large & efficient electro magnet

[Luciano]

Hi,

Use wrought iron for the nucleus of the coil.

More about that here: (Read the book from page 1).
http://books.google.com/books?id=4KW...jLb0wQpLXST66c

The whole book in a 44MB PDF file.
(Scan of the 3rd edition of the book printed in the year 1900).
http://ia310925.us.archive.org/1/ite...00ewinrich.pdf

The reprint of the book in 2003:
(Same as 3rd edition of the book printed in the year 1900).
http://search.barnesandnoble.com/boo...=9781929148110
(113 years after the original book printed in 1891).

The author: James Alfred Ewing (1855 - 1935)
http://en.wikipedia.org/wiki/James_Alfred_Ewing

* * *

Why do you need to connect an oscilloscope?

Possible alternative solution to measure the strength of the coil's magnetic field:



Best regards,

Luciano