my hand.  I connected a coaxial cable to the "zapper" with a bannana plug on
> the end that I could touch my victims with.  To test it, I zapped various
> metal objects and marveled at the nifty sparks produced when the capacitor
> discharged.  One object I got especially nice sparks from was an iron pipe
> which I was stupid enough to pick up with my other hand to go show my friend
> in the other room.  The first coupple of times I zapped the pipe, I was
> lucky that the terminal that contacted the pipe first happened to be the
> same terminal as the shield on the coaxial cable.  The shield happened to be
> partially exposed on the end that connected to the zapper ... pants pockets
> are not thick enough to stop 1200V!  But then the other terminal made
> contact first!  YIPE!!!  I jumped halfway across the room and cussed like
> the devil!  My friend laughed his a** off!
>
> ---
> Another good story from roughly the same time (about the 7th grade) was when
> a friend of mine gave me a bag of assorted firecrackers.  Up until this time
> I had never encountered a cherry bomb and the only things I knew of that
> came in little spherical packages were smoke bombs.  So the first one I lit
> I just set on the ground and stepped back perhaps 2 or 3 feet.  I was
> wondering why my friend was running off so fast for a smoke bomb.  Boy was I
> surprised!!!  Them damn things sting when you're wearing shorts!
>
> ---
> Then there's the ultimate in stupidity -- when I was in 4th grade I once got
> a bunch of free plastic spoke decorations with a box of cereal or a happy
> meal or something.  I put them on the front wheel of my bike just for sh*ts
> and grins.  Then, as I was riding down a long hill at significant speed, I
> noticed a coupple of friends of mine a ways ahead and decided to get rid of
> the dorky spoke decorations before they see me with them.  To remove the
> spoke decorations I commenced to rubbing my foot up against the rapidly
> spinning wheel.  It was working quite well -- the little plastic thingys
> were flying everywhere.  Then the damndest thing happned!  Somehow my foot
> managed to become wedged between the spokes and the fork!  (who would have
> seen that comming?)  Then I had one of those "OH SH*T!" moments where time
> was going really slow and the bike was becomming more and more vertical and
> I was trying to jump off but couldn't because my foot was stuck!  Then the
> pavement came up to greet me and my bike landed on top of me and we both
> slid a ways resulting in a nice case of road-rash.  Luckilly I managed not
> to break any bones.  My original objective of avoiding embarasement was,
> well... not terribly successful (to put it mildly).

> -----Original Message-----
> From: Wagner Lipnharski [SMTP:KILLspamwagnerKILLspamUSTR.NET]
> Sent: Thursday, 27 April 2000 13:33
> To:   RemoveMEPICLISTTakeThisOuTMITVMA.MIT.EDU
> Subject:      Re: [OT] Re: Fire in the Hole!!!
>
> Sean Breheny wrote:
> >
> > Why should cement be conductive? Because it holds water well?
> >
> > Sean
> >
> > At 11:06 PM 4/26/00 -0400, you wrote:
> > >I did my demonstration of a Tesla coil discharging into a metal rod in
> my
> > hand
> > >with a flourescent buld in the other hand once for a high school and
> didn't
> > >realize that the floor was cement under the tile.  Talk about a
> hotfoot, even
>
> I believe the silica existent at the sand attracts water, even from the
> air, so it should be also one of the reasons why cement is always colder
> than air and somehow a thermal conductor.
> Wagner.

>From: Ken Webster <KenEraseME.....WEBSTER.ORG>
>Reply-To: pic microcontroller discussion list <EraseMEPICLISTMITVMA.MIT.EDU>
>To: RemoveMEPICLISTEraseMEEraseMEMITVMA.MIT.EDU
>Subject: Re: Fire in the Hole!!!
>Date: Wed, 26 Apr 2000 02:10:29 -0600
>
>That kinda reminds me of a time several years ago I got ahold of a big
>grab-bag of assorted tantalum capacitors.  They were supposedly all rated
>for 20V or higher and had a longer lead to denote the positive side but
>were
>otherwise unmarked.
>
>I happened to have a 12V lead-acid battery just sitting on my desk so I
>quickly whipped up a little test circuit on a protoboard with a load
>resistor and voltmeter so I could get a rough idea what size each capacitor
>was by counting how many seconds it took to discharge to about 9V.
>
>So I went about sorting the capacitors by briefly touching them to the 12V
>battery and then plunking them into the protoboard and counting the
>discharge time.
>
>Ok .. how many of you out there couldn't see this comming? ... After
>measuring a coupple dozen capacitors I was getting a bit bored and tired
>and
>spaced out a bit and touched one of the capacitors to the battery backwards
>...  -- POP! -- ... "What the?! ... Doh! .. Oh, well .. plenty more where
>that one came from, no big deal.  Cool!  The whole thing blew up!"  (all I
>had left was a coupple of leads barely held together by a bit of epoxy but
>the body of the capacitor was nowhere to be seen).
>
>I was just about to go back to sorting capacitors when I noticed a fire
>break out on the other end of my desk ... it seems that the little
>cylindrical core from inside the capacitor was quite hot and had landed on
>a
>stack of papers!  I'm just lucky that that thing flew over there instead of
>into my eye!
>
>Ken
>
>
> >Experiences should be shared.
> >
> >Just playing with a new small calibrator board over my computer desk,
> >taking measurements of the parts, board, LCD, battery etc, to draw the
> >physical position of the parts into the new instrument case...
> >disconnected the 4 x AA NiCad cells + wire from the circuit, just in
> >case, you know... taking measurements from the small 2x16 LCD unit,
> >entering it at the CorelDraw, here and there, then suddenly by the very
> >corner of the eye I saw something strange like moving at the side,
> >physically close to where was the disassembled unit.
> >
> >I am getting old, so somehow weak eye sometimes "see" things that
> >doesn't exist, you know, tired eyes and so on. But this thing was much
> >more than an eye tricky ilusion, blinked eyes to "clean" it better, the
> >strange thing was there, like moving as a ghost... then probably half
> >second after I noticed it by the first time, I turn my eyes back to the
> >board, LCD and things, my goodness, everything was on fire, fast one,
> >multiwire cable connecting LCD to the Board was transformed into a
> >bright lamp, papers below the cable was burning fast, in less than 2
> >seconds I got a real fire on my desk, lots of smoke... then I thought
> >laughing "Do I call 911 or just disconnect the damn battery + wire from
> >the LCD metal face? ... people at home asked me "What a hell is
> >happening? It finally worked? hehe.
> >
> >The real accident in the last 8 years. Cable is complete wasted, Checked
> >circuit board and LCD board intact... power it on... working.
> >
> >Thinking seriously to use a fuse in series with ALL my NiCad batteries
> >from now on... they are quite dangerously low impedance units.
> >
> >The experience was interesting, can you imagine it just happening with
> >nobody around?  Fire in the Hole!!!.
> >
> >Wagner.

>
> Thanks for the reminder, Bill.
>
> If you are traveling on a plane, PLEASE don't put rechargeable cells in your
> checked luggage.  Keep them with you as carry-on, even though they are usually
> heavy and a nuisance to carry.  It's a lot easier to extinguish a fire in the
> cabin than it is in the cargo bay.
>
> Remember ValuJet.
>
> Andy

> Oh my, I just thought something nasty could happened last week. I went
> to Houston to demonstrate a prototype... the same I put fire on my desk
> days ago (shame)..., took it with me, since I was carrying just a hand
> bag with clothes and survivel for a couple of days.  Taking the flight
> back to Orlando, the customer gave me some samples and other stuff, so
> my hand bag got a little bit bigger, but perfectly fit to take onboard.
> The flight was really crowded for the stop at New Orleans (well, I can
> understand), so they were filtering hand bags at the airplane door to
> check it in to the cargo bay, and they took mine too. I thought for a
> moment, nothing breakable, just a notebook inside but protected...
> prototype is on the top of the hand bag, easy, let it go.  Arrived at
> Orlando with the prototype front panel broke (plastic case), pressed
> deep into the electronics... the power-on switch was lose with terminals
> less than 1/8" from touching the electronics, but for a strike of luck
> the same NiCad pack didn't short circuit. There was a (flammable) nice
> after-shave lotion plastic bottle near the prototype. Can you imagine
> what could happens at the cargo bay?  I really need to take extra care
> with NiCads...  And airport security sniff all our luggage for
> explosives... perhaps they should include NiCad chemical signature at
> the tracer machine...
>
> Andrew Kunz wrote:
> >
> > Thanks for the reminder, Bill.
> >
> > If you are traveling on a plane, PLEASE don't put rechargeable cells in your
> > checked luggage.  Keep them with you as carry-on, even though they are usually
> > heavy and a nuisance to carry.  It's a lot easier to extinguish a fire in the
> > cabin than it is in the cargo bay.
> >
> > Remember ValuJet.
> >
> > Andy
>

> Why should cement be conductive? Because it holds water well?
>
> Sean
>
> At 11:06 PM 4/26/00 -0400, you wrote:
> >I did my demonstration of a Tesla coil discharging into a metal rod in my
> hand
> >with a flourescent buld in the other hand once for a high school and didn't
> >realize that the floor was cement under the tile.  Talk about a hotfoot, even
>
> |
> | Sean Breheny
> | Amateur Radio Callsign: KA3YXM
> | Electrical Engineering Student
> \--------------=----------------
> Save lives, please look at http://www.all.org
> Personal page: http://www.people.cornell.edu/pages/shb7
> RemoveMEshb7KILLspamcornell.edu ICQ #: 3329174

>
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> Hash: SHA1
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>
> >> And this is nowhere better illustrated than this List: there
> >> are no women here. How many programmers are women - 5% at
> >> most I would guess.
>
> Of the programmers I've met, I'd agree that it's about 5%, and they also
> seem to be the most competent 5%.
> I have sort of a list of people I'd like to work for, and several entries
> are female programmers I have known.
> Not a sexual thing, just that they were great to work with, and very
> competent.
>
> - --
> Are you an ISP?  Tired of spam?
> http://www.spamwhack.com  A pre-emptive strike against spam!
>
> Where's Dave? http://www.findu.com/cgi-bin/find.cgi?kc6ete-9
>
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