A New Alternating-Current Projection Arc

A new type of arc operated on alternating current is a desirable substitute for the low-intensity, direct-current arc used in the majority of motion picture theaters. This arc is a modification of the well-known white-flame arc, in which the light sources are concentrated at the electrodes by using heavy currents and low arc voltages on specially designed carbons. — It is operated at current densities higher than those employed in direct-current arcs, and produces a screen light of a blue-white color similar to that obtained with the direct-current, high-intensity arc. The bluish white screen light is remarkably steady and uniform. The power required to produce a given screen illumination is considerably less than that required with the low-intensity, direct-current arc.

Print ISSN

0097-5834

Published

1933-08

Content type

Original Research

DOI

10.5594/J02038