Chapter 12 - Power Electronic devices

PageNumber 553 example 1

In [1]:
from math import sqrt
slope1=130
trivol=15##volt
d=0.5##watts
ig=sqrt(d/slope1)
vg=slope1*ig
r=(trivol-vg)/ig
print "source resistance   =   %0.2f"%((r)),"ohm"

source resistance   =   111.87 ohm

PageNumber 553 example 2

In [2]:
from math import exp
latcur=50*10**-3##ampere
durpul=50*10**-6##second
induct=0.5##henry
r=20##ohm
voltag=100##volt
w=induct/r
inpcur=-(voltag/r)*((1)-exp(-durpul/w))
print "current   =   %0.3f"%(abs(inpcur)),"ampere"
print "input current less than required current"

current   =   0.010 ampere
input current less than required current

PageNumber 554 example 3

In [3]:
latcur=4*10**-3##ampere
induct=0.1##henry
voltag=100##volt
durmin=induct*latcur/voltag
print "min duration   =   %0.2e"%((durmin)),"second"

min duration   =   4.00e-06 second

PageNumber 554 example 4

In [4]:
from math import sqrt
slope1=3*10**3
egs=10##volt
d=0.012##watts
ig=sqrt(d/slope1)
vg=slope1*ig
r=(egs-vg)/ig

print "source resistance   =   %0.2f"%((r)),"ohm"##it is not given in the book

source resistance   =   2000.00 ohm

PageNumber 554 example 5

In [5]:
slope1=16
durmax=4*10**-6##second
curmin=500*10**-3##ampere
voltag=15##volt
#(1) resistance
vg=slope1*curmin
r=(voltag-vg)/curmin
#(2)
d=vg*curmin
freque=0.3/(d*durmax)
print "resistance   =   %0.2f"%((r)),"ohm"
print "frequency   =   %0.2f"%((freque)),"hertz"

resistance   =   14.00 ohm
frequency   =   18750.00 hertz

PageNumber 555 example 6

In [6]:
c1=20*10**-12##farad
limcur=16*10**-3##ampere
w=(limcur/c1)*10**-6##convert second to microsecond
print "change of voltage   =   %0.2f"%((w)),"volt per microsecond"

change of voltage   =   800.00 volt per microsecond

PageNumber 555 example 7

In [7]:
from math import sqrt
ratcur=3000##ampere
freque=50##hertz
i=sqrt(ratcur**2/2)
print "current   =   %0.2f"%((i)),"ampere"
i=((ratcur)/sqrt(2))**2/(2*freque)
print "current   =   %0.2f"%((i)),"ampere square second"

current   =   2121.32 ampere
current   =   45000.00 ampere square second

PageNumber 556 example 9

In [8]:
from __future__ import division
from math import log
voltag=30##volt
w=0.51
i1=10*10**-6##ampere
v1=3.5##volt
curen1=10*10**-3##ampere
freque=60##hertz
tridun=50*10**-6##second
pinvol=w*voltag+0.6
r=(voltag-pinvol)/i1
print "max limit resistance   =   %0.2f"%((r)),"ohm"
r=(voltag-v1)/(curen1)
print "min limit resistance   =   %0.2f"%((r)),"ohm"
capac1=0.5*10**-6##farad
r=(1/freque)*(1/(capac1*log(1/(1-w))))
print "resistance   =   %0.2e"%((r)),"ohm"
rb2=10**4/(w*voltag)
rb1=tridun/capac1
print "rb1   =   %0.2f"%((rb1)),"ohm"
print "rb2   =   %0.2f"%((rb2)),"ohm"
print "peak voltage   =   %0.2f"%((pinvol)),"volt"

max limit resistance   =   1410000.00 ohm
min limit resistance   =   2650.00 ohm
resistance   =   4.67e+04 ohm
rb1   =   100.00 ohm
rb2   =   653.59 ohm
peak voltage   =   15.90 volt

PageNumber 557 example 10

In [9]:
re=1*10**3##ohm
i1=5*10**-3##ampere

voltag=re*i1+2
print "voltage   =   %0.2f"%((voltag)),"volt"


print "this voltage makes to off"

voltage   =   7.00 volt
this voltage makes to off