Original poster: "Neal Namowicz" <mr_neal@xxxxxxxxxxxx> Dr. R.:I'm just tossing a theory out here, but is it possible that there is a material, or a material in a specific shape out there, that would reflect the eddy current back up? I'm thinking, though, that could go in at least one of two ways; overcoupling, or, achieving the same results using a smaller than usual primary. Just a "layman's" thoughts from one who's coffee hasn't completely kicked in yet. (jet lag :)
Neal. ----- Original Message ----- From: "Tesla list" <tesla@xxxxxxxxxx> To: <tesla@xxxxxxxxxx> Sent: Friday, April 21, 2006 1:31 PM Subject: Re: Transformer location/Safety
Original poster: "Gary Peterson" <gary@xxxxxxxxxxxx>What is the shape of an individual eddy current? If it could be seen, would it look like tapering tornado-like vortex, a sheet rolled-up into a cylinder, or something else?Gary PetersonOriginal poster: "D.C. Cox" <resonance@xxxxxxxxxx>Eddy current losses ( circular in nature) induced in the aluminum by the primary circuit could also increase losses from the pri. The object is to keep as much energy as possible in the pri and then couple it into the sec without "giving it away" in the form of parasitic losses such as mounting metal components directly under the primary when they do not have to be mounted there in the first place.I agree with your excellent accessment of skin depth and it's effects. Dr. ResonanceOriginal poster: "Bob (R.A.) Jones" <a1accounting@xxxxxxxxxxxxx> Hi, The shielding effectiveness of a infinite metal sheet to a magnetic field is a function of the skin depth in the metal at the frequency of the magnetic field. If the thickness of the sheet relative to skin depth is small the shielding will not be effective. (say 10% reduction) If the thickness of the metal sheet is large relative to the skin depth the shielding will be very effective (say 90% reduction). From memory the skin depth in aluminum at the usually Tesla coil frequencies is less than a 1mm so 1mm of aluminum sheet should reduce the field to say less than 10%. Other factors such as joints and size of the shield will have an effect as well. Robert (R. A.) Jones A1 Accounting, Inc., Fl 407 649 6400