Electricity shock's

Discussion in 'Feedback and Suggestions' started by loosewire, Jun 25, 2008.

  1. loosewire

    Thread Starter AAC Fanatic!

    Apr 25, 2008
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    I can remember when my hand got too close a large radio transformer,just thinking about it I can still fell the way It slamed me. Another time I touched the antenna terminal near a fire place,I found my self halfway across the room.I can see work bench and fire place and fell awfull jolt.I got hit by tv high voltage a few time's,but the jolt from the transformerI fell visalize as I post this. Any other experience's you guy,s want to share. LOOSEWIREP.S. My second post on laptop with wi-fi,checking for public wi-fi location's,first option is Border's and Barne's and Noble's,are they global book store's.Dave,at Border's they have platform and stool,If you have the nerve to get upon the stool and patron's lounging on couche's,you can have your say.I tryed it once,about 25 people no one would look me in eye's. Any thing like that any where guy's and girl's.
     
    Last edited: Jun 25, 2008
  2. Bernard

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    Aug 7, 2008
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    Tecktronics published a note on electrical effects on humans; the thing I remember is 50 milli Amps is the crosover point to lethality, with many exceptions.
     
  3. Wendy

    Moderator

    Mar 24, 2008
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    I think the exception is the circuit path. If it crosses your heart that's it, you're done. Just my opinion though.

    I remember seeing a fellow tech (I was the lead tech on the line at the time) touch 90VDC on a old telephone circuit. He froze, the slowly toppled backwards on a very high chair (the kind that lab was using at the time). I'm afraid I didn't make any friends that day, I asked him if he was OK and he affirmed he was, and I broke out laughing. This really pissed him off, guess he was still smarting.
     
  4. Geir

    New Member

    Jul 28, 2008
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    Memo to self:
    Even though the leads coming off the trafo-circuitboard (220V -> 12V) isn't much, there are still paths beneath that hold and lead 220V.
    Conclusion: Don't hold the circuitboard flat in your hand when connecting the power!! The arm feels a bit...numb...afterwards.

    PS! As far as I know, 6mA across the heart is lethal!

    From Wiki:
     
  5. Unregistered

    Guest

    After 20+ years in the industry and teaching in the industry, here is my 2 cents on electric shock.

    0.001A - tingling sensation is felt
    0.01A - Involuntary muscle movment/contraction occurs
    0.1A across the heart - fatal with no medical help

    Current not woltage is the killer. In the U.S. more people are are killed by 120Vac than any other voltage.

    A technician decided he wanted to know the resistance of his blood, so he poked a probe into the finger of one hand (breaking the skin), and then the a finger on his other hand. If you are familar with how an ohmmeter works... well, he recieved a lethal shock through his heart.

    --James
     
  6. thingmaker3

    Retired Moderator

    May 16, 2005
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    James, can you provide a source for this story? I would like to read into it further. Did he put the probes all the way into his flesh and then put the leads in the meter? What size battery was in the meter? How did he manage to manipulate the second probe with the first one stuck in his finger?
     
  7. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
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    Thingmaker3,

    Maybe it's just me this morning, but I find your signature comment particularly applicable to the comment above. Thanks for the smile. John
     
  8. Mark44

    Well-Known Member

    Nov 26, 2007
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    I'm skeptical of this story. It's hard for me to imagine that the current produced by a small 9v battery or a couple of AA cells would prove fatal
     
  9. beenthere

    Retired Moderator

    Apr 20, 2004
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    Ohmmeters do not produce enough voltage to push a fatal current (freezing the heart muscle). Or producing an electrotetanus sufficient to prevent the guy from removing the probes. Sounds like urban legend to me.

    The testing methodology is silly, too.
     
  10. loosewire

    Thread Starter AAC Fanatic!

    Apr 25, 2008
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    Underwriters lab don't suggest a fuse in small battery operated radio's.
    Car radios are fused, so it get down to current protection.
    Fire protection in auto is also a concern.

    p.s. Remember when radio's before transistor,some radio's had large,what
    was called (a) (b) batteries which was large enough to supply some
    current. Maybe some one got there story and wire's crossed.Help me sort this out.
     
    Last edited: Sep 6, 2008
  11. AlexR

    Well-Known Member

    Jan 16, 2008
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    The old Avo7 multimeter used a 22.5 Volt battery on some resistance ranges. That is more than enough voltage to kill someone if you bypass the skin resistance.
     
  12. Mark44

    Well-Known Member

    Nov 26, 2007
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    I've been shocked a few times by 120v AC while changing a light switch in a hot circuit (did it at night, without a flashlight, and wanted the light to see what I was doing). All I felt was an intense tingle for a fraction of a second. So voltage, in and of itself, is not the key, nor is current, in and of itself. I wouldn't dream of working on a 220v circuit that was live, though.

    Granted, I wasn't making a good solid connection, so it's hard to say how much power I was dissipating.
     
  13. loosewire

    Thread Starter AAC Fanatic!

    Apr 25, 2008
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    Mark 44-Think of all the changes in the last 30 years. Plastic has save
    more live than can be estimated.Do you recall the rubber slipper's the
    the nylon rug,plastic cover plates,code grounded curcuit.People don't
    reach from the frig and sink and die any more.Technology has save
    more live and at the same time people are less compelled to be
    concerned about electticty,electronic.The remote is plastic and most
    people would not know it has batteries .
     
  14. Mark44

    Well-Known Member

    Nov 26, 2007
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    Loosewire,
    And your comment relates to this thread -- how?
     
  15. theamber

    Active Member

    Jun 13, 2008
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    Bed time stories...
    I see it this way; the human boby is conductive. Dry skin is not a good conductor this serves as a shield enough voltage will break the skin barrier.
    I haven been shoked docens of times up to 840 VDC that made a hole through my skin and flesh. Also 220 and 120 VAC many times. I am pretty sure you guys had too.
    For the chickens out there... I want to see DEATHS proves of people WORKING on electronic equipment no bedtimes stories.

    Now the real dangers come from high frequencies.
    Inside the human body there are ellectric currents. I have seen also claims that human frequencies vary from a low number of Hz to around 300Hz.
    An
    EEG shows the electrical activity of neurons in the brain.
    An EKG show what the heart is doing. Naturally a real damage depends on frequency and intesity :
    High frequency and intensity may pass through (e.g. X rays).
    Higher frequency 20kH to GHz (radio frequencies) have less and less biological effect (expect from heating if intensity is very high (such as in the microwave oven).
    Very High frequencies (UV, X ray, gamma rays) may be dangerous.
    It has to have certain minimal energy (frequency) to be able to break a chemical bond of the biomolecules.
    High power RF burns those can cause real long term internal damage.
    So using high frequency trasmitters may be worse than working on electronic equipment that includes CRTs TVs.
    The guy that died with the meter probably...Then he was 80 years old and had a pacemaker.



     
  16. loosewire

    Thread Starter AAC Fanatic!

    Apr 25, 2008
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    I thought that you might go back to the electrical box and see if there
    were any insulating factor's that prevented a more deadly shock.
    Like carpet floor or insulated lamp base or other.I started the thread by recounting the shock's that I can still feal now,how I felt the slam from
    touching a radio with a large power transformer. I read your post and respect you very much.Some of my post are hard to read,that just my way,again I respect your work
     
  17. thingmaker3

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    May 16, 2005
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  18. theamber

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    Jun 13, 2008
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    Thanks Thingmaker3, I said electronics not electrical equipment nor natural thunderbolts.
    I was in Spain not long ago in one electrical company... I remember this young guy from Russia... the next day he wasn't there any more but he was working with power lines.

    I want to see probe of someone being killed by for example the monster...a 'CRT TV set' lets say. That may deter me from opening another TV set.
    I think that eating junk food, driving or walking on the streets today has a higher death risk than electrocution from working on ELECTRONIC equipment.

    Check this report:
    http://www.cma.ca/multimedia/staticContent/HTML/N0/l2/cjs/vol-48/issue-4/pdf/pg289.pdf

    United States, estimates of fatalities
    due to electrocution have been
    estimated at 5 per 1 million population
    annually.2–5 Death attributed
    specifically to lightning has varied
    considerably depending on geography,
    with the highest rates of approximately
    1 per 1 million reported
    from southern US.6,7 Male gender
    and an occupation requiring exposure
    to electric current have been
    proposed as risk factors for severe
    electrical injury, although the actual
    risks have been poorly quantified.
     
    Last edited: Sep 20, 2008
  19. thingmaker3

    Retired Moderator

    May 16, 2005
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    There are a plethora of search engines to choose from. May your effort be fruitful.
     
  20. theamber

    Active Member

    Jun 13, 2008
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    No I am not interested, my point is that it is so remotely near to imposible to get killed by working on a TV than it is from stepping on a banana peel. And that should not be a deterrent for any healthy adult with a basic understanding of electricity to work with.
    There are so many real dangers arround us we just need to exercise the logical and propper care... but have this for certain when your time comes noone knows when and where.
    I even used to get shocked with friends for fun everywhere with a taser gun and I am still here.
    Electricity is fun, everyone should respect it but never be horrified by it.
    This I said.
     
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