# Chapter - 25 : LARGE SIGNAL OR POWER AMPLIFIERS¶

## Ex 25.1 Pg 734¶

In [2]:
from __future__ import division

VCC=10#
R1=10*10**3#
R2=5*10**3#
RC=1*10**3#
RE=500#
RL=1.5*10**3#
B=100#
VBE=0.7#
VR2=VCC*(R2/(R1+R2))#
IEQ=(VR2-VBE)/RE#
ICQ=IEQ#
VCEQ=VCC-ICQ*(RC+RE)#
rL=(RC*RL)/(RC+RL)#
ICsat=ICQ+(VCEQ/rL)#
print 'ICsat=%0.2f mA'%(ICsat*10**3)
VCEsat=0#
print "VCEsat=%0.2f V"%VCEsat
ICcutoff=0#
print "ICcutoff=", ICcutoff
VCEcutoff=VCEQ+ICQ*rL#
print 'VCEcutoff=%0.2f V'%VCEcutoff

ICsat=8.77 mA
VCEsat=0.00 V
ICcutoff= 0
VCEcutoff=5.26 V


## Ex 25.2 Pg 734¶

In [3]:
from __future__ import division

VCC=20#
R1=10*10**3#
R2=1.8*10**3#
RC=620#
RE=200#
RL=1.2*10**3#
hfe=180#
VB=VCC*(R2/(R1+R2))#
VBE=0.7#
VE=VB-VBE#
IE=VE/RE#
IC=IE#
VCE=VCC-IE*(RC+RE)#
ICQ=IC#
VCEQ=VCE#
rL=(RC*RL)/(RC+RL)#
PP=2*ICQ*rL#
print 'PP=%0.2f V'%PP
PP=2*VCEQ#
print 'PP=%0.2f V'%PP

PP=9.61 V
PP=20.72 V


## Ex 25.3 Pg 735¶

In [4]:
from __future__ import division

re=8#
RC=220#
RE=47#
R1=4.7*10**3#
R2=470#
B=50#
rL=RC#
AV=rL/re#
Ai=B#
Ap=AV*Ai#
print "Ap=%0.2f" %Ap

Ap=1375.00


## Ex 25.4 Pg 736¶

In [6]:
from __future__ import division

Ptrdc=20#
Poac=5#
ne=(Poac/Ptrdc)#
print 'ne=%0.2f %%'%(ne*100)
print "power rating of transistor=20W"#

ne=25.00 %
power rating of transistor=20W


## Ex 25.5 Pg 737¶

In [7]:
from __future__ import division

pcdc=10#
nc=0.32#
poac=pcdc*nc/(1-nc)#
print 'poac=%0.2f W'%poac

poac=4.71 W


## Ex 25.6 Pg 738¶

In [8]:
from __future__ import division

nc=0.5#
VCC=24#
Poac=3.5#
Ptrdc=Poac/nc#
print 'Ptrdc=%0.2f W'%Ptrdc
Pcdc=Ptrdc-Poac#
print 'Pcdc=%0.2f W'%Pcdc

Ptrdc=7.00 W
Pcdc=3.50 W


## Ex 25.7 Pg 739¶

In [12]:
from __future__ import division
from math import sqrt
VCC=20#
VCEQ=10#
ICQ=600*10**-3#
RL=16#
IP=300*10**-3#
Pindc=VCC*ICQ#
print 'Pindc=%0.2f W'%Pindc
PRLdc=ICQ**2*RL#
print 'PRLdc=%0.2f W'%PRLdc
I=IP/sqrt(2)#
Poac=I**2*RL#
print 'Poac=%0.2f W'%Poac
Ptrdc=Pindc-PRLdc#
print 'Ptrdc=%0.2f W'%Ptrdc
Pcdc=Ptrdc-Poac#
print 'Pcdc=%0.2f W'%Pcdc
no=Poac/Pindc#
print 'no=%0.2f %%'%(no*100)
no=Poac/Ptrdc#
print 'no=%0.2f %%'%(no*100)

Pindc=12.00 W
PRLdc=5.76 W
Poac=0.72 W
Ptrdc=6.24 W
Pcdc=5.52 W
no=6.00 %
no=11.54 %


## Ex 25.8 Pg 740¶

In [13]:
from __future__ import division

a=15#
RL=8#
RL1=a**2*RL#
print 'RL1=%0.2f kohm'%(RL1*10**-3)

RL1=1.80 kohm


## Ex 25.9 Pg 741¶

In [14]:
from __future__ import division
from math import sqrt
RL=16#
RL1=10*10**3#
a=sqrt(RL1/RL)#
print "a=%0.2f"%a

a=25.00


## Ex 25.10 Pg 742¶

In [15]:
from __future__ import division

RL=8#
a=10#
ICQ=500*10**-3#
RL=a**2*RL#
Poac=(1/2)*ICQ**2*RL#
print 'Poac=%0.2f W'%Poac

Poac=100.00 W


## Ex 25.11 Pg 742¶

In [16]:
from __future__ import division
from math import sqrt
Ptrdc=100*10**-3#
VCC=10#
RL=16#
no=0.5#
Poac=no*Ptrdc#
print 'Poac=%0.2f mW'%(Poac*10**3)
ICQ=2*Poac/VCC#
print 'ICQ=%0.2f A'%ICQ
RL1=VCC/ICQ#
a=sqrt(RL1/RL)#
print "a=%0.1f"%a

Poac=50.00 mW
ICQ=0.01 A
a=7.9


## Ex 25.12 Pg 743¶

In [17]:
from __future__ import division
from math import sqrt
VCC=10#
IP=50*10**-3#
RL=4#
I=IP/sqrt(2)#
Poac=I**2*RL#
print 'Poac=%0.2f mW'%(Poac*10**3)
ICQ=IP#
RL1=VCC/ICQ#
a=sqrt(RL1/RL)#
print "a=%0.2f"%a
V1=VCC#
V2=V1/a#
I2p=V2/RL#
I2=I2p/sqrt(2)#
P=(I2**2)*RL#
print 'P=%0.2f mW'%(P*10**3)

Poac=5.00 mW
a=7.07
P=250.00 mW


## Ex 25.13 Pg 744¶

In [18]:
from __future__ import division

RL=8#
VP=16#
P=(VP**2)/(2*RL)#
print 'P=%0.2f W'%P

P=16.00 W


## Ex 25.14 Pg 745¶

In [21]:
from __future__ import division

no=0.6#
Pcdc=2.5#
#Poac=Pindc*no#
#Pindc=2*Pcdc+Poac#
Pindc=(2*Pcdc)/(1-no)#
print 'Pindc=%0.2f W'%Pindc
Poac=0.6*Pindc#
print 'Poac=%0.2f W'%Poac

Pindc=12.50 W
Poac=7.50 W