382 



ELECTRICAL MACHINERY 



way converter might call for 550 volts at no load, 600 

 volts at full load, and those for a converter for a lamp 

 load 225 volts at no load, 250 volts at full load. 



Necessary Increase in Impressed Voltage. But the ratio 

 of the continuous voltage to the alternating voltage is fixed 

 and it is therefore evident that if it is desired that the 



FIG. 249. A Six-phase Synchronous Converter, Showing the Field 

 " break-up " Switch Mounted on the Frame. Westinghouse 

 Electric & Mfg. Co. 



continuous voltage should increase with the load it can 

 be accomplished only by causing .the impressed alternating 

 voltage to increase correspondingly with load. A railway 

 converter to give 550-600 volts would require an impressed 

 alternating voltage of 550 X. 612 = 337 volts, at no load, 



