1268 THE BELL SYSTEM TECHNICAL JOURNAL, NOVEMBER 1954 



adjustment resulting from use, time or weather conditions, which might 

 affect the abihty to accurately send or receive dial pulses. 



To achieve the accuracy of timing reciuired of dial governors, it was 

 recognized that a general theoretical analysis which defined speed of 

 governors would be beneficial. The late C. R. Moore investigated this 

 problem in the thirties, and derived from theoretical considerations, 

 general ec[uations of motion relating to governors. The relationships 

 derived by the Moore analysis are extremely useful in that they can be 

 used to indicate the influence of various design factors on the performance 

 of a governor. This theory was applied in developing the new go^'ernor 

 used in the 7-type dial of the 500-type telephone set* and will be pre- 

 sented in this paper. To better demonstrate the operating characteristics 

 of the new governor, it will be compared with a previous governor which 

 was used in an older type dial. Photographs of the new governor as it is 

 assembled in a dial are shown in Figs. lA and IB. 



Fig. 1A — Front view of 7-type dial. 



* Inglis, A. H., and Tuffnell, W. L., An Improved Telephone Set, B. S.T.J. , 

 30, pp. 239-270, April, 1951. 



