Nation projector carbons (1935)

Record Details:

Title:
Nation projector carbons
Date:
1935
Publisher:
Toronto : Canadian National Carbon Company Ltd.
Volume:
Nation projector carbons
Leaf #:
00024
Language:
English
Subjects:
Motion Pictures, Motion Picture Technology
Collection:
Books
Format:
Books
Contributor:
Media History Digital Library
Sponsor:
Media History Digital Library
Coordinator:
Media History Digital Library
Description:
Date Added:
May 30, 2024
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National Projector Carbons nation has an effective current range of 16 to 20 amperes but operates most efficiently at 18 to 20 amperes. However, to fully demonstrate the influence SCREEN CRATER Figure 12 Method of Observing Effect of Current on Crater of current on crater area and arc performance, the test was started at ten amperes and increased in successive steps of two amperes each to 24 amperes. It was observed that at ten amperes the light wandered about on the tip of the positive carbon, due to the fact that the tip was too large for the amount of current being employed, with the result that the light was unsteady and required considerable attention to keep it adjusted. As the current was increased, the light became more steady and the white hot tip or crater, increased in size. At 18 to 20 amperes, the point of maximum efficiency, the arc burned quietly and steadily and the white hot spot was about as large as it is possible to obtain with steady burning from the combination of carbons used. As the current was increased above 20 amperes, there was a tendency for the arc to become unsteady, due to the overloading of the combination. The photographs, Figures 13 to 20, inclusive, show the incandescent craters at the various amperages. They were taken with the camera and lamp in a fixed position, consequently the pictures show the relationship between size of crater and amperage. 20