Chapter 12 : Display Record And Acquisition Of Data

Example12_1,pg 371

In [5]:
# find excitation voltage and electrode areas

import math
#Variable declaration
E=10**6                #electric field
l=10**-6               #thickness of LCD
V=E*l                  #excitation potential
I=0.1*10**-6           #current
rho=E/I                #crystal resistivity
P=10*10**-6            #power consumption
A=(P/(V*I))            #area of electrodes


#Result
print("excitation potential:")
print("V = %.f V\n"%V)
print("crystal resistivity:")
print("rho = %.f * 10^-12 ohm-cm\n"%(rho*10**-12))
print("area of electrodes:")
print("A = %.f cm^2"%(A))

excitation potential:
V = 1 V

crystal resistivity:
rho = 10 * 10^-12 ohm-cm

area of electrodes:
A = 100 cm^2

Example12_2,pg 383

In [9]:
# find deviation factor

import math
#Variable declaration
fc=10**6                   #carrier frequency
m=0.4                      #modulation index
fs=100.0                   #signal frequency
V=2.0                      #(+/-)2V range


#Calculations
delfc1=m*fc               #frequency deviation for FS(full scale)
#(+/-) 2V corresponds to delfc Hz deviation assuming linear shift, for (+/-)1V
delfc2=delfc1/V          #frequency deviation for (+/-)1V range
sig=(delfc1/fs)          #deviation factor

#Result
print("frequency deviation for FS:")
print("delfc1 = %.f * 10^5 Hz\n"%(delfc1/10**5)) 
print("frequency deviation for given range:")
print("delfc2 = %.f * 10^5 Hz\n"%(delfc2/10**5)) 
print("deviation factor:")
print("sig = %.f * 10^3"%(sig/10**3))

frequency deviation for FS:
delfc1 = 4 * 10^5 Hz

frequency deviation for given range:
delfc2 = 2 * 10^5 Hz

deviation factor:
sig = 4 * 10^3

Example12_3,pg 508

In [20]:
# find wavelength of radiation

import math
#Variable declaration
h=6.625*10**-34                     #planck's const.
e=1.6*10**-19                      #electron charge
c=2.998*10**8                      #speed of light
E=2.02                             #energy gap

#Calculations
lam=((h*c)/E)                      #wavelength of radiation(m/eV)
#1eV=16.017*10^-20J
lam=(lam/(16.017*10**-20))         #conversion in meter

#Result
print("wavelength of radiation:")
print("lam = %.4f * 10^-6 m"%(math.floor(lam*10**10)/10**4))

wavelength of radiation:
lam = 0.6138 * 10^-6 m

Example12_4,pg 508

In [22]:
# thickness of LCD crystal

import math
#Variable declaration
V=1.3                      #excitation voltage
Vgrad=10.0**5              #potential gradient

#Calculations
#10^5 V/mm*thickness in mm=excitation voltage
l=(V/Vgrad)                #thickness of LCD

#Result
print("thickness of LCD:")
print("l = %.f micro-m"%(l*10**6))

thickness of LCD:
l = 13 micro-m

Example12_5,pg 508

In [24]:
# find current density

import math
#Variable declaration
rho=4.0*10**12                  #resistivity of LCD
Vgrad=10.0**6                   #potential gradient

#Calculations
j=(Vgrad/rho)                 #current density

#Result
print("current per cm^2:")
print("j = %.2f micro-A/cm^2"%(j*10**6))

current per cm^2:
j = 0.25 micro-A/cm^2

Example12_6,pg 508

In [25]:
# find magnetic flux in tape

import math
#Variable declaration
f=2*10**3               #frequency of signal
v=1.0                   #velocity of tape
w=0.05*10**-3           #gap width
N=22.0                  #no.of turns on head
V=31*10**-3             #rms voltage o/p

#Calculations
x=(math.pi*f*w)/v
x=x*(math.pi/180)
M=((V*w)/(2*v*N*math.sin(x)))

#Result
print("magnetic flux in tape:")
print("M = %.2f micro-Wb"%(M*10**6))

magnetic flux in tape:
M = 6.42 micro-Wb

Example12_7,pg 509

In [26]:
# channel accomodation

import math
#variable declartion
Br=576.0*10**3               #bit rate conversion
n=8.0                        #resolution requirement per channel
fs=1000.0                    #sampling rate

#Calculations
N=(Br/(fs*3*n))              #no. of channels

#Result
print("no. of channels accomodated:")
print("N = %.f "%N)

no. of channels accomodated:
N = 24

Example12_8,pg 509

In [27]:
# sensor signal transmission

import math
#Variable declaration
Rsmax=1.0*10**3                 #sensor resistance max.
Rsmin=100.0                     #sensor resistance min.
Vs=5.0                          #sensor voltage

#Calculations
Io=(Vs/Rsmax)                   #current source-> ohm's law
Vmin=Rsmin*Io                   #min. output voltage

#Result
print("current source:")
print("Io = %.f mA\n"%(Io*10**3))
print("min. output voltage:")
print("Vmin = %.1f V"%Vmin)

current source:
Io = 5 mA

min. output voltage:
Vmin = 0.5 V

Example12_9,pg 509

In [31]:
# ROM access time

import math
#Variable declaration
#ROM 22*5*7
N=5.0                       #no. of gates in bitand plane
n=22.0                      #no.of inputs
f=913.0                     #refresh rate

#Calculations
#considering column display
ts=(1.0/(N*f*n))              #ROM access time

#Result
print("ROM access time:")
print("ts = %.6f ms"%(ts*1000))

ROM access time:
ts = 0.009957 ms