Hallberg, Josef Henrik, 1874- · New York city, The Moving picture world · leaf 47
esurrounded bv copper wire, successive impulses ofcurrent are produced. The frequency of the reversals depends upon 40 MOTION PICTURE ELECTRICITY the speed at which the magnet poles are rotatedpast the soft iron core. CYCLES By modification of the number of rotating magnetpoles, and the speed at… … Fig. ii your attention is called to Fig. n, in which the horizontalline represents time; the curves above the line representpositive current generated, and the curves below the linerepresent negative current. The vertical line on the leftis a scale of amperes running from zero to 40 above…
Motion picture theaters · Electric lighting
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
![An illustration from [Electric engineering.] (1902)](https://img.insideoutlibrary.com/img/200/ia-electricengineer02inte-188-84.webp)
