# Ex_8_1
# given data :
Beta=100.;# unitless
Rc=2.;# kohm
Rb=100.;# kohm
Vcc=10.;# V
VBE=0.7;# V
# Part (a)
IB=(Vcc-VBE)/(Beta*Rc+Rc+Rb);# mA
print"IB(mA)",IB
IC=Beta*IB;# mA
print"IC(mA)",IC
VCE=Vcc-(IB+IC)*Rc;# V
print"VCE(V)",VCE
# Part (b)
VCE=7;# V
ICB=(Vcc-VCE)/Rc;# mA(ICB=IC+IB)
IB=ICB/(1+Beta);# mA
IC=ICB*Beta;# mA
Rb=(Vcc-VBE-Rc*ICB)/IB;# kohm
print"Value of Rb(kohm)",Rb
# Ex_8_4
# given data :
Beta=50.;# unitless
VBE=0.7;# V
VCC=22.5;# V
Rc=5.6;# kohm
VCE=12.;# V
IC=1.5;# mA
S=3.;# Stability factor(S<=3)
Rec=(VCC-VCE)/IC;# kohm(Rec=Re+Rc)
Re=Rec-Rc;# kohm
RbBYRe=(S-1)/(1-S/(1+Beta))
Rb=RbBYRe*Re;# kohm
IB=IC/Beta;# mA
V=IB*Rb+VBE+(IB/1000+IC)*Re;# V
R1=Rb*VCC/V;# kohm
R2=R1*V/(VCC-V);# kohm
print"Value of Re(kohm)",Re
print"Value of R1(kohm)",R1
print"Value of R2(kohm)",R2
# Answer in the book is wrong for R1.
# Ex_8_5
# given data :
VCC=20.;# V
Rc=1.5;# kohm
VCE=8.;# V
IC=4.;# mA
Beta=50.;# unitless\
VBE=0.2;# V
print"Part (a)"
S=12.;# Stability factor
IB=IC/Beta;# mA
Re=(VCC-VCE-IC*Rc)/(IB+IC);# kohm
RbBYRe=(S-1)/(1-S/(1+Beta))
Rb=RbBYRe*Re;# kohm
IE=IB+IC;# mA
VBN=VBE+IE*Re;# V
V=VBN+IB*Rb;# V
R1=Rb*VCC/V;# kohm
IR1=(VCC-VBN)/R1;# mA
IR2=IR1-IB;# mA
R2=VBN/IR2;# kohm
print"Value of R1(kohm)",R1
print"Value of R2(kohm)",R2
print"Value of Re(kohm)",Re
print"Part (b)"
S=3.;# Stability factor
IB=IC/Beta;# mA
Re=(VCC-VCE-IC*Rc)/(IB+IC);# kohm
RbBYRe=(S-1)/(1-S/(1+Beta))
Rb=RbBYRe*Re;# kohm
IE=IB+IC;# mA
VBN=VBE+IE*Re;# V
V=VBN+IB*Rb;# V
R1=Rb*VCC/V;# kohm
IR1=(VCC-VBN)/R1;# mA
IR2=IR1-IB;# mA
R2=VBN/IR2;# kohm
print"Value of R1(kohm)",R1
print"Value of R2(kohm)",R2
print"Value of Re(kohm)",Re
print"Value of Rb(kohm)",Rb
# Answer in the book is wrong.
# Ex_8_6
# given data :
VBE=0.7;# V
Beta=50.;# unitless
VCE=4.;# V
VCC=12.;# V
Rc=4.3;# kohm
VEE=-6.;# V
IC=1.5;# mA
S=3.;# Stability factor(S<=3)
Rec=(VCC-VCE)/IC;# kohm(Rec=Re+Rc)
Re=Rec-Rc;# kohm
RbBYRe=(S-1)/(1-S/(1+Beta))
Rb=RbBYRe*Re;# kohm
IB=IC/Beta;# mA
V=IB*Rb+VBE+(IB/1000+IC)*Re;# V
R1=Rb*VCC/V;# kohm
R2=R1*V/(VCC-V);# kohm
print"Value of Re(kohm)",Re
print"Value of R1(kohm)",R1
print"Value of R2(kohm)",R2
# Answer in the book is wrong for R1.