CH. IX 



CONTROL 



197 



no advantage in this, as it merely extends the time of 

 speeding up under a low acceleration, and involves 

 coin plications in the controller connections. The motors 

 are thrown into parallel at eleven seconds from the moment 

 of starting. At this point the car has almost ceased to 



FIG. 50 



accelerate, so that it is subjected to a sudden shock which 

 would be avoided if the motors were not permitted to speed 

 up in series. Step II. is slightly rounded off, but Step Ill- 

 is well shown. 



In these experiments the parallel method gives a quicker 

 start with a greater expenditure of energy. We must not 



