# Chapter 12:Modulating,Demodulating and frequency Changing with the multiplier¶

### Example 12.1 Page No 332¶

In [4]:
#Given
#(a)
V=10.0
x1=10              #Polarity combination of voltages
y1=10              #V
#(b)
x2=-10             #V, 2nd combination
y2=10              #V
#(c)
x3=10              #V
y3=-10             #V
#(d)
x4=-10             #V
y4=-10             #V

#Calculation
Vo1=x1*y1/V
Vo2=x2*y2/V
Vo3=x3*y3/V
Vo4=x4*y4/V

#Result
print"The values of Vo are",Vo1,"V ,",Vo2,"V ,",Vo3,"V ,",Vo4,"V"

The values of Vo are 10.0 V , -10.0 V , -10.0 V , 10.0 V


### Example 12.2 Page No 334¶

In [5]:
#Given
Ei1=10           #V
Ei2=-10          #V

#Calculation
Vo1=Ei1**2/Ei1
Vo2=Ei2**2/Ei1

#Reult
print"(a)The value of Vo is",Vo1,"V"
print"(b)The value of Vo is",Vo2,"V"

(a)The value of Vo is 10 V
(b)The value of Vo is 10 V


### Example 12.4 Page No 336¶

In [6]:
#Given
Ei1=10          #V
f1=1            #KHz
Ei2=2           #V
f1=2.5          #KHz

#Calculation
dcvalue=Ei1**2/20.0
pac=Ei1**2/20.0

#(b)
dcvalue_=Ei2**2/20.0
pac_=Ei2**2/20.0

#Result
print"(a)The DC and AC output voltage are",dcvalue,"V,",pac,"V at 2 KHz"
print"(b)The DC and AC output voltage are",dcvalue_,"V,",pac_,"V at 5 KHz"

(a)The DC and AC output voltage are 5.0 V, 5.0 V at 2 KHz
(b)The DC and AC output voltage are 0.2 V, 0.2 V at 5 KHz


### Example 12.5 Page No 339¶

In [1]:
#Given
Exp=5         #V
Eyp=5         #V
Vodc=1.25     #DC component of Vo

#calculation
import math
theta=math.acos(20*Vodc/(Exp*Eyp))

#Result
print"The angle is",theta,"degree"

The angle is 0.0 degree


### Example 12.6 Page No 339¶

In [2]:
#Given
Vo=0          #AVerage value of DC component

#calculation
import math
theta=math.acos(Vo)

#Result
print"The angle  is",round(theta*180/3.14,0),"degree"

The angle  is 90.0 degree


### Example 12.7 Page No 339¶

In [16]:
#Given
theta1=30            #degree
theta2=45            #degree
theta3=60            #degree
theta4=0             #Degree from example 12.5
theta5=90            #Degree from example 12.6

#Calculation
import math
Vodc1=math.cos(theta1*3.14/180.0)
Vodc2=math.cos(theta2*3.14/180.0)
Vodc3=math.cos(theta3*3.14/180.0)
Vodc4=math.cos(theta4*3.14/180.0)
Vodc5=math.cos(theta5*3.14/180.0)

#Result
print"The Output Dc voltages are",round(Vodc1,3),"V ,",round(Vodc2,3),"V ,",round(Vodc3,3),"V ,",round(Vodc4,3),"V ,",round(Vodc5,3),"V ,"

The Output Dc voltages are 0.866 V , 0.707 V , 0.5 V , 1.0 V , 0.001 V ,


### Example 12.8 Page No 340¶

In [3]:
#GIven
theta1=90             #degree
theta2=120            #degree
theta3=135            #degree
theta4=150            #degree
theta5=180            #degree

#Calculation
import math
Vodc1=math.cos(theta1*3.14/180.0)
Vodc2=math.cos(theta2)
Vodc3=math.cos(theta3)
Vodc4=math.cos(theta4)
Vodc5=math.cos(theta5)

#Result
print"The Voltages are",round(Vodc1,3),"V ,",round(Vodc2,3),"V ",round(Vodc3,3),"V ",round(Vodc4,3),"V ",round(Vodc5,3),"V "

The Voltages are 0.001 V , 0.814 V  -0.996 V  0.699 V  -0.598 V


### Example 12.10 Page No 349¶

In [27]:
#Given
Ecp=5             #V, Voltage
fc=10000          #Hz frequency
Em=5              #V  peak voltage
fm=1000           #Hz  frequency

#Calculation
Vc=Em*Ecp/(10.0)      #The carrier term peak voltage
Vp=Vc                  #product term Peak voltage
Vs=Em*Ecp/(20.0)        #The side term peak voltagec

#Result
print"The carrier term peak voltage is",Vc,"V"
print"The product term peak voltage is",Vp,"V"
print"The side term peak voltage is",Vs,"V"

The carrier term peak voltage is 2.5 V
The product term peak voltage is 2.5 V
The side term peak voltage is 1.25 V