NO-LOAD CUIIKKNT. TOWKR FACTOR, ETC. 71 



= J 0,40 ampere. This is in addition to the core-loss com- 



ponent of 0,038 ampere. Consequently, when the secondary 



;<> amperes at unity power factor, the primary current 



.:ide up of two components, the magnetising component 



of 0/20:5 amp. and an energy component of (0,40 + 0,088 =) 



. The resultant current flowing into the primary 



is equal to 



VO,203 a + 0,43b a = 0,484 ampere. 



^equently, for the power factor at one-tenth load we 

 have 



184- 



Similarly, when the energy component of the primary 

 nn-rent has increased to 1,00 ampere, the resultant eurr. 

 1 to 



V0,208 a + 1,00* = 1,0-2 am] 

 and the power faet.-r hecomes 



. results of these few examples show clearly tliat 

 power factor at first increases very rapidly for a small increase 

 in the energy component, ami that at comparatively small 

 it; power factor usually reaches a hijji value. I'.y 

 iar calculations, power factors for otht-r values ot' the 

 ;t may he obtained, and from them the power 

 fact- HI may he pi. .tied. \Yheii tl 



g iioii-iiidu.-tiv.-, has I :.r of less 



unity, the primary power factor will, for all usual designs, 

 be siihstantially the saiix load as the secondary power 



factor. 



rious loa<K may he ohtained as shown 



in Tahle '.. In the . cidumns the load >n the trans- 



1 he third enliiui! ^ the core loss, 



