CHAPTER III 

 THE CONTINUOUS CURRENT GENERATOR 



19. E.M.F. of a C-C. Generator. In calculating the 

 voltage generated by any machine we start from the funda- 

 mental rule that if a conductor cuts a magnetic field at the 

 rate of 10 s lines per second it generates one volt of e.m.f. 

 Therefore, to find the e.m.f. generated by any machine 



FIG. 53. Possible Field Distribution in the Air Gap. 



it is only necessary to calculate how much flux the armature 

 winding cuts per second. First, a single coil armature 

 will be considered and then the more complicated windings 

 will l)e taken up. 



E.M.F. form for an Elementary Generator. Suppose a 

 ring-wound armature with only one coil, the two ends of the 

 coil being connected to two slip rings, as in Fig. 53. These 

 rings ;in- represented one inside the other; really they would 



