THE CONTINUOUS CURRENT GENERATOR 



Action of Commutator. To make the simple machine 

 of Fig. 53 give a current which, in the external circuit, is 

 uni-directional, it is necessary to connect the ends of the 

 coil to the two segments of a two-part commutator and 



37T 



47T 



Time 



FIG. 55. E.M.F. Wave Form, With Commutator. 



to so place the brushes on the commutator (diametrically 

 opposite to one another) that, at the same time that the 

 e.m.f. of the coil reverses the connection of the coil to the external 

 circuit reverses. When this is done a pulsating, uni-direc 



FIG. 56. Connections and Brush Position for One-coil Armature. 



tional current as shown in Fig. 55 flows in the external 

 circuit. 



The commutator and proper position of the brushes 

 to give such a current in the external circuit are shown in 

 Fig. 56, where the brushes are shown inside the commu- 



