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THE BELL SYSTEM TECHNICAL JOXJRNAL, JULY 1951 



base and ground as shown, for example, in Fig, 18. Since the base floats 

 at a positive potential with respect to ground, this circuit produces a base 

 current of the right sign to decrease the collector current. As the value of 

 the series resistance is decreased to zero, the collector current decreases to 



Fig, 18 — Modification of Fig. 17 to obtain lower collector current. 



Fig. 19 — Modification of Fig. 17 to obtain higher collector current. 



Fig. 20^ A Iwo-stage grounded emitter amplifier which produces approximately 90 db 



power gain is shown on the right and a micro-power audio oscillator is 



shown on the left. 



a value corresponding to zero emitter voltage. A still further decrease in 

 collector current can be obtained by inserting resistance between emitter 

 and ground. 



In order to increase the collector current to values higher than that cor- 

 responding to zero base current, a high resistance path between base and 

 the positive supply voltage may be used as shown in Fig. 19. In this case the 



