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"It's not the volts that kill, you its the amps"

Discussion in 'General Electronics Chat' started by bryan, Nov 3, 2012.

  1. bryan

    bryan Member

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  2. WTP Pepper

    WTP Pepper Active Member

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    What kills you is the energy dissipated in the body over a period of time (however short that may be).

    It's the Volts that Jolts, and the mills that kills.

    30mA across the heart for a few seconds is enough to stop it permantely. However that value is derived.
     
  3. Vizier87

    Vizier87 Active Member

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    I have been questioning that statement for quite some time when I was curiously playing around with an electronic fly swatter.... and touched the mesh on my elbow. Got a heck of a shock. :D
     
  4. dave

    Dave New Member

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  5. ()blivion

    ()blivion Active Member

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    Good video. Mostly accurate from what I could tell. There were some minor inaccuracy's, nothing worth bothering the author with.

    5:37 - Shouldn't ignore the resistance. If it will be shocking a person then it will be going through body resistance. Still dangerous enough to call "fatal".
    6:57 - "Tazer" is a brand name, not a circuit. The politically correct term for the high voltage self defense weapon is "stun gun".
    7:00 - Stun guns do not have a resistor in the high voltage side as is claimed. The energy is limited by limiting the watts entering the secondary of the transformer.

    Some important things I would have not left out of any electricity safety video.

    (1) A healthy person can almost always be resuscitated from an electric shock with the proper application of CPR.
    (2) There is a big difference between ventricular fibrillation and electrically induced tissue damage. The latter does not have a demographic.
    (3) Electricity can easily kill the hell out of you without going near your heart. Read the above again.
    (4) Many things can decrease the power needed to cause a fatality. Such as standing in an electrolyte, wearing jewelry, sweating (this was mentioned).

    Of all the issues I saw with the video. I think the only important inaccuracy was mentioning heart problems putting you at risk. This haphazardly creates the possibility for the misconception that you are safe if you do not have such issues, which simply isn't true. Anyone is at risk for electrocution with the right levels of energy. The MOST at risk individuals are those with known or unknown heart issues. That should obviously mean that a healthy person shouldn't run around fixing power lines in the rain with an aluminum ladder. But one often does have to make these things crystal clear when creating a health and safety video of any sort.
     
    Last edited: Nov 6, 2012
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  6. Dean Huster

    Dean Huster Well-Known Member

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    Don't forget that Thomas Edison, who was always pushing for his DC power distribution systems, declared that DC is relatively safe and that AC kills, which is why they use AC for the executioner's electric chair.
     
  7. ()blivion

    ()blivion Active Member

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    Yup, which is pretty much a load of crap. The safety differences are marginal at best.
     
  8. bryan

    bryan Member

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    Saw a DIY show about the hazards of electric fences, proper ones are designed to slowly cycle/regualte so that if one gets shocked the next cycle gives them a chance to let go of the wire. Not sure how accurate it was, but made sense.

    Not sure how true this is but have read that 120v will tend to cause the electrocuted person to grasp the wire, whereas 240v tends to throw the user off the wire. Suppose it's a myth, and I don't plan on testing it.:D
     
    Last edited: Nov 4, 2012
  9. MrAl

    MrAl Well-Known Member Most Helpful Member

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    Hi,

    If you cook meat it is no longer meat but lacks much of the moisture. If you zap skin cells or other body cells they either cook or just die as their chemical structure changes even a little bit. Power (volts times amps) causes cooking but also current causes neurological disruption in communication and that can stop the heart from getting the proper signals from the brain. If the cells are not fried all may be restored if the current is removed but it depends how much has been damaged by cooking.
    So it's really both voltage and current but you can specify just the current and assume that if the current is there then the voltage must have already been there too in order to get the current flowing.
    Supposedly high voltage that does not penetrate the skin too deeply doesnt kill because it doesnt harm any cells.
     
    Last edited: Nov 4, 2012
  10. Reloadron

    Reloadron Well-Known Member Most Helpful Member

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    When I was a kid I built one of these and cooked hot dogs using 120 VAC mains. :)

    Yes, while the current kills it takes enough voltage to have the required current flow.

    Ron
     
  11. bryan

    bryan Member

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    I remember my mom buying a hot dog cooker based on the same principle back in the 70's. Never seen them since. The hot dogs tasted awful, smelled and tasted like ozone!!
     
  12. Reloadron

    Reloadron Well-Known Member Most Helpful Member

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    Mine were good hot dogs. :) Believe me being born and raised in NYC I know what a good hot dog is. Electrically cooking them shouldn't effect the flavor.

    If you read that old story I linked to, they do mention not using galvanized nails. Hot dogs are loaded with salt making them nice and conductive (low resistance). The hot dogs cook much as we cook when the voltage is high enough to get plenty of current flow.

    Ron
     
  13. KeepItSimpleStupid

    KeepItSimpleStupid Well-Known Member Most Helpful Member

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  14. bryan

    bryan Member

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    Maybe the reference to smelling and tasting like ozone was incorrect, perhaps more of a metallic taste, definitively not as good as boiled or pan fried hot dogs:D
     
  15. KeepItSimpleStupid

    KeepItSimpleStupid Well-Known Member Most Helpful Member

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    I'll go with metallic taste.
     
    Last edited: Nov 4, 2012
  16. Mr RB

    Mr RB Well-Known Member

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    Do you know what happens when you run electric current through moist salts? :eek:

    And many of the salts used on "manufactured meat" are ALREADY pretty toxic, like nitrates etc (which is why they add them as preservative, toxic enough to kill germs, not quite toxic enough to kill you). ;)
     
  17. Vizier87

    Vizier87 Active Member

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    How did it taste? :p
     
  18. jpanhalt

    jpanhalt Well-Known Member Most Helpful Member

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    Although nitrates can have some antimicrobial activity and apparently are necessary to prevent spore germination of the organism that causes botulism (http://en.wikipedia.org/wiki/Curing_(food_preservation), a major main reason for nitrates, perhaps the main reason in most cases, is to preserve redness and appeal of meats.

    Many microorganisms not only are able to tolerate relatively high nitrate concentrations but are able to use it for a source of energy. That is, instead of using oxygen as the terminal electron acceptor in respiration, they are able to use nitrate and reduce it to nitrite. According to Wikipedia, the maximum nitrate concentration in meat is limited to 200ppm (0.2g/liter); anaerobes and facultative anaerobes such as the Enterobacteriaceae grow well in 2000 ppm. Among that latter family of bacteria are the enteric pathogens E. coli O157:H7 and related strains, Shigella, and Salmonella.

    John
     
    Last edited: Nov 5, 2012
  19. Mr RB

    Mr RB Well-Known Member

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    Thanks for the info I did not know that! I still don't like to eat nitrates, you eat a few sausages at a barbie and always get the worst headaches.

    Nobody mentioned about the toxicity of running high currents through moist salty foods?
     
  20. jpanhalt

    jpanhalt Well-Known Member Most Helpful Member

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    Maybe this funny newspaper clip is appropriate here:
    View attachment 68476

    The point to be made is that fresh meat, particularly ground meat, needs to be cooked. There are never enough antimicrobials in it to make it microbiologically safe. Radiation (e.g., gamma) can be used to sterilize it, but such meat is rarely available.

    John
     
  21. bryan

    bryan Member

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    Too funny, every time I hear Meat Head, think of the old 70's show All in the Family. Anyone over 40 would know what I mean.
     

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