KENNELLY. — OSCILLATING-CURRENT CIRCUITS. 383 



energy remaining in the system. "We may call this quantity O.*?, for 

 brevity, the semi-system-energy. Since there can be no dissipation 

 of energy from such a circuit devoid of joulean and hertzian resistance, 

 the semi-system-energy Os does not vary with time as the circle rolls 

 along the OV axis. CCC and LLL are cycloids differing l.SO° in 

 phase. 



Inductance- Discharging Oscillations in a Simple Resistanceless Oscil- 

 lating-Current Circuit. — We have thus far considered condenser- 

 discharging oscillations. If, however, the inductance be charged with 

 current and magnetic energy fi-om a separate source, and this source 

 is suddenly and sparklessly removed, while the condenser circuit Fig- 

 ure 1 is closed at T T, the inductance will set up a series of discharging 

 oscillations. If we assume that the initial steady current strength /(,, 

 at the moment of release, is equal to the maximum cyclic value of the 

 current in the case already considered, then the oscillations of the 

 inductance-discharging system will differ only in phase from the oscil- 

 lations of the condenser-discharging system already discussed. Thus, 

 if the current in the inductance were 6.3246 amperes at the instant 

 of release, and the condenser were initially without charge, the oscil- 

 lations of the system would be those of Figure 5, except that the time 

 would start from the instant denoted by 90° in that diagram. If the 

 initial direction of the current in the coil were reversed, the starting 

 point in time would be at 270° in Figure 5. Consequently, with con- 

 denser-discharging oscillations, we start in Figure 5 with ^ = 0, either 

 from the phase of 0° or of 180°, according to the direction of the 

 p. d. impressed upon the condenser; while with inductance-discharg- 

 ing oscillations, we start with t ^= 0, either from the phase of 90° or of 

 270°, according to the direction of the current impressed upon the 

 coil. The sequence of all the phenomena will then remain in each 

 case as presented in Figure 5. 



Not only Figures 2 and 5, but also Figures 3 and 4 apply equally to 

 inductance and condenser-discharging oscillations. The diagrams of 

 Figure 4 apply more directly, however, to inductance discharges, and 

 those of Figure 3 to condenser discharges, because in the former the 

 initial current is the independent common variable ; while in the latter 

 initial p. d. is the independent common variable. Thus, if in Figure 1 

 the inductance was initially charged with a current of 10 amperes, and an 

 energy of 5 joules, the maximum cyclic current Iq would be 10 amperes, 

 the r. m. s. or virtual current, /, 7.071 amperes. The maximum cyclic 

 oscillating p. d. Uq, in the absence of resistance, would be 1581.14 

 volts, the r. m. s., or virtual, p. d. U, would be 1118.0 volts, the 

 maximum cyclic power P^ would be 7905.9 watts, and the maximum 



