DIRECT-CURRENT MACHINERY 



223 



Thus by installing an automatic booster the battery is made 

 more sensitive to variations of load and a better regulation of the 

 generator load and voltage is obtained. 



Series boosters are used in electric railway engineering and in 

 general power distribution to raise the voltage on certain sections 



Booster 



Trolley 



Rail Return 



FIG. 189. Series booster. 



of the line as in the case of a long feeder supplying power to an out- 

 lying section, as shown in Fig. 189. The booster field is connected 

 in series with the line and it produces an increase of the im- 

 pressed voltage to take care of the line drop. 



