Pupi?i — Resonance Analysis of Alternating Currents. 473 



Art. LXIY. — Resonance Analysis of Alternating Currents; 

 by M. I. Pi; pin, Ph.D., Columbia College. Part II. 



Additional evidences proving the correctness of its indica- 

 tions referred to in the last paragraph will be found among the 

 results of the following experiments. 



I Y. — Location of the Origin of Upper Harmonics. 



A. Experiments with alternator of smooth core armature. 



1st Series. — The first set of experiments in this direction 

 was performed with the 10 H. P. Fort Wayne 8 pole alterna- 

 tor with smooth core armature and the Stanley 5 K. W. trans- 

 former (closed magnetic circuit). The secondary circuit car- 

 ried no load and a Cardew voltmeter indicated the secondary 

 voltage. The current which excited the field of the alternator 

 was gradually increased. The secondary voltage measured the 

 strength of this excitation. The air core transformer with the 

 resonator was inserted into the primary circuit as indicated in 

 fig. l b . The resonant rise of potential, recorded by the multi- 

 cellular voltmeter e', was carefully determined at every excita- 

 tion for the fundemental frequency and for the first odd har- 

 monic. Higher harmonics were present but very faint. The 

 results are given in Table IV and plotted in fig. 5. The initial 

 voltage in the resonant circuit was small, just perceptible in 

 the multicellular voltmeter. 







Table IV. 







Secondary voltage. 



Resonant rise in 

 due to the fundame 



volts 

 sntal. 



Resonant rise in volts 



due to the first odd 



harmonic. 



43 





122 





58 



48 





130 





65 



53-5 





136 





72 



56 





J38 





73 



62 





146 





80-5 



66-75 





152 





86 



75 





160 





94 



83 





170 





104 



88 





175 





110 



97 





185 





117 



104 





195 





128'5 



