234 Prof. E. Taylor Jones on most Effective Primary 



At the points marked a, b, c on the curve the frequency- 

 ratio has the exact values 3, 7, 11, and the efficiency in these 

 adjustments is a maximum. The efficiency curve is also> 

 shown in fig. 3, by the line DEF, the ordinate o£ which 

 represents PU 2 sin 2 <£. 



Fig. 3. 



1/P 



Curve CBA shows the increase of maximum secondary potential accom- 

 panying the addition of series self-inductance to the primary circuit 

 of an induction-coil. The abscissa 1/Jc 2 is proportional to the total 

 self-inductance of the primary circuit. The ordinate represents the 

 greatest maximum of U sin <f> (see figs. 1 and 2) at each stage. Curve 

 FEU shows the variation of efficiency. 



