摘要:

The wide range of subjects, physics and engineering, physiology and psychology, coming within the purview of the illuminating engineer is pointed out. A brief résumé of the recent rapid progress in illumination is followed by a description of fundamental principles; in particular the use of the modern conception of luminous flux in illumination calculations is described.The chief requirements of a lighting system are that the lighting should be both adequate and suitable. It is pointed out that, in the past, adequacy has generally been emphasized to the neglect of suitability. It is, however, difficult to overestimate the importance of the latter factor in good lighting and it is dealt with in some detail under the following headings:—(a) Freedom from glare and excessive contrast in the field of view.(b) Adequate but not excessive diffusion.(c) Correct colour.(d) Correct proportion of local and general lighting.As an example of the application of the results of a psychological investigation to a practical lighting problem, a description is given of a method of so designing a street-lighting system that the glare may not exceed a certain specified limit.In conclusion the opinion is expressed that the present lighting load could be at least quadrupled, with immense benefit to the community.

DOI:10.1049/jiee-1.1927.0078

出版商:IEE    

年代:1927

数据来源: IET

摘要:

At the commencement of this paper the author points out that very little advance has been made in public lighting and that the conditions are very similar to those which existed in 1913. He contends that the demands of modern civilization are such that the height, spacing and position of light sources should be re-arranged to avoid the use of very brilliant light sources and to reduce obstructions to vehicle and pedestrian traffic which are liable to endanger the safety of the public.For this purpose, it is proposed that the light sources should be centrally suspended at frequent intervals by means of span wires, which, in order to reduce the cost and to simplify control and maintenance, should support the conductors.Various examples of overhead suspension and of the usual method of supporting by means of columns are cited, with the object of comparing these with the suggested solution of the problem.It is pointed out that modern gasfilled electric lamps, due to their light weight and the little attention required, are specially suited to the suggested method of support, and that when combined with the necessary conductors the whole overhead equipment is inexpensive and not unsightly.Figures relating to the initial cost and operating expenses of the construction proposed by the suthor are given and are compared with the existing examples previously referred to. The second part of the paper deals with side streets, lanes, alleys and slums, which the author contends deserve immediate attention in order that the poorer classes may live under brighter conditions. In such cases he advocates a similar overhead construction at a reduced cost, which would result in increasing approximately two hundredfold the illumination at the dark parts.High roads and arterial roads passing through populated districts and used by motor traffic form the subject dealt with in the last part of the paper. The author proposes that this class be illuminated by means of highly concentrated light sources similar to motor-vehicle headlights and fixed at a considerable height to give the required vertical illumination advocated by automobile authorities, but so arranged that no illumination is required from the adjacent source, thus reducing the glare.

DOI:10.1049/jiee-1.1927.0079

出版商:IEE    

年代:1927

数据来源: IET

摘要:

The paper briefly describes the Holweck molecular pump and, in more detail. 10- and 30-kW Holweck demountable type valves. Precautions necessary with demountable valve installations are pointed out. The chief advantages are ability to renew filaments at a cost of a few pence, and ability to carry large overloads. Some results obtained with installations employing demountable valves are given. The possibility of larger-power single units being developed is mentioned, but short-wave work may make it unnecessary to build larger units than those developed. Perfection of details with a view to complete reliability should make for increased application of this type of valve.

DOI:10.1049/jiee-1.1927.0086

出版商:IEE    

年代:1927

数据来源: IET

摘要:

The paper discusses the construction for Naval purposes of wireless transmitting valves with silica envelopes. The main properties of silica as an envelope for high-power valves are enumerated and the valves are divided into two main classes depending on whether the anode heat is removed by radiation or by the use of a cooling fluid.A description is given of the electrode seals which have been developed to carry currents up to 100 amperes.The various types of valves and the methods of construction, evacuation and repair are described.The dimensions of standardized valves and the methods adopted for removing the heat generated in the various types of valve anodes are dealt with.The operating conditions for transmitting circuits and the methods of packing for transport are briefly referred to.

DOI:10.1049/jiee-1.1927.0087

出版商:IEE    

年代:1927

数据来源: IET

摘要:

In the first section of this paper cooled-anode valves of the transmitting, modulating and rectifying types are described, with, details regarding construction and pumping. Characteristic curves are given, and in some cases particular applications are considered.The second section deals with various factors which affect the lives of valves. The importance of the life of the valve cathode is emphasized, and means of obtaining the maximum life from the cathode are described.In the last section survivor curves are given for various types of radiation-cooled valves, showing actual results obtained on commercial stations. As such data are not yet available for cooled-anode valves, extracts are given from valve records of stations using these valves.

DOI:10.1049/jiee-1.1927.0088

出版商:IEE    

年代:1927

数据来源: IET

DOI:10.1049/jiee-1.1927.0091

出版商:IEE    

年代:1927

数据来源: IET