THE TRANSFORMER. 



205 



harmonic electromotive forces and currents, inasmuch as non- 

 harmonic electromotive forces and currents cannot be represented 

 in a clock diagram. 



The magnetizing current, M, of a transformer is not harmonic 

 and it cannot, therefore, in strictness, be represented by a line in 

 a clock diagram. In Figs. 172, 173 and 174, however, M is 

 represented by a line. The current so represented is called the 

 " equivalent harmonic magnetizing current" (see Art. 1 15). 



Case i. Non-inductive receiving circuit. In this case the 

 current I" produced in the receiving circuit is in phase with 



hr 



Fig. 175. 



E", as shown in Fig. 172, and, according to Art. 98, /' must, 

 therefore, be in phase with E' . The line OM represents the 

 magnetizing current in the primary coil, and the vector sum of 

 OM and /' represents the total primary current. The vector 

 03> represents the harmonically varying core flux. Figures 

 172 to 175 all represent a 2 : I step-down transformation. 



Case 2. Inductive receiving circuit. In this case the current 

 I" produced in the receiving circuit lags behind E" by an 

 angle 9 of which the tangent is equal to XjR t where X is 

 the reactance and R is the resistance of the receiving circuit. 



