摘要:

Object.—To provide a self-explanatory schedule for routine work.Method.—Sums and differences of observations are taken (as in the late Professor S. P. Thompson's method and others).A sufficient number of values are solved in general terms, so that working an example is reduced to filling in values in known equations. This work is expedited very materially by means of the schedule. Nothing but a slide rule is necessary, and the actual calculations can be carried out by persons with no great knowledge of mathematics.Results.—An example has been worked out up to the 17th harmonic in 50 minutes, thus comparing favourably in this respect with other methods. Furthermore, the results are given in the form E sin (θ + α), which is more useful than EAsin θ + EBCOS θ.In cases where harmonics higher than the 17th are present in appreciable magnitude, an increased accuracy in the analysis is obtained for a given number of ordinates.

DOI:10.1049/jiee-1.1919.0058

出版商:IEE    

年代:1919

数据来源: IET

DOI:10.1049/jiee-1.1919.0059

出版商:IEE    

年代:1919

数据来源: IET

DOI:10.1049/jiee-1.1919.0060

出版商:IEE    

年代:1919

数据来源: IET

DOI:10.1049/jiee-1.1919.0062

出版商:IEE    

年代:1919

数据来源: IET

摘要:

The authors first consider the changes that have already taken place and are now in progress among the telephone-using public and in the labour and manufacturing worlds. The bearing of these changes on the possibilities of improvement in telephone service, on the adjustment of tariffs, and on reductions in expense is then discussed.A proposal is made for the introduction of a “unit of telephone service” as the basis of the charge made to a subscriber. By taking the duration of the conversation into account, the charge would be scientifically proportioned to the expense incurred, yet without involving technicalities not easily understandable by the subscriber.The consideration of the trend of events points to the introduction of mechanical appliances to effect the switching operations for all but those special cases of call for which expert attention is essential. The authors discuss the engineering aspect of the application of mechanical operation in the shape of “full automatic” working to large cities, and deal with the technical problems which arise both with the ultimate arrangements and particularly during the transition stages, taking London as a case presenting the maximum difficulty.

DOI:10.1049/jiee-1.1919.0064

出版商:IEE    

年代:1919

数据来源: IET

DOI:10.1049/jiee-1.1919.0066

出版商:IEE    

年代:1919

数据来源: IET

DOI:10.1049/jiee-1.1919.0067

出版商:IEE    

年代:1919

数据来源: IET

摘要:

(1) Simplified formulae are given by means of which the maximum electric stress between equal spherical elctrodes can be readily found.(2)Experimental results on sparkling voltages when the potentials of the equal spherical electrodes are equals and opposite are analysed. It is found that it a be the length of the radius of each electrodes in centimetres, the maximum potential gradient Rmaxat the instant of discharge is given by the Rmax. = 27.4 + 14.1/√ Kilovolts per cm. very approximately when the temperature of the air is 25° C. and the height of the barometer is 76 cm.(3) The sparking voltage E between two spherical electrodes, the radius of each beinga, andxbeing the distance between them, is given by E =x/f(21.4 + 14.1/√a) Kilovolts at 25° C. and 76 cm. pressure, wherefis a factor which can be easily calculated from the geometrical dimensions.It has to be remembered that these formulae do not apply to air-gaps less than 1 mm. or air-gaps so great that brush discharges take place.(4)It follows from the formulae given above that in general for a fixed spark-gap there are certain sized spherical electrodes which offer the maximum resistance to sparking. Increasing or diminishing the size of the electrodes from this value makes the spark take place more readilly.(5) The results when one electrode is earthed given in the “Standardization Rules” of the American Institute are analysed. From the results it appears that the potentials of the electrodes were not E and o, but were 0.57 E and — 0.43 E. These values of the potentials make the values of Rmax. deduced the same as the values found when the potentials are equals and opposite.

DOI:10.1049/jiee-1.1919.0069

出版商:IEE    

年代:1919

数据来源: IET

DOI:10.1049/jiee-1.1919.0070

出版商:IEE    

年代:1919

数据来源: IET

DOI:10.1049/jiee-1.1919.0071

出版商:IEE    

年代:1919

数据来源: IET