Chapter - 34 : REGULATED POWER SUPPLIES

Ex 34.1 Pg 955

In [1]:
from __future__ import division

VL=100*10**-6#
VS=5#
LR=VL/VS#
print 'LR=%0.2f microV/V'%(LR*10**6)

LR=20.00 microV/V

Ex 34.2 Pg 955

In [2]:
from __future__ import division

LR=1.4*10**-6#
VS=10#
#LR=VL/VS#
VL=LR*VS
print 'VL=%0.2f microV'%(VL*10**6)

VL=14.00 microV

Ex 34.3 Pg 956

In [3]:
from __future__ import division

IL=40*10**-3#
VNL=8#
VFL=7.995#
LR=(VNL-VFL)/IL#
print 'LR=%0.2f microV/mA'%(LR*10**3)

LR=125.00 microV/mA

Ex 34.4 Pg 956

In [6]:
from __future__ import division

VNL=5#
IL=20*10**-3#
LR=10*10**-6#
#LR=(VNL-VFL)/IL#
VFL=VNL-IL*LR#
print 'VFL=%0.2f'%VFL

VFL=5.00

Ex 34.5 Pg 957

In [7]:
from __future__ import division

#e.g 34.5
V0=10#
R=0.00002
VAR=V0*R#
print 'VAR=%0.2f mV'%(VAR*10**3)

VAR=0.20 mV

Ex 34.6 Pg 957

In [8]:
from __future__ import division

#e.g 34.6
vs=30#
rs=240#
vz=12#
rl=500#
vl=vz#
print 'vl=%0.2f V'%vl
Is=(vs-vz)/rs
Vd=Is*rs#
print 'Vd=%0.2f V'%Vd
Iz=Is-(vl/rl)
print 'Iz=%0.2f A'%Iz

vl=12.00 V
Vd=18.00 V
Iz=0.05 A

Ex 34.7 Pg 957

In [9]:
from __future__ import division

Vz=5.1#
rz=10#
Izmin=1*10**-3#
Izmax=15*10**-3#
Rs=600#
Vomin=Vz+Izmin*rz#
print 'Vomin=%0.2f '%Vomin
Vsmin=Izmin*Rs+Vomin#
print 'Vsmin=%0.2f '%Vsmin
Vomax=Vz+Izmax*rz#
print 'Vomax=%0.2f '%Vomax
Vsmax=Izmax*Rs+Vomax#
print 'Vsmax=%0.2f '%Vsmax

Vomin=5.11 
Vsmin=5.71 
Vomax=5.25 
Vsmax=14.25

Ex 34.8 Pg 958

In [10]:
from __future__ import division

Vs=24#
Rs=500#
Vz=12#
Izmin=3*10**-3#
Izmax=90*10**-3#
rz=0#
Is=(Vs-Vz)/Rs#
print 'Is=%0.2f mA'%(Is*10**3)
ILmax=Is-Izmin#
print 'ILmax=%0.2f mA'%(ILmax*10**3)
RLmin=Vz/ILmax#
print 'RLmin=%0.2f ohm'%(RLmin)

Is=24.00 mA
ILmax=21.00 mA
RLmin=571.43 ohm

Ex 34.9 Pg 958

In [11]:
from __future__ import division

Vsmin=22#
Rs=1*10**3#
Vz=10#
RL=2*10**3#
Vsmax=40#
IL=Vz/RL#
print 'IL=%0.2f mA'%(IL*10**3)
Izmax=((Vsmax-Vz)/Rs)-IL#
print 'Izmax=%0.2f mA'%(Izmax*10**3)
Izmin=((Vsmin-Vz)/Rs)-IL#
print 'Izmin=%0.2f mA'%(Izmin*10**3)

IL=5.00 mA
Izmax=25.00 mA
Izmin=7.00 mA

Ex 34.10 Pg 958

In [12]:
from __future__ import division

Vz=10#
Vsmin=13#
Vsmax=16#
ILmin=10*10**-3#
ILmax=85*10**-3#
Izmin=15*10**-3#
Rsmax=(Vsmin-Vz)/(Izmin+ILmax)#
print 'Rsmax=%0.2f ohm'%Rsmax
Izmax=((Vsmax-Vz)/Rsmax)-ILmin#
Pzmax=Izmax*Vz#
print 'Pzmx=%0.2f W'%Pzmax

Rsmax=30.00 ohm
Pzmx=1.90 W

Ex 34.11 Pg 959

In [13]:
from __future__ import division
from math import sqrt
Vsmin=19.5#
Vsmax=22.5#
RL=6*10**3#
Vz=18#
Izmin=2*10**-6#
Pzmax=60*10**-3#
rz=20#
Izmax=sqrt(Pzmax/rz)#
IL=Vz/RL#
ILmax=IL#
ILmin=IL#
Rsmax=(Vsmin-Vz)/(Izmin+ILmax)#
print 'Rsmax=%0.2f ohm'%Rsmax
Rsmin=(Vsmax-Vz)/(Izmax+ILmin)#
print 'Rsmin=%0.2f ohm'%Rsmin

Rsmax=499.67 ohm
Rsmin=77.89 ohm

Ex 34.12 Pg 959

In [14]:
from __future__ import division

Vsmin=8#
Vsmax=12#
Rs=2.2*10**3#
Vz=5#
RL=10*10**3#
Ismin=(Vsmin-Vz)/Rs#
Ismax=(Vsmax-Vz)/Rs#
IL=Vz/RL#
Izmin=Ismin-IL#
print 'Izmin=%0.2f mA'%(Izmin*10**3)
Izmax=Ismax-IL#
print 'Izmax=%0.2f mA'%(Izmax*10**3)

Izmin=0.86 mA
Izmax=2.68 mA

Ex 34.13 Pg 960

In [15]:
from __future__ import division

VL=5#
Vz=5#
IL=20*10**-3#
Pzmax=500*10**-3#
Vsmax=15#
Vsmin=9#
Izmax=Pzmax/Vz#
Ismax=IL+Izmax#
Vz=VL#
Rsmin=(Vsmax-Vz)/(Izmax+IL)#
print 'Rsmin=%0.2f ohm'%Rsmin
ILmax=IL#
Iz=((Vsmin-Vz)/Rsmin)-ILmax#
print 'Iz=%0.2f mA'%(Iz*10**3)

Rsmin=83.33 ohm
Iz=28.00 mA

Ex 34.14 Pg 960

In [16]:
from __future__ import division

Vz=10#
Vbe=0.7#
RL=100#
Vs=15#
B=100#
Rs=33#
VL=Vz+Vbe#
IL=VL/RL#
Is=(Vs-VL)/Rs#
Ic=Is-IL#
Ib=Ic/B#
print 'Ib=%0.2f microA'%(Ib*10**6)

Ib=233.03 microA

Ex 34.15 Pg 960

In [17]:
from __future__ import division

Vs=15#
Vz=8.3#
B=100#
R=1.8*10**3#
RL=2*10**3#
Vbe=0.7#
VL=Vz-Vbe#
Vce=Vs-VL#
IR=(Vs-Vz)/R#
IL=VL/RL#
IB=IL/B#
print 'IB=%0.2f microA'%(IB*10**6) #In question beta is 100 but while solving it is taken as 50 which is wrong
Iz=IR-IB#
print 'Iz=%0.2f mA'%(Iz*10**3)

IB=38.00 microA
Iz=3.68 mA

Ex 34.16 Pg 961

In [18]:
from __future__ import division

ILmin=0#
ILmax=2#
VL=12#
Vsmin=15#
Vsmax=20#
B=100#
VBE=0.5#
Vz=12.5#
Izmin=1*10**-3#
IBmax=ILmax/B#
IR=IBmax+Izmin
Rmax=(Vsmin-Vz)/IR#
print 'Rmax=%0.2f ohm'%Rmax
Izmax=(Vsmax-Vz)/Rmax#
print 'Izmax=%0.2f mA'%(Izmax*10**3)
Pzmax=Vz*Izmax#
print 'Pzmax=%0.2f W'%Pzmax
PRmax=(Vsmax-Vz)*Izmax#
print 'PRmax=%0.2f W'%PRmax
VCEmax=Vsmax-VL#
print 'VCEmax=%0.2f V'%VCEmax
PDmax=VCEmax*ILmax#
print 'PDmax=%0.2f W'%PDmax

Rmax=119.05 ohm
Izmax=63.00 mA
Pzmax=0.79 W
PRmax=0.47 W
VCEmax=8.00 V
PDmax=16.00 W

Ex 34.17 Pg 961

In [19]:
from __future__ import division

VL=12#
IL=200*10**-3#
Vs=30#
Rs=10#
B1=150#
Ic1=10*10**-3#
VBE1=0.7#
B2=100#
VBE2=0.7#
Vz=6#
Rz=10#
Iz=20*10**-3#
ID=10*10**-3#
I1=10*10**-3#
RD=(VL-Vz)/ID#
print 'RD=%0.2f ohm'%RD
#a=R1/R2#
a=(VL/(Vz+VBE2))-1#
Ic2=Ic1#
IB2=Ic2/B2#
V2=Vz+VBE2#
Vz=12#
R1=(Vz-V2)/I1#
print 'R1=%0.2f ohm'%R1
R2=R1/a#
print 'R2=%0.2f ohm'%R2
hfe1=B1#
IB1=(IL+I1+ID)/hfe1#
I=IB1+Ic2#
R3=(Vs-(VBE1+VL))/I#
print 'R3=%0.2f kohm'%(R3*10**-3)

RD=600.00 ohm
R1=530.00 ohm
R2=670.00 ohm
R3=1.51 kohm

Ex 34.18 Pg 961

In [20]:
from __future__ import division

Vs=25#
Vz=15#
RL=1*10**3#
VBE2=0.7#
Vout=(Vz/2)+VBE2#
print 'Vout=%0.2f V'%Vout
IL=Vout/RL#
IE1=IL#
print 'IE1=%0.2f mA'%(IE1*10**3)
Vce1=Vs-Vout#
P1=Vce1*IE1#
print 'P1=%0.2f mW'%(P1*10**3)

Vout=8.20 V
IE1=8.20 mA
P1=137.76 mW

Ex 34.19 Pg 961

In [21]:
from __future__ import division

IADJ=100*10**-6#
Vin=35#
VREF=1.25#
R2=0#
R1=220#
Voutmin=VREF*(1+(R2/R1))+IADJ*R2#
print 'Voutmin=%0.2f V'%Voutmin
R2=5000#
Voutmax=VREF*(1+(R2/R1))+IADJ*R2#
print 'Voutmax=%0.2f V'%Voutmax

Voutmin=1.25 V
Voutmax=30.16 V

Ex 34.20 Pg 962

In [22]:
from __future__ import division

R1=220#
R2=1500#
Vo=1.25*(1+(R2/R1))#
print 'Vo=%0.2f V'%Vo #answer given in book is wrong

Vo=9.77 V

Ex 34.21 Pg 962

In [23]:
from __future__ import division

R1=240#
R2=2.4*10**3#
Vo=1.25*(1+(R2/R1))#
print 'Vo=%0.2f V'%Vo

Vo=13.75 V