DSpace@MIT

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering, 1925."June 1, 1925."Includes bibliographical references.Statement of purpose: The purpose of this research into solar control of street lights was to experiment and attempt to develop some means or apparatus whereby an effective control of an electric circuit could be obtained by means of the varying light intensities from sunrise to sunset. This meant that some form or other of a sun valve must be developed which would operate to turn off the street lights at or before sunrise and to turn them on again at or after sunset. Naturally, ideal operation would cause the lights to be turned off or on just as twilight merges into daylight and vice versa. The other limit should be that the valve should not operate later than sunrise or earlier than sunset. Off course, the time before sunrise and after sunset at which the valve would operate, if that is possible, is dependent upon the season of the year- the time varying with the variation in twilight which, of course, is longer during the summer months. Though other methods of controlling street lights have been proposed and a few installations actually put into operation, they are, for the most part, based on some clockwork arrangement. However, this problem is concerned with solar control through some form of a sun valve and therefore no research or development has been undertaken along any but this one line.