296 



ELECTRICAL MACHINERY 



magnetic leakage; an increase in either of these factors pro- 

 ducing an increase in the regulation. 



v -.^ 10 20 30 40 50 

 Load current 



FIG. 186. Power Factor and Efficiency Curves of a Small Transformer. 



Magnetic Leakage. The magnetic field, upon which 

 the operation of the transformer depends, is generated 

 by the primary coil; all of this magnetic flux does not 

 thread the secondary winding as some magnetic lines leak 



FIG. 187. An Elementary Transformer, Showing Leakage Flux at 



a, a, a, etc. 



across from one part of the core to another without inter- 

 linking with the secondary coils. In the elementary form 

 of transformer, shown again in Fig. 187, the leakage flux 

 takes the path indicated at a,a, etc, while the normal flux 



