TESTS OF TRANSFORMERS. 



107 



Perhaps the experimental investigation of greatest interest is 

 that of Messrs. Beeton, Taylor, and Barr, on account of an inge- 

 nious method of obtaining various wave forms from a single alter- 

 nator by the use of a piece of apparatus called an injector, 

 by means of which resistance, self-induction, or capacity can be 

 thrown in the circuit at any instant during the period at will, 

 producing wave forms of the P.D. which could only have been 

 obtained otherwise by a series of dissimilar alternators. 



The conclusions arrived at experimentally are 



1. That if the E.M.S. value of the applied P.D. is constant, and 

 the area of the P.D. wave is constant, then, whatever be the shape 

 of this wave, the total iron loss cannot vary. 



2. That if the E.M.S. value of the applied P.D. is constant, but 

 the area of the P.D. wave varies, then, whatever be the shape of 

 the wave, the total iron loss will vary by an amount which is only 

 dependent upon the area of the P. D. wave. 



These results are in complete agreement with the preceding 

 theory. 



TESTS OF TRANSFORMERS. 



64. Tests on Ferranti standard transformers furnish the 

 following results : 



TABLE V. 



FREQUENCY 50 CYCLES PER SECOND. 

 Trans p ormation Ratio. 



