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Magnetic Field Reduction

Discussion in 'Gen 2 Prius Accessories & Modifications' started by Ellie, Jan 29, 2008.

  1. jayman

    jayman Senior Member

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    Multipath can really suck too
     
  2. qbee42

    qbee42 My other car is a boat

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    I hate multipath. That's why those little wifi access points have two antennas. The two antennas allow two different locations to pick up the same signal. If you have multipath, one will be better than the other. The multi-antenna idea is called spacial diversity.

    Tom
     
  3. jayman

    jayman Senior Member

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    +1, actually it's called "spatial diversity."

    The White ALICE system used a combination of frequency and spatial diversity to make tropospheric scatter - or troposcatter - work. Similar techniques were used by the Dew Line, Pinetree Line and Mid Canada Line for early warning radar

    I have some photos of the troposcatter used at DEW sites in Greenland
     

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  4. EZW1

    EZW1 Active Member

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    First of all, understand that every piece of electronic equipment sold to the consumer (at least in the USA) must meet EM certification. If it doesn't it will either horribly cause interference to other electronic devices, or be susceptable to stray EM fields. Either scenario is very displeasing to the consumer. So, that said, I wouldn't worry much about your EM emissions. But, if you must worry, then go after the largest EM source in any vehicle: the Alternator. The second largest source is the ignition coils. How do you clean them up? Well, the best and most effective is to shield them somehow. The easiest shield is aluminum foil. As with any shield, care must be taken to ground the shield to the chassis. Othersise, the shield will have little effect.

    So, I wouldn't worry..
     
  5. FL_Prius_Driver

    FL_Prius_Driver Senior Member

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    Dang. When I went to do this in my Prius......
     
  6. Welshdog

    Welshdog Member

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    I don't think anyone can say with any certainty that EMF or RF exposure is completely harmless or has no effect. We just don't really know for sure and may not ever know. Also someone mentioned earlier that if it was harmful the military would not let soldiers be exposed to RF and the like from radio transmitters or aircraft carrier com and radar gear. Really? Since when does the military care much at all about occupational safety? My late father in law would argue with you on that one as he was ordered to "volunteer" for pressure experiments while in the navy. These "volunteer" experiments gave him hearing damage and vertigo. And when he sought medical attention it was denied. I'm sure you can ask many thousands of military folks about their exposure to hazards in their workplace and you would get an earful (Agent Orange). I thought everyone had gotten past the idea that "If it wasn't safe the government wouldn't allow it". Gasoline is proof that argument doesn't hold water - it is the most toxic, carcinogenic and explosive material we expose ourselves to on a regular basis. If you handle it in a laboratory you do it in a fume hood and are wearing protective gear. The government's solution is to put some wimpy stickers on the gas pumps warning people of the hazards. Yeah right, they're looking out for our well being. That is one additional benefit of owning a Prius - greatly reduced exposure to gasoline fumes.

    Anyway, if you are curious to see some interesting ways to control EM radiation check this site. They sell some really amazing woven metal fabrics that can be used to create Faraday like environments. I remember reading an old study (probably Swedish) that found people who slept in EM free rooms (Faraday shielded) had better quality sleep and deeper REM cycles. Proof of anything? Who knows, but interesting nonetheless.

    Electromagnetic Field Shielding Fabrics
     
  7. donee

    donee New Member

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    Hi EZW,

    Of course the Prius does not have an alternator. And the motors are already inside a cast aluminum casing, with only small holes for gas pressure equalization. The inverter circuit is inside a large casting with a clam-shell shield on top.

    This thread is mostly about the magnetic fields. The RF fields are very small as to not cause any health issue. The magnetic fields can go right through aluminum however, but not the steel body structure.

    To reiterate, to get the same exposure to the magnetic fields that the Prius emits in the passenger compartment - go out into a middle of a mid-latitude rural field, far from any electrical equipment, and spin around real fast until you get dizzy. The static magnetic field of the earth is stronger than what is in the Prius, and by spining you will get sufficient dB/dT to induce similar currents in your body.
     
  8. qbee42

    qbee42 My other car is a boat

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    Spacial and spatial are the same thing. Spacial is a variant spelling and listed as such, as in color and colour. That said, spatial is the original spelling and the one I would normally use if I had any aptitude for spelling.

    Tom
     
  9. qbee42

    qbee42 My other car is a boat

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    True, but we can say with certainty that any effect is small, otherwise the world would be full of stunning examples of damage from EMF and RF exposure. It's all around us, and impossible to avoid. We have been our own guinea pigs for the past half century.

    Tom
     
  10. jayman

    jayman Senior Member

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    Tom

    By now you should know what a stickler I am for things being done the right way.

    BTW if you look up "stickler" in the dictionary, there is a photo of me, and you are also redirected to "donkey"

    jay
     
  11. jayman

    jayman Senior Member

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    No, I'm not saying that, and I don't think anybody can claim "zero" risk as there is no such thing. At a certain point you have to consider things like TLV's, and consider that even TLV's have historically been revised dramatically downwards

    Agent Orange is an interesting topic. It was actually a *very* effective broad herbicide and defoliant. It used approx 45% 2,4,5 trichlorophenoxyacetic acid, a synthetic auxin and defoliant, 45% 2,4 dichlorophenoxyacetic acid, a synthetic auxin and herbicide, about 5% kerosene, and 5% emulsifiers and other trace chemicals

    The reason Agent Orange had toxic side effects had to do with the 2,4,5 T. When you make 2,4,5 T it's crucial to achieve strict batch temp control. If you don't, and temps exceed a certain limit, you end up with large amount of 2,3,7,8 tetrachlorodibenzo-penta-dioxin, usually listed 2,3,7,8 T or just "dioxin."

    Apparently, most of the Agent Orange used during the Vietnam war was made in the Czech republic. No fussy EPA requirements there.

    I should warn you that all of us in North America were exposed to Agent Orange. It was widely used by utility companies, pipeline operators, county and municipal agencies, etc. It was sold by Dow Chemical as Esteron Brush Killer.

    As far as the Cambodian birth defects even now going on, one has to wonder if it is due to residual 2,3,7,8 T activity or chronic malnutrition, especially iron defecincies
     
  12. bwilson4web

    bwilson4web BMW i3 and Model 3

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    [​IMG]
    In 1879, Edison invented the electric light and soon the world adopted electricity and their resultant electromagnetic fields. Notice what happened to human life expectancy at the same time.

    Then in 1895, the Niagara Falls power plant opened up and AC became all the rage. Once again, average human lifetimes increased. Other than war and the flu pandemic, average human lifetimes have increased along with more and more RF and electromagnetic fields.

    The data suggests a positive correlation of RF-electromagnetic fields and longer human lifetime. So given a choice, I prefer what seems to extend human life. However, you are welcome to seek EMI isolation.
    :deadhorse:

    My first recommendation is to seek the maximum distance from computers, keyboard and screens. Start with a grounded, metal screen for the computer, monitor, keyboard and mouse. There are metalized plastic and glass covers that you can use too. Don't forget to use a shielded power cord ... and your house wiring. But this may not be enough.

    There are a few places on earth almost free of all EMI:
    [​IMG]
    Yes, get thee to a salt mine, my Luddite friend. Don't forget to turn off the lights.

    Bob Wilson
     
  13. qbee42

    qbee42 My other car is a boat

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    I'm a stickler too - a stickler with no aptitude for spelling. It's a bad combination. I drive myself nuts with spell-check and dictionaries. Unfortunately there are words like this one, where a clueless stickler like myself can misspell it and end up with an acceptable alternative, if not the preferred one. Spell check offers no help in this situation.

    Tom
     
  14. jayman

    jayman Senior Member

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    Tom

    Meh!

    After I get 5-7 drinks into you, I will *guarantee* you won't care.

    :evil:

    Hmmmm ... this could get interesting

    :dizzy:

    :faint:

    ROAD TRIP!!

    jay
     
  15. dwreed3rd

    dwreed3rd New Member

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    Bob, This does not reference EMF. I just wanted to make a side comment regarding life expectancies. Sadly we are at the first time in history that acturies are predicting that, in American, our childred will have a lower life exprctancy than we do.

    Life Expectancy

    What is the average life expectancy of Americans? For a long time it has been the low seventies for men and upper seventies for women. So it comes as a shock to learn that the average life expectancy for Americans has dropped to 69.3 years, according to the America's Health Rankings report, issued at the American Public Health Association's annual meeting. This figure is exceeded by 28 other countries, including Britain, France and Germany and is about five years less than the life expectancy in Japan. According to Dr. Reed Tuckson, this dismal number reflects increasing obesity, fewer people quitting smoking (although only 20.8 percent of Americans smoke today, down from almost one-third in 1990), and increasing numbers of people without health insurance. Officials made no mention of the increasing consumption of processed foods containing refined sweeteners, processed vegetable oils and toxic additives, and certainly did not allow even a whisper about the almost complete absence of nutrient-dense foods such as organ meats, shellfish and butterfat and eggs from grass-fed animals from the American diet (Reuters, December 13, 2005).
     
  16. FL_Prius_Driver

    FL_Prius_Driver Senior Member

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    I do not expect the tread to continue for a whole lot longer no matter what. Also not covered is the quality of life. If I live to 100 and spend the last 30 in a home is NOT what I want. I'm seeing way too much of that lately. When it comes to various EMF fields, I expect that intensities and exposures will keep increasing till there is some detectible effect.

    (P.S. Bob W.- Where did you get a picture of the work place?)
     
  17. bwilson4web

    bwilson4web BMW i3 and Model 3

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    I had pointed out the two key sources of all Electro Motive Force:

    • 1879 - invention of the light bulb
    • 1895 - Niagra Falls AC power station
    The benefits of electricity and improved communications has directly contributed to our longer lives. In contrast, we have claims that do not stand up to critical scrutiny.

    Now if someone chooses to live free of EMF/EMI fields, that is fine with me. If they want absolute freedom, a deep mine is the best choice, without electricity. Google Images has a wealth of mine photos to choose from and by all means, it is a good place for some.

    Bob Wilson
     
  18. dwreed3rd

    dwreed3rd New Member

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  19. Welshdog

    Welshdog Member

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    The data suggests no such thing. In fact the data suggests nothing. Nice graph, but where is the connection to EMF etc? I personally am not particularly afraid of magnetic radiation - I am merely willing to discuss it without dismissing the concerns as crazy. Shoot I have more electrical and electronic devices in my home than many. I have 4 Tivos and watch TV all night with a Powerbook in my lap. Of course I'm probably sterile and have no children, but that doesn't bother me. I work in a video post production facility and am surrounded by all nature of computers, tape machines, monitors and the like. I am unconcerned. However I am curious and the ideas and techniques of shielding intrigue me - might be useful if someday we discover that there is a hazard that needs to be dealt with.
     
  20. Stev0

    Stev0 Honorary Hong Kong Cavalier

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    I'm more worried about sprinkler rainbows.