# Chapter 34 , Time Base Circuits¶

## Example 34.1, Page Number 883¶

In [16]:
import math

#Variables

R = 100.0 * 10**3                                #Resistance (in ohm)
C = 0.4 * 10**-6                                 #Capacitance (in Farad)
n = 0.57                                         #Ratio of peak-peak voltage to the supply voltage

#Calculation

f = 1 / (2.3 * R * C * math.log10(1/(1-n)))      #Frequency (in Hertz)

#Result

print "Frequency of sweep is ",round(f,2)," Hz."

#Slight variation due to higher precision.

Frequency of sweep is  29.66  Hz.


## Example 34.2 , Page Number 883¶

In [17]:
import math

#Variables

n = 0.62                                     #Ratio of peak-peak voltage to the supply voltage
R = 5.0 * 10**3                              #Resistance (in ohm)
C = 0.05 * 10**-6                            #Capacitor (in Farad)

#Calculation

T = 2.3 * R * C * math.log10(1/(1-n))        #Time period of oscillation (in seconds)
f = 1/T                                      #Frequency of oscillation (in Hertz)
f1 = 50.0                                    #New frequency (in Hertz)
T1 = 1/f1                                    #New time period of oscillation (in seconds)
R1 = T1 / (2.3 * C * math.log10(1/(1-n)))    #New Resistance (in ohm)
f2 = 50.0                                    #Another new frequency (in Hertz)
C2 = 0.5 * 10**-6                            #Capacitance (in Farad)
T2 = 1/f2                                    #Another new time period (in seconds)
R2 = T2 / (2.3 * C2 * math.log10(1/(1-n)))   #New Resistance (in ohm)

#Result

print "The time period and frequency of oscillation in case 1 is ",round(T * 10**3,2)," ms and ",round(f)," Hz."
print "New value of R is ",round(R1 * 10**-3)," kilo-ohm."
print "Value of R with C is 0.5 micro-Farad is ",round(R2 * 10**-3,1)," kilo-ohm."

The time period and frequency of oscillation in case 1 is  0.24  ms and  4139.0  Hz.
New value of R is  414.0  kilo-ohm.
Value of R with C is 0.5 micro-Farad is  41.4  kilo-ohm.