2 Proceedings of tli.e Royal Society of Victoria. 



In some experiments on good transformer iron of thickness .04 

 cm. (qp-)) I irdve found by means of my wave tracer^ that ju.,, and 

 8 are given in terms of B, for periods .03 and .06 sec. by the 

 curves shown in Fig. I., where the curves giving the correspond- 

 ing iron losses are also sliown. 



In these experiments the wave forms of H were peaked, that 

 is, the value of H at the crest was greater than the amplitude H^ 

 of its first harmonic. When the wave form of H is flat-topped, 

 both fXf) and 8 are smaller for the same values of Bj and 2i>. 



The values of B at the crests of the flux waves, corresponding 

 to different values of Bj the first harmonic, for the period .03 

 sec. are also given in Fig. 1, by the upper row of figures along 

 the axis of x. 



When the third and higher harmonics of H and B are 

 neglected, the above equations take the simple forms, 



M.M.F. 



Length 

 Flux 



= HSinyf// 



= BSin(a^/-S) 



Section 

 B = /i,II 



Iron losses jjer cycle HB^. ^ 



Volume of iron 4 



Iron losses per second wW„. _ 



^r^, ^-F-- = Q — SinS 



Volume oi iron cnrfx 



which relations will be used in the following approximate theory 



of the transformer. 



Notation. — The different periodic quantities considered will 

 in the text be represented by letters such as E^, Cj, E^, C„, with 

 bars over them when the conception of both their amplitudes 

 and phases is involved, while the amplitudes of these quantities 

 will be represented by the same letters without the bar. Letters 

 with the number 1 subscribed will refer to the primary, and with 

 the number 2 subscribed to the secondary circuit. 



The period of the alternations will be ^ttJiv. 



2, On the vector diagram. Fig. 2, let OR represent in ampli- 

 tude and phase the resultant flux F looped on both the primary 

 and secondary coils of a transformer. 



1 Phil. Mag., Nov., 1903. 



