THE Tit A \SFOiniER 17'.' 



<>f the primary leakage flux, therefore, is to oppose the flow 

 of current into the transformer. 



The mint*, of the secondary coil, acting alone, is such that the 

 top of the coil is at a higher magnetic potential than the bottom 

 of the coil. That is, plane c is at a higher magnetic potential than 

 plane (I, and therefore a flux fa tends to pass from c to d through 

 >wn. Flux 60 is called the xccomlarif leakage flux. 

 path is not linked by the primary, the secondary leakage 

 flux is proportional to the secondary ampere-turns only, fa 

 induces an emf. in the secondary, lagging the secondary current 

 7j by 90. This is also a reactance voltage, and the component 

 which balances it leads the secondary current by 90. This last 

 voltage is denoted by I 2 X 2 . The secondary reactance opposes 

 urrent flowing out of the secondary just as the armature 

 mce of an alternator opposes the current flowing out of the 

 armature. Both the primary and secondary reactances of the 

 ormer have the same effect on the regulation of the trans- 

 former as the armature reactance of the alternator has on the 

 regulation of the alternator. 



In that part of the core which is surrounded by the secondary 

 winding the mutual ilux <f> and the secondary leakage flux fa are 

 shown in opposition. As < is produced by the joint ampere- 

 turns of primary and secondary, and fa by the ampere-turns of 

 the secondary alone, < and fa are almost never in phase with 

 each other, but are usually out of phase by an angle greater than 

 90, as shown in Fig. 174 (a). Two separate fluxes in the core 

 do not actually exist at the same instant, but merely the resultant 

 tlux. found by combining </> and fa. The primary leakage Ilux 

 o, and the secondary leakage ilux fa have the same general 

 direction in the space between the primary and secondary roils. 

 In the actual transformer, the leakage ilux paths are not 

 uple as those indicated in l-'iu. IT:;. That is, part of fa 

 Omeof 1 idary t urns, but not all. el c. 1 Io\\ .-\ -r. 1 he 



equivalent effect of <j>i and fa is readily determined in theordinary 

 former by simple measurements, as is described later. 

 In practice, the primary and secondary windings are not 

 plac,-d 01 .-linwii in Fii:>. 1 To. IT'J and 17 



widely d. lame primary and -<<< nidary 1 



fluxes would re>ult. 



