Technology to absorb Electromagnetic Field energy

Discussion in 'Physics' started by uon, May 1, 2007.

  1. uon

    Thread Starter New Member

    May 1, 2007
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    Apologies if I am ill informed on a lot of the physics side of things.

    Firstly hi to all...:)

    Got recommended to these forums by my gf. My name's Eugene and am an Industrial Design student in Sydney, Australia. Am currently finishing up a project for sustainability through a product. Was wondering...does anyone here have any information on technology that absorbs electromagnetic field energy...ie from other electrical appliances??? Can energy from electromagnetic fields given off by appliances be absorbed and redistributed/re-used???

    I needed to know if the design of my product will be feasible so that I can explain what is going on. I have conceptual ideas, now I need backup information. Thanks in advance.
     
  2. thingmaker3

    Retired Moderator

    May 16, 2005
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    Some hobbyists and university researchers will use graphite crucibles to absorb microwaves for heating metal and/or ore. IIRC it works because of random orientation of the graphite flakes in the clay mix. Ordinary kitchen type microwave ovens are used by the hobbyists. The researchers modify the kitchen type ovens - in one case six magnetrons were ganged together for smelting steel from ore.
     
  3. cumesoftware

    Senior Member

    Apr 27, 2007
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    A case made of iron to protect your circuits will do. Iron is important because it provides magnetic protection also.
     
  4. Dave

    Retired Moderator

    Nov 17, 2003
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    Water, perhaps? (Not a technology, but certain one of the best for EM field absorption).

    Dave
     
  5. Salgat

    Active Member

    Dec 23, 2006
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    Well he wants to re-use it. Photons come in a large diversity, I'm pretty sure you have to first choose a range before you can start working to absorb the electromagnetic forces.
     
  6. Dave

    Retired Moderator

    Nov 17, 2003
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    This is very true. Dependant on the frequnecy you are looking at will dictate the absorption mechanism.

    Dave
     
  7. uon

    Thread Starter New Member

    May 1, 2007
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    cool...thanks so much for the replies guys and gals...

    ok ok...here're some criteria...the electromagnetic forces i'm trying to absorb will be coming from common appliances you find around a typical bedroom...eg, ceiling lights, laptops, computers, desk lights, clock etc...

    will the range of frequencies for these appliances be generally around the same vicinity??? or is the range too wide and i should really concentrate on a more specific range???

    plus, does anyone have any links or info on how much electromagnetic force different appliances emit???

    thank you so much...greatly appreciated

    P.S the water idea sounds promising...like...this doesnt HAVE to be technology, like the simpler the absortion and conversion mechanism, the better...:)

    P.S.S some links to papers on this subject would be great too...so that i can reference studies and info on the matter...like i said, i'm not a physicist, just a designer...:)
     
  8. uon

    Thread Starter New Member

    May 1, 2007
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    o...one more thing...anyway to absorb AND store this energy/emf/i'm confused...
     
  9. kubeek

    AAC Fanatic!

    Sep 20, 2005
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    My guess is that the total energy around is in the range of mili-watts, but surely less than one watt.

    And this is just the raw energy that is out there. The efficiency of using it will be very low even with a complex design.

    What sort of device are you thinking about to power?
     
  10. nomurphy

    AAC Fanatic!

    Aug 8, 2005
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    Sure you can, but just realize that any energy that you "absorb" will be seen as a "drain" by your electric company and thus turn up on your monthly bill.

    (Most appliances are 50-60 Hz.)
     
  11. Salgat

    Active Member

    Dec 23, 2006
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    I just want to state that what your asking for sounds incredibly impracticle. Whatever EMF that might leak from your common appliances is probably extremely low, and would probably just be an additional load on the circuit. Thats my opinion on it.
     
  12. thingmaker3

    Retired Moderator

    May 16, 2005
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  13. Dave

    Retired Moderator

    Nov 17, 2003
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    To me the problem is converting the absorbed energy into something useful. RF and microwave field absorption generally dissipates the energy in a dielectric object (typ. water based) as heat - where do you go from there?

    Dave
     
  14. uon

    Thread Starter New Member

    May 1, 2007
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    Wasnt powering a particular device...was gonna rechannel this energy into an induction charging plate for portable devices...
     
  15. goodbyegti

    Well-Known Member

    Apr 28, 2004
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    The force on an object due to EM radiation is given by Poyntings theorem:

    In a nutshell:

    Force = (N x Area) / (speed of light)

    Where N is the power per square metre.

    For example, assuming a 100W lightbulb is 10% efficient the force per square metre exerted on a black object a distance 1m away is:

    [ (100W x 0.10) / (4 x pi) ] / (3 x 10^8) = 2.7 x 10^-9

    For a perfectly reflecting object the force will double but in any case it's tiny!
     
  16. leberk

    New Member

    May 5, 2007
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    Well if you use a high impedance DC voltmeter with neg cxn to good gnd and pos in your hand you will read about +.1 volt. No doubt that can be stored in a capacitor. Multiple capacitors should multiply the energy stored. Right?
     
  17. cumesoftware

    Senior Member

    Apr 27, 2007
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    Well, as I said. I recommend an iron box to "sink" all the electromagnetic waves.

    Like Thomas Andrews said: "She is made of iron Sir! I assure you she can sink!"
    Dark humor. LOL:D
     
  18. thingmaker3

    Retired Moderator

    May 16, 2005
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    Just hook up hundreds of thousands of humans in series-parallele and you can... waitaminute, some guys with suits and dark glasses are at my door. I'll be right back.
     
  19. uon

    Thread Starter New Member

    May 1, 2007
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    yeah...was gonna rechannel the energy if possible...can this be done then in favour of storing it???
     
  20. kubeek

    AAC Fanatic!

    Sep 20, 2005
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    What does "rechannel" mean today?
     
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