Tesla's "COIL FOR ELECTRO-MAGNETS".

[Magluvin]

Hey Mags,

Is it not logical to expect that some lifter designs may use multiple coils as a way to increase ampere turns for more lifting power or to allow for a more physically compact unit?  Any increase in DC resistance can be compensated for via application of a higher DC voltage to maintain a given DC current.

Heating of the windings is usually a limiting factor with these lifters, and you will note that the mfg page cited specifies a 75% or so duty cycle for most of their lifters.

I just don't see anything in that 1914 image that is not consistent with a standard DC lifter. 

PW

Hey Pico

Im just stating what I read and see.  The page of the pic I posted says flat conductors. And so does the modern magnet link claim this in the repair section.

Of the 2, the pic posted seems to have 4 layers if Im interpreting the cut away view properly. And the pics of the repair coils look as to have 2 layers, like pancakes made of flat conductors and stacked ready for butter and syrup. Possibly they are in series with each other, dont know yet.  Just laying out what I think of it so far. Not saying they are bifilar or not. There is no indication so far.

Mags

[picowatt]

Hey Pico

Im just stating what I read and see.  The page of the pic I posted says flat conductors. And so does the modern magnet link claim this in the repair section.

Of the 2, the pic posted seems to have 4 layers if Im interpreting the cut away view properly. And the pics of the repair coils look as to have 2 layers, like pancakes made of flat conductors and stacked ready for butter and syrup. Possibly they are in series with each other, dont know yet.  Just laying out what I think of it so far. Not saying they are bifilar or not. There is no indication so far.

Mags

Mags,

Check out the following:

http://www.jobmachineryinc.com/generator_sets.htm

http://magstargenerator.com/

If there was an easier way (i.e., more energy efficient), don't you think a tight profit margin industry like a scrap yard would be using it?

There are PM lifters available for lifting flat sheets, but for irregularly shaped scrap, big DC electromagnets rule. 

PW

[Magluvin]

Mags,

Check out the following:

http://www.jobmachineryinc.com/generator_sets.htm

http://magstargenerator.com/

If there was an easier way (i.e., more energy efficient), don't you think a tight profit margin industry like a scrap yard would be using it?

There are PM lifters available for lifting flat sheets, but for irregularly shaped scrap, big DC electromagnets rule. 

PW

Hmm, not gettin your drift. Im not arguing that they are DC or AC. 75% duty cycle indicates pulsed DC. Are you saying that you dont think they are wound with flat conductors?  Not sure of the point.


Mags

[picowatt]

Hmm, not gettin your drift. Im not arguing that they are DC or AC. 75% duty cycle indicates pulsed DC. Are you saying that you dont think they are wound with flat conductors?  Not sure of the point.


Mags

Mags,

Not at all.  I fully agree that many, if not all, of these lifting magnets use flat windings.  Particularly wrt the more modern versions.

I just don't see anything that supports Synchro1's claim that the lifter depicted in the 1914 image operates on a 6 volt pulse using a capacitor that somehow causes it to remain magnetic until, I assume, a second pulse is somehow applied.

That is basically how he described the operation of that "industrial electromagnet" depicted in the 1914 image that he stated was a "Tesla Scrap Yard Magnet".

I see nothing in that 1914 image that is not consistent with a standard DC electromagnetic lifter and wondered if Synchro1 had any evidence to support his assertions, or if that was just speculation on his part.

PW 

[Farmhand]

Tesla also used flat conductors for ordinary transformers for obvious reasons.

http://www.google.com/patents?id=p5g_AAAAEBAJ&pg=PA2&source=gbs_selected_pages&cad=2#v=onepage&q&f=false

Page 2 lines 11 to 19.

In practice for apparatus designed for ordinary usage the coil is preferably constructed on the plan illustrated in Fig 3 In this figure LL are spools of insulating material upon  which the secondary is wound in the present case however in two sections so as to constitute really two secondaries. The primary C is a spirally wound flat strip surrounding both secondaries B.

Flat copper strips make good coil conductors in some applications. The most obvious reason to me would be the reduced resistance and increased surface area. A flat strip primary would give good coupling to a secondary winding even with not many turns itself simply because of how much of the secondary winding area the primary strip is in close proximity to. Similarly for a large spiral coil if the turns are flat strip the inductance would be more for the turns I think, because more copper is in closer proximity per turn.

Just an uneducated look at the flat strip conductors.

Happy to see the discussion heated up. I don't want to seem as though I am trying to stifle discussion, people should feel free to speak their mind, within reason.

Cheers