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BELL SYSTEM TECHNICAL JOURNAL 



curves in Fig. 15 show how nearly correct these relays have been 

 designed for conditions where the operating ampere-turns are 260 

 and the rcla\s remain operated from 150 to 000 minutes per day. 



ti^. 1 = 



The capital cost and annual ciiar.ne tii;uris ^liould l)i' l.iken <is rclatixc 

 only as the correct values will vary with manufacturing conditions 

 and with the cost of power for different localities. 



