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Kindling for the Fire

Discussion in 'Electronic Repair' started by Watson A.Name - Watt Sun, Sep 11, 2003.

  1. I remember, when I was a kid, we had a veggy tray from an old fridge
    that we used for draining the oil from the engine when we changed oil.
    One time we had some oil in it out in the back yard and I decided to
    see if it would burn, so I wadded up a sheet of newspaper and lit it,
    and tossed it in the pan. Well nothing much happened at first, the
    paper just acted as a candle wick, and kept burning. But the oil
    started getting hotter and finally started burning too. The flames
    started getting bigger, so I decided it was time to put the fire out.
    So I turned the water hose on the pan. WHOA-HO-HO! Big mistake! The
    flames shot up ten or fifteen feet! What a conflagration! The water
    hit the boiling oil and turned to steam, and that was like blowing air
    on the oil. Nice way to get scalded and burned. So I learned a
    lesson: never put water on burning oil. Later I learned that it
    doesn't work with magnesium, too. :p

    So here's some kindling for the fire.
    http://www.rfcafe.com/references/electrical/electrocution.htm
    I like starting a fire here once in a while, but it usually turns into
    something of a totally different topic, and the bozos don't have the
    courtesy to change the subject line so it just keeps on burning, and
    burning...


    --
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    ###Got a Question about ELECTRONICS? Check HERE First:###
    http://users.pandora.be/educypedia/electronics/databank.htm
    My email address is whitelisted. *All* email sent to it
    goes directly to the trash unless you add NOSPAM in the
    Subject: line with other stuff. alondra101 <at> hotmail.com
    Don't be ripped off by the big book dealers. Go to the URL
    that will give you a choice and save you money(up to half).
    http://www.everybookstore.com You'll be glad you did!
    Just when you thought you had all this figured out, the gov't
    changed it: http://physics.nist.gov/cuu/Units/binary.html
    @@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@@[email protected]@[email protected]@@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@@
     
  2. Congrats, Win - you've thrown the first stick on the fire. Thanks.


    --
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    ###Got a Question about ELECTRONICS? Check HERE First:###
    http://users.pandora.be/educypedia/electronics/databank.htm
    My email address is whitelisted. *All* email sent to it
    goes directly to the trash unless you add NOSPAM in the
    Subject: line with other stuff. alondra101 <at> hotmail.com
    Don't be ripped off by the big book dealers. Go to the URL
    that will give you a choice and save you money(up to half).
    http://www.everybookstore.com You'll be glad you did!
    Just when you thought you had all this figured out, the gov't
    changed it: http://physics.nist.gov/cuu/Units/binary.html
    @@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@@[email protected]@[email protected]@@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@@
     
  3. Glen Walpert

    Glen Walpert Guest

    And what do they think the difference is between "Ventricular
    Fibrillation" at 90 mA and "Death" at 100 mA? Other than about 5
    minutes, except under the most unusual circumstances?

    Possibly more accurate info at
    http://www.osha.gov/SLTC/etools/construction/electrical_incidents/eleccurrent.html

    http://www.agc-ca.org/services/safety/Sb97-2.htm

    http://cpmcnet.columbia.edu/texts/guide/hmg13_0006.html

    Low voltage electrocution is most often caused by Ventricular
    Fibrillation, described at:

    http://sprojects.mmi.mcgill.ca/cardiophysio/venticularfibrillation.htm

    http://www.emedicine.com/emerg/topic633.htm

    For the description of the unusual circumstances where Ventricular
    Fibrillation may not be fatal:

    http://www.utilitysafety.com/archive/articles/jump_start_a_heart.htm

    Unfortunately I can't now seem to find any references which describe
    the exact electrical mechanism by which Venticular Fibrillation (VF)
    occurs, although it is well understood. Deliberatly induced VF is
    used to temporarily stop the heart for surgery, by applying a short,
    low current pulse to the nerve which fires the heart (crudely put)
    durung the "reset" or "succeptable" part of its cycle - essentially
    preventing the recharge of the ion powered synapse, so that it cannot
    fire, and without firing, it cannot recharge. I have read that it is
    not actually current which is critical, but dI/dt during the reset
    period, and since the dI/dt on initial contact can be much greater
    than during the subsequent sineusoidal current, initial contact at the
    right polarity and timing of the heartbeat can cause death at currents
    much lower than those that reliably cause death (per the standard
    charts). Note that GFI breakers can take up to 1/10 sec to trip, and
    provide no protection from initial contact electrocution!

    Furthermore, individual succeptablilty to VF varies widely, and there
    are plenty of documented cases of death caused by only a few
    milliamps.

    Bottom line as I see it is that contact with line voltage is a lot
    like Russian Roulet with 1 bullet and a few hundred empty chambers.
    Why risk it?

    Regards,
    Glen
     
  4. Hi!

    Fire, huh?

    Nothing teaches you respect like fire can. Well, maybe electricity, but fire
    produces a much better visual example...and FAIK most folks are visual
    learners.

    Two incidents come to mind that taught me a fair bit of respect for fire.
    The first was my (admittedly VERY stupid -- Do NOT try this at home!)
    spraying WD40 into a bottle I was using to hold spent matches after trying
    to light a grill. Just as a point of curiousity, I grabbed a can of WD40 and
    for no really good reason, I sprayed it into the bottle. FOOM! That made a
    nice little channel of fire...

    The second involved my conducting strange experiments on a bottled water
    bottle. I put a little (about a teaspoon) of white fuel into the bottle and
    tried to light it from a distance with an old pilot lighting stick I have
    for such things. It took, and I decided to put it out by stomping it flat.
    Bad idea. It went FOOM for a brief moment and then burned out.

    I've never had any injuries and I don't plan to do anything foolish enough
    to get any. It is a very seldom occurence that I burn anything. Every now
    and then I feel that setting some hopelessly beyond repair or just plain
    worn out equipment on fire can be quite fun, if done properly and SAFELY in
    an area where nothing can get out of control and a fire extinguisher is kept
    handy.

    As for the thing on lethal amounts of electricity, I just don't think I buy
    into it. I know an elderly electrician whose quick and dirty way to find a
    110 circuit from 220 circuits (or the other way around) was to simply touch
    them and say "this one tingles more". I would never do that myself, but this
    guy isn't young and he is certainly still alive...and probably after having
    done this very often!

    William
     
  5. True - for a better effect mix in some Turpentine followed by a generous
    dose of fuming Nitric Acid instead;

    Notes:

    You do not have to ignite the Oil beforehand; you will want to devise a way
    to pour the nitric acid from a safe distance of about 100 m for 5 liters of
    oil and you probably want to do this in a place where there are no flammable
    items and spectators around.
     
  6. Well, so far I've managed to dodge the bullet, after all the times
    I've been shocked. Perhaps other people haven't been shocked as many
    times as those of us who deal with electricity/electronics, but they
    for the most part have dodged the bullet too.

    But then most of life is like that. It's only a matter of time before
    something you do gets you. Like driving, it's only a matter of time
    before someone gets into an accident. Hopefully not fatal. But then
    more people die in auto accidents than any other accident. So does
    that stop us from driving? No.
    --
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    ###Got a Question about ELECTRONICS? Check HERE First:###
    http://users.pandora.be/educypedia/electronics/databank.htm
    My email address is whitelisted. *All* email sent to it
    goes directly to the trash unless you add NOSPAM in the
    Subject: line with other stuff. alondra101 <at> hotmail.com
    Don't be ripped off by the big book dealers. Go to the URL
    that will give you a choice and save you money(up to half).
    http://www.everybookstore.com You'll be glad you did!
    Just when you thought you had all this figured out, the gov't
    changed it: http://physics.nist.gov/cuu/Units/binary.html
    @@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@@[email protected]@[email protected]@@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@@
     
  7. James Meyer

    James Meyer Guest

    Almost all auto "accidents" are not really accidental. They usually
    result from "applied stupidity".

    I think electrical shocks are similar.

    Jim
     
  8. Tom was working on a TV chassis which was sitting on its side, power
    applied, cable attached. Tom bumped the cable, and, before Tom's
    magnificent dive to the Sencore isolation unit's power switch, the
    chassis bottom made contact with Tom's left forearm. Tom was left with
    dozens of burns from the various voltages present. :)

    This didn't even compare, though, with the time that Tom tongue-tested
    a cellular telephone PS, 10.6VDC, 850 mA. OUCH!!

    Tom
     
  9. This looks like an Urban Legend to me. According to the manual for
    Simpson 260-6P, the most the current can be with the probe tips
    shorted is 75 uA. Below is an excerpt from that manual:
    (use Courier font.)

    From Simpson 260-6P Technical Data, Table 1-1 Page 1-8

    8. Ohmmeter Circuit Effects
    Range: R X 1 R X 100 R X 10,000

    Nominal Open
    Circuit Voltages: 1.5V 1.5V 9.0V

    Nominal Short
    Circuit Current: 125mA 1.25mA 75 uA


    Indeed, the low ohms range can supply 125 mA, but at 1.5V it's
    doubtful that that could have harmed him even with the probe tips in
    his skin. Also, there is no warning anywhere in the manual of harmful
    effects such as the one described. And as far as I know, there has
    never been a documented case of this accident happenening in the
    civilian world (this might reflect more on the U.S. Navy and the
    oxymoron 'military intelligence'). And there were millions of Simpson
    meters out there being used - they were the standard VOM for decades.
    So I believe there has been some serious distortion of the truth
    somewhere.

    I got these .GIF pics of the whole manual including the schematic from
    somewhere on the web. It might have been navyrelics.com or some test
    equipment schematic website, in case anyone wants to verify this.


    [snip]

    --
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    ###Got a Question about ELECTRONICS? Check HERE First:###
    http://users.pandora.be/educypedia/electronics/databank.htm
    My email address is whitelisted. *All* email sent to it
    goes directly to the trash unless you add NOSPAM in the
    Subject: line with other stuff. alondra101 <at> hotmail.com
    Don't be ripped off by the big book dealers. Go to the URL
    that will give you a choice and save you money(up to half).
    http://www.everybookstore.com You'll be glad you did!
    Just when you thought you had all this figured out, the gov't
    changed it: http://physics.nist.gov/cuu/Units/binary.html
    @@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@@[email protected]@[email protected]@@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@@
     
  10. When I was a kid, we used to pull stunts like this by putting the
    nasty stuff in a glass bottle and shooting it from a distance with a
    pellet gun or .22 caliber rifle. Man, that HNO3 sure burns your mucus
    membranes. Makes an ugly brown cloud. This chemistry fanatic I knew
    was into that kind of stuff. Most of my other friends were content to
    just play with gunpowder. :)

    I think my favorite liquid dispensing container was a spray can with a
    tire valve soldered on the side. I could fill it up with the juice,
    and prssurize it to a hundred pounds with a tire pump. Worked great
    with flammable liquids, spit out a stream several yards long.

    Since my dad painted, he had some of that stuff in a can. About the
    only thing that turpentine seemed useful for was for putting on a
    cat's rear end. They didn't like that very much. :))

    --
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    ###Got a Question about ELECTRONICS? Check HERE First:###
    http://users.pandora.be/educypedia/electronics/databank.htm
    My email address is whitelisted. *All* email sent to it
    goes directly to the trash unless you add NOSPAM in the
    Subject: line with other stuff. alondra101 <at> hotmail.com
    Don't be ripped off by the big book dealers. Go to the URL
    that will give you a choice and save you money(up to half).
    http://www.everybookstore.com You'll be glad you did!
    Just when you thought you had all this figured out, the gov't
    changed it: http://physics.nist.gov/cuu/Units/binary.html
    @@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@@[email protected]@[email protected]@@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@@
     
  11. In this case, I used the term accident to differentiate between that
    cause of death and death by natural causes, such as cancer. So you
    could put quotes around that term.

    --
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    ###Got a Question about ELECTRONICS? Check HERE First:###
    http://users.pandora.be/educypedia/electronics/databank.htm
    My email address is whitelisted. *All* email sent to it
    goes directly to the trash unless you add NOSPAM in the
    Subject: line with other stuff. alondra101 <at> hotmail.com
    Don't be ripped off by the big book dealers. Go to the URL
    that will give you a choice and save you money(up to half).
    http://www.everybookstore.com You'll be glad you did!
    Just when you thought you had all this figured out, the gov't
    changed it: http://physics.nist.gov/cuu/Units/binary.html
    @@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@@[email protected]@[email protected]@@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@@
     
  12. Fortunately they were only burns.
    I've tongue tested (as have probably just about everyone else) a fresh
    9V battery, and your battery isn't that much more. Should have given
    you a bit of a twinge... :)

    --
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    ###Got a Question about ELECTRONICS? Check HERE First:###
    http://users.pandora.be/educypedia/electronics/databank.htm
    My email address is whitelisted. *All* email sent to it
    goes directly to the trash unless you add NOSPAM in the
    Subject: line with other stuff. alondra101 <at> hotmail.com
    Don't be ripped off by the big book dealers. Go to the URL
    that will give you a choice and save you money(up to half).
    http://www.everybookstore.com You'll be glad you did!
    Just when you thought you had all this figured out, the gov't
    changed it: http://physics.nist.gov/cuu/Units/binary.html
    @@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@@[email protected]@[email protected]@@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@[email protected]@@
     
  13. James Meyer

    James Meyer Guest

    When I were a lad, I used to make chlorine gas and put a cotton ball
    with turpentine on it down into the green chlorine gas. It started "burning"
    almost instantly. One of the byproducts was hydrochloric acid.

    Jim "Still amazed that I survived." Meyer
     
  14. The following can be fun too: Fill a vessel up with salt water. throw
    in two carbon rods connected to a car battery charger.
    Run it a while till most of the chlorine has gone out.
    Power off, put on a lid, hide behind a wall, power on and run the
    generated gass into a SMALL baloon. Power off when 5" diameter.
    Use a light plastic lid that will pop off and not hurt anyone if the
    gas in the vessel ignites.

    Then hold the baloon at arms length, close your eyes and take a match
    to it. Do it with your hair wet, in wet smim trunks next to a swimming
    pool so you can jump in if you catch fire. We had great fun with this
    as kids. It is not unbearably loud but generates an incredible bang
    and you feel a heat pulse similar to what you get when you set off a
    large photoflash right against your skin.
     
  15. I recommend wearing ear plugs.
     
  16. OK Watson, I give up. What effect does it have on the cat??
     
  17. I suspect the internal resistance of the battery limits what can flow
    through your nice, wet tongue. I don't remember the short-circuit current
    of a typical 9V battery, but it seems to me the last time I tested one
    it was in the tens of milliamps.
     
  18. Zak

    Zak Guest

    I understand such a balloon may ignote if you fire a photoflash at it.


    Thomas
     
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