r.WUUM TiHE OSCll.L.lTOh'S 



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to the next suciTcdiiiR unit, and tlu-ri-hy controlling tlu- t-ncrny which 

 that unit, in turn, delivers to the next. In case such a unit is made 

 ii)) of a vacuum lube amplilier circuit with its associated i)()wer supply 

 batteries, it will be capable of passing; on to succeeding units a greater 

 amount of energy in a given time than it receives from preceding 

 units. If a transmission unit does not contain some source of energy, 

 it will, in general, deliver less power than it receives. In many cases 

 these units may be arranged so as to form a complicated network. 

 Whenever in such a network, a group of units forms a closed loop, 

 that particular group is said to constitute a regenerative system. 

 If a regenerative s\stem is capable of maintaining a continuous flow 

 of energy around the loop without receiving energy from any unit 



Fig. 1 — Elements of an oscillating system 



of the transmission network external to the loop, the system is said to 

 be oscillatory. 



For the purpose of this discussion let us think of an oscillatory 

 system as made up of three units, the amplifier with its associated 

 power supply source, a fiequency control unit and an energy absorb- 

 ing load unit. The arrangement of these units is as shown in Fig. 1. 

 Now it is quite possible to determine the individual characteristics of 

 the amplifier and of the frequency control units considered separately. 

 The problem is to find the relation between these individual charac- 

 teristics and the characteristics of the system. 



In order that the regenerative circuit shall be in stable equilibrium, 

 there are two conditions which must be met. The first of these is 

 that the increase in power from the point B to the point A, through the 

 amplifier unit, must be exactly equal to the decrease in power from the 



