Triode Generator with Two Degrees of Freedom* 701 



a kind of oscillation hysteresis is obtained, which, apart from 

 its importance in technical applications, is of interest from a 

 physical point of view. 



The normal experimental arrangement is shown in fig. 1, 

 where an oscillatory circuit L 2 C 2 is shown coupled through 



Fig. 1. 



-MMi— <M 



the mutual induction M to the circuit L 1 C 1 belonging to a 

 normal triode generator. We may consider the indications 

 of the thermal ammeters i x and i 2 when 



(i.) C 2 is brought from a small value, through the point 

 of resonance (L 2 C 2 = L 1 C 1 )L, to a large value ; and 

 (ii.) when the value of C 2 is thereupon gradually de- 

 creased through resonance to the first small value. 



The relations between % Y and a> 2 2 and i 2 and a> 2 2 thus ob- 

 tained are shown in figs. 2 and 3, where the arrows indicate 

 the paths followed. Further, in these two diagrams the total 

 system is found to vibrate for conditions represented by 

 EFB in one of the two modes of vibration, i. e. with the 

 higher one of the two coupling frequencies, while for con- 

 ditions represented by DCA the system vibrates w T ith the 

 lower coupling frequency. Hence at the points B and A 

 discontinuities occur in the modes of vibration, resulting in 

 a discontinuity both in frequency and amplitudes of the 

 currents. But, further, it is also seen from these graphs that 

 the system has the tendency to go on oscillating as long as 



