60 Proceedings of the Royal Society of Victoria. 



Vol. copper I 

 Vol. iron '^K 

 where K and I are these losses per cm.'' 



•*• "^+"^=3;|r^ 4 ^"^-^ 



a form very suitable for the determination of x^-\-x.^ for core 

 transformers. 



For example, if s = l, 1 = 10% K = 15.10^ <7i=.5, ^.3=. 7, Q = .58.3 

 as before, x■^-\-x^ for any core transformer designed on these data 

 is given by 



X, + .T.,= - — ,,1.14. 



For a core transformer of the H type, simply wound, in which 

 the rectangular opening in the stampings is 10.2x25.2 cm., and 

 the width of the surrounding iron strip 8.9 cm. (See § 57) 



A' = 2x 2.5.2 = 50.4 cm. 



A=106.4cm. 

 and if /x.= 2250, 



cKi+X2=.00075. 



54. If a core transformer be wound with 2/ layers, i each of 

 primary and secondary arranged alternately, and if D be the total 

 depth of the windings, it can be shown that 



4- ■^T) 



aji+a.2= -— ; — ^ X sum of the mean radii of all the layers, 



^-— — ,^ X mean of the mean radii of all the layers, 

 3 A cri' 



which by exactly similar reasoning to that in § 5,3 can be put into 



either of the forms, 



.... 1 A'^ volume of copper 



P 3/aQA''^ volume of iron 



1 X' si 



or x-.-\-x^= - 



'^ ' P S/xX" QK 



If there be / layers of one coil ajid / + 1 of the other, then we 

 may take 



,1 X" zl 



'^ ' /(/+1) 'iy.X" QK 

 This result and those in § 53 will be sufficiently accurate for all 

 practical purposes when the coils are rectangular in plan. 



