Page 18 - Semester-IV-Electronics

 The input base current in transistor Q is very small so that emitter
3
current IE of Q is nearly equal to the collector current of Q . Thus,
1 2
the voltage I R remains constant.
1
E
 For signal voltage, from the input point 1 to putput point 3, the

voltage fall is, V BE1 + I R + V BE3 = K volt
1
E

 If in the absence of signal V and V are input and output steady
0
i
voltages and ∆V and ∆V are respectively the variations in input and
i
0
output voltage, respectively, then, V – K = V and (∆V + V) – K =
i 0 i i
(∆V + V ).
0
0
 Thus, ∆V = ∆V , the change in input voltage is transferred to output.
i 0

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