Nathan Stubblefield Earth battery/Self Generating Induction Coil Replications

[IotaYodi]

Testing it with aluminum is a good idea. You may or may not get higher voltage spikes. The resistance is less with the aluminum wire thus better current flow,but the intensity of the magnetic field and its collapse as a whole will diminish without the iron wire on the "primary"coil.  Adding the "3rd" coil around the basic primary coil using aluminum wire may get better results. Adding an extra iron wire on the "primary" making it tri filar may give you even more force on the copper.

Dont forget the vertical electrostatic potential he used with the trees and what not. Every meter is another 100 electrostatic volts.

I do believe I found a way to test "soft" iron cores with an old color tv or monitor. Place the iron on a strong magnet for awhile or make an electromagnet then put it up against the screen. It seems to work well. I tried a 3/4 inch rod and it showed nothing,yet a piece of galvanized iron wire and another steel rod did.

Nice work Laser!       

[hoverdj]

Hi all.
I've been lurking and reading...and reading...and reading...for the past several weeks. Good stuff here.

I have been very interested in induction coils for quite some time. About 18 years ago, I obtained a reprint of a book from 1909 "Design and Construction of Induction Coils". I have always wanted to build one, but never got around to it...until I came across the Stubblefield coil.

Anyway, a couple things I wanted to point out...

1) That "soft iron rod" posted by lasersaber will likely give the best results. I've also seen these on eBay (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=300376782398). This posting has a nice description.

2) As for using a less costly soft iron core, my period book recommends the method used by Conrad for larger coils (like Bill's MIT coil). For coils producing up to 4" sparks, an iron bolt is deemed sufficient. That said, both of those could be improved by further annealing the iron. Simple to do: place the bolt or wire in a steel water pipe and cap the ends - loosely. Place this in your BBQ on a bed of hot coals and cover it with more coals. Let the pipe and it's contents reach a cherry red color, and then slowly cool. Mine took about 12 hours before I could hold it.

3) How this next part relates to the NS coil remains to be seen. But for your standard induction coils, the power coming from the secondary "is directly proportional to the number of turns on the primary and secondary...thus, if there are 10 turns on the primary and 1000 on the secondary, there will be 100 times as high an electromotive force developed on the secondary as that employed in energizing the primary, while the amperage will also be proportionately reduced."

Darryl

[jeanna]

Hi Darryl,
Welcome to this stubblefield makers group!

I want to thank you for that description on annealing the iron.
I took a metals class a couple of years ago and I thought that simply heating it like this would do, but I was never sure, so I really appreciate the confirmation.
I think it is the most important piece we all missed.
(and... since it is the very beginning of a new one, I was waiting for assurance that what I start with is the right thing.)

Since lasersaber has made a successful one, my plan is to copy/replicate his coil as much as I can.
I already have 13 that don't quite work and mostly that is because the core gets and stays magnetized.

Lasersaber found a great source for the wire, and I recommend that too.

So, welcome, and please keep us posted!

thank you,

jeanna

[hoverdj]

Thanks Jeanna.
Out of curiosity, how much is that wire after currency conversion and shipping? I emailed the company for information, but never got a reply. I ended up getting some glass insulated wire of ebay. Just got it today and wound my first layer. The insulation is pretty brittle and I ended up with a short, so I may end up going with the wire from the UK after all.
Darryl

[jeanna]

Yes, most wire is varnished and not bare as well.

I got 3 rolls because I want to make 2 coils that match each other.
I paid $40 or 50 I think after the conversion.
I chose royal mail int'l and it came in just under a week so I recommend that because that part was very reasonable.
You just need to be there to sign for it.

I got the .51mm which should be like the 24gauge, and it looks pretty thin.
I am thinking I will order some fatter wire later on.

jeanna