328 KENNELLY-NABESHIMA— ESTABLISHING A 



rent will be splashless ; i.e., they will be sinusoidal and in cophase 

 from the very start. In such a case, because there can be no 

 reflection from the distant end, the initial outgoing current will be 

 the same, both as to magnitude and phase, as the final outgoing 



Fig. I. Diagram of A. C. Generator Connected to Line. 



current ; or there will be no transient wave. In this particular and 

 simple case, if 2q is the reactanceless surge impedance of the line, in 

 ohms, E^ the maximum cyclic e.m.f. in vector volts at standard 

 phase, the initial and final outgoing current will be 



/o = — , max. eye. amperes Z. (i) 



If the frequency of the impressed e.m.f. is / cycles per second, and 

 the corresponding angular velocity w = 27r/ radians per second, then, 

 at time t seconds after the switch closure, the instantaneous voltage 

 and current at A will be 



e = E^ sin (at instantaneous volts, (2) 



E 



i= — sin wt instantaneous amperes. (3) 



^0 



Because of the simple conditions assumed in this case, including 

 infinite line length, the current defined by (3) is instantly de- 

 veloped without the intervention of any transient. If the line has 

 "finite length, but is grounded at B through an impedance equal to 

 the surge impedance Zq, it will give rise to no reflections from B, and 

 will behave, in this respect, like a line of infinite length. Such a 

 case is represented in Fig. 12 (film 35). 



