Fig. 2,065.—Westinghouse field frames and bearings for synchronous booster rotary converter. The frames consist of heavy cast yokes. The poles are fastened to the frames with through bolts. The bed plate is in one piece for the small machines and in two pieces for the large ones.
Ques. For what service is the synchronous booster method desirable?
Ans. For any application where a relatively wide variation in direct current voltage is necessary.
It is particularly desirable for serving incandescent lighting systems where considerable voltage variation is required for the compensation of drop in long feeders, for operation in parallel with storage batteries and for electrolytic work where extreme variations in voltage are required by changes in the resistance of the electrolytic cells.
Fig. 2,066.—General Electric motor generator set consisting of 2,300 volt synchronous motor and 550 volt dynamo.
Motor Generator Sets.—The ordinary rotary converter is the most economical machine for converting alternating currents into direct currents, and where slight variations in the direct current voltage is necessary, they are mostly used on account of their high efficiency, and because they are compact.