Kinsley — Discussion of Series Dynamo-Electric Machines. 115 

 (4) E= ""^ 



1 + 6i 



Impose the condition that n = a constant = 1400 

 It has already been found that 



a = 0.007 and 

 b = 0.004 



(8) E= «•«■' 



1 + 0.004 i 



This is the equation of an hyperbolic curve having the 

 asymptotes 



and 



_ an r^.-r. 1 



E = -1- = 24o0 when i = CO 







i = — = — 250 when E = 00 



6 



See fig. 4. 



The characteristic at a constant speed of n = 1000 has the 

 equation 



^^^ ^ = 1 + 0.004 i 



and can be plotted without difficulty. 



See fig. 6 JJ'. 



If we impose the condition that i = a constant = 120 



E (1+ bi) = «ni from (4) 



(10) E= 0.567 n 



See fig. 5 BC 



when the constants are substituted. 



Equations (9) and (10) are the equations of the lines of 

 intersection of planes, parallel to the co-ordinate planes, with 

 the characteristic surface. 



These planes will limit the solid and bound the surface 

 within the limits used in this particular case. 



