12 Proceedings of the Royal Society of Victoria. 



W = i7e/T-SinS 



or 



hence (as the core loss per second H^^W/T) 



H,=ize/— SinS 

 ^ - o- 



T,SinS , 

 = \rS'n' ^ (see § 9). 



In § 9, P'2 the total power passed down to and developed in 

 the secondary was shown to be equal to 



SO that the different portions Hj, H^ and P'2 into which P^ is 

 divided are accounted for, and in § 13 are given the secondary 

 copper loss H2 and the output P^ into which P'2 is subsequently 

 divided. 



Transforming the above expression for H3 to one in terms of & 

 and by § 13 we find 



and collecting the other power expressions 

 E^^Cos> 



Pl=:P2 + H, + H2 + H,. 



It is worth noting that, as M/D = l to the first order, the iron 

 loss H3, and the flux F will, to the same order, be constant 

 throughout the range of operation of a transformer. 



15. The efficiency rj, of the transformer being 



P2_ P2 



-P1-P2 + H1 + H2 + H3 



^Oos> 

 we have .; = ^~~&'O^^V~~Zr , 



Tj T2 



~ — ?~^' ^^^*'® O = Sin 8 + - + (9 Cos ^ j Cos ^ + 



