Electronic Circuit Analysis

Power Amplifiers
161
I max
t
Ie
I
m~m~~~~~~~~ __ ~
V mm
v c
v
1m'.
v
Fig. 4.17 Transfercurve
where Bo and B\ are constants in the expression
ic = Ic + Bo + B\ Cos eot + B2 Cos 2eot + .....
Expression for instantaneous total current.
If distortion components are negligible,
lv
Tl= 2 m
V I
Ce
C
m
x 100%
Maximum Value of (Tl)
In the case of series fed amplifiers, the supply voltage V cc is equal to V max'
coupled amplifier V cc is equal to the quiescent voltage V c'
Under ideal conditions,
Ic= 1m
and
V =
m
V -V.
max mm
2
In the transfonner
Vm.Im
Tl = 50 V. I
cc c
50X(V max ~ Vmin }Ic
Vccl c
For series fed amplifier, V max = V cc
:. Tl for series fed amplifiers