{
"metadata": {
"name": ""
},
"nbformat": 3,
"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chapter 3:Transistor Amplifiers"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"example 3.1, page No.117"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Gain Impedence and ac load\n",
"import math\n",
"#Variable declaration\n",
"ib=10.0 #in uA\n",
"ic=1.0 #in mA\n",
"ic=ic*10**3 #in uA\n",
"vi=0.02 #in Volt\n",
"RC=5.0 #in kohm\n",
"RL=10.0 #in kohm\n",
"\n",
"#Calculations\n",
"\n",
"#Part (i)\n",
"Ai=-ic/ib #unitless\n",
"Beta=Ai #unitless\n",
"\n",
"#Part (ii)\n",
"Rie=vi/(ib*10**-6) #in Ohm\n",
"\n",
"#Part (iii)\n",
"Rac=RC*RL/(RC+RL) #in kohm\n",
"\n",
"#Part (iv)\n",
"Av=-Rac*10**3*Beta/Rie #unitless\n",
"\n",
"#Part (v)\n",
"PowerGain=Av*Ai #unitless\n",
"\n",
"#Result\n",
"print(\"(i)\\tCurrent gain : %.2f\"%Ai)\n",
"print(\"(ii)\\tInput impedence in kohm :%.0f\"%(Rie*10**-3))\n",
"print(\"(iii)\\tAC load in kohm : %.1f\"%Rac)\n",
"print(\"(iv)\\tVoltage gain :%.3f\"%Av)\n",
"print(\"(v)\\tPower Gain is : %.3f\"%PowerGain)\n",
"#Note : Ans of Av and Power gain is wrong in the book."
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"(i)\tCurrent gain : -100.00\n",
"(ii)\tInput impedence in kohm :2\n",
"(iii)\tAC load in kohm : 3.3\n",
"(iv)\tVoltage gain :166.667\n",
"(v)\tPower Gain is : -16666.667\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"example 3.2, page No.125"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Gain input and output impedence\n",
"import math\n",
"\n",
"#Varible declaration\n",
"RL=10.0 #in kohm\n",
"RS=1.0 #in kohm\n",
"hie=1.1 #in kOhm\n",
"hre=2.5*10**-4 #unitless\n",
"hfe=50.0 #unitless\n",
"hoe=25.0 #in u mho\n",
"\n",
"#Calculations\n",
"Aie=-hfe/(1+hoe*10**-6*RL*10**3)#unitless\n",
"Zie=hie+hre*Aie*RL #in kOhm\n",
"Zie=math.ceil(Zie)\n",
"Ave=Aie*RL/Zie #unitless\n",
"Avs_e=Ave*Zie/(Zie+RS)\n",
"deltah=hoe*10**-6*hie*10**3-hfe*hre\n",
"Zoe=(hie*10**3+RS*10**3)/(hoe*10**-6*RS*10**3+deltah)\n",
"Ais_e=Aie*RS/(Zie+RS)\n",
"Ape=Ave*Aie\n",
"Aps_e=Avs_e*Ais_e\n",
"\n",
"#Result\n",
"print(\"Current gain :%.0f \"%Aie)\n",
"print(\"\\nCurrent gain with source resistance : %.0f\"%Ais_e)\n",
"print(\"\\nVoltage gain : %.0f\"%Ave)\n",
"print(\"\\nVoltage gain with source resistance : %.0f\"%Avs_e)\n",
"print(\"\\nPower gain :%.0f \"%Ape)\n",
"print(\"\\nPower gain with source resistance :%.0f \"%Aps_e)\n",
"print(\"\\nInput impedence in kohm :%.1f\"%Zie)\n",
"print(\"\\nOutput impedence in kohm :%.1f\"%(Zoe/10**3))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Current gain :-40 \n",
"\n",
"Current gain with source resistance : -20\n",
"\n",
"Voltage gain : -400\n",
"\n",
"Voltage gain with source resistance : -200\n",
"\n",
"Power gain :16000 \n",
"\n",
"Power gain with source resistance :4000 \n",
"\n",
"Input impedence in kohm :1.0\n",
"\n",
"Output impedence in kohm :52.5\n"
]
}
],
"prompt_number": 16
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"example 3.3, Page No. 126"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Input Output impedence and output voltage\n",
"import math\n",
"#Variable declaration\n",
"InputVoltage=1.0 #in mV\n",
"RL=5.6 #in kohm\n",
"RS=600.0 #in ohm\n",
"hre=6.5*10**-4 #unitless\n",
"hie=1.7 #in kOhm\n",
"hfe=125.0 #unitless\n",
"hoe=80.0 #in uA/V\n",
"\n",
"#Calculations\n",
"deltah=hoe*10**-6*hie*10**3-hfe*hre\n",
"Zie=(hie*10**3+RL*10**3*deltah)/(1+hoe*10**-6*RL*10**3)\n",
"Zoe=(hie*10**3+RS)/(hoe*10**-6*RS+deltah)\n",
"Ave=-(hfe*RL*10**3)/(hie*10**3+RL*10**3*deltah)\n",
"Avs_e=Ave*Zie/(Zie+RS)\n",
"OutputVoltage=Avs_e*InputVoltage\n",
"\n",
"#Result\n",
"print(\"Input impedence in kohm :%.3f\"%(Zie/1000))\n",
"print(\"Output impedence in kohm :%.3f\"%(Zoe/10**3))\n",
"print(\"Voltage gain : %.3f\"%Ave)\n",
"print(\"Voltage gain with source resistance : %.3f\"%Avs_e)\n",
"print(\"Output Voltage in mV :%.3f \"%OutputVoltage)\n",
"#Note : Answers are wrong in the book."
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Input impedence in kohm :1.386\n",
"Output impedence in kohm :22.384\n",
"Voltage gain : -348.849\n",
"Voltage gain with source resistance : -243.444\n",
"Output Voltage in mV :-243.444 \n"
]
}
],
"prompt_number": 2
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"example 3.4, Page no.129"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Net voltage gain in dB\n",
"import math\n",
"#variable declaration\n",
"A1=100.0 #unitless\n",
"A2=200.0 #unitless\n",
"A3=400.0 #unitless\n",
"\n",
"#calculations\n",
"A1=20*math.log10(A1) #in dB\n",
"A2=20*math.log10(A2) #in dB\n",
"A3=20*math.log10(A3) #in dB\n",
"NetVoltageGain=A1+A2+A3 #in dB\n",
"\n",
"#Result\n",
"print(\"Net Voltage Gain in decibels :%.3f\"%NetVoltageGain)\n",
"#Note : Answer in the book is wrong."
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Net Voltage Gain in decibels :138.062\n"
]
}
],
"prompt_number": 3
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"example 3.5, Page No.129"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Bandwidth and cut off frequencies \n",
"import math\n",
"#Variable declaration\n",
"MaxGain=1000.0 #unitless(at 2kHz)\n",
"f1=50.0 #in Hz\n",
"f2=10.0 #in KHz\n",
"\n",
"#Result\n",
"print(\"Bandwidth is from %.0f Hz to %.0f kHz\"%(f1,f2))\n",
"print(\"Lower cutoff frequency %.0f Hz\"%f1)\n",
"print(\"Upper cutoff frequency %.0f kHz\"%f2)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Bandwidth is from 50 Hz to 10 kHz\n",
"Lower cutoff frequency 50 Hz\n",
"Upper cutoff frequency 10 kHz\n"
]
}
],
"prompt_number": 22
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"example 3.6, Page No.137"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Overall voltage gain\n",
"import math\n",
"#Variable declaration\n",
"RC=10.0 #in kohm\n",
"hfe=330.0 #unitless\n",
"hie=4.5 #in kOhm\n",
"\n",
"#Calculation\n",
"#RS<<hie\n",
"AVM=hfe*RC*10**3/(hie*10**3+RC*10**3)\n",
"AVM1=AVM #Gain of 1st stage\n",
"AVM2=AVM #Gain of 2nd stage\n",
"AVM3=hfe*RC*10**3/(hie*10**3) #unitless(//Gain of 3rd stage)\n",
"OverallGain=AVM1*AVM2*AVM3 #unitless\n",
"\n",
"#Result\n",
"print(\"Gain in mid frequeny range : %.1f\"%AVM)\n",
"print(\"This is the gain of 1st and 2nd stage.\")\n",
"print(\"Overall Voltage gain for mid frequency range : %.1f * 10^7\"%(OverallGain/10**7))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Gain in mid frequeny range : 227.6\n",
"This is the gain of 1st and 2nd stage.\n",
"Overall Voltage gain for mid frequency range : 3.8 * 10^7\n"
]
}
],
"prompt_number": 27
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"example 3.7, Page No.138"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Couopling capacitor\n",
"import math\n",
"#variable declaration\n",
"RC=5.5 #in kohm\n",
"hfe=330.0 #unitless\n",
"hie=4.5 #in kohm\n",
"f1=30.0 #in Hz\n",
"\n",
"#Calculation\n",
"#Formula : f1=1/(2*%pi*C*(hie+RC))\n",
"C=1/(2*math.pi*f1*(hie*10**3+RC*10**3))\n",
"\n",
"#Result\n",
"print(\"Value of coupling capacitor in micro farad : %.2f\"%(C*10**6))\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Value of coupling capacitor in micro farad : 0.53\n"
]
}
],
"prompt_number": 29
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"example 3.8, Page No.142"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Voltage gain\n",
"import math\n",
"#Variable declaration\n",
"RC=10.0 #in kohm\n",
"Rin=1.0 #in kohm\n",
"Beta=100.0 #unitless\n",
"RL=100.0 #in ohm\n",
"\n",
"#Calculation\n",
"RCdash=RC*10**3*RL/(RC*10**3+RL)\n",
"VoltageGain=Beta*RCdash/(Rin*10**3)\n",
"\n",
"#Result\n",
"print(\"Voltage Gain :%.2f \"%VoltageGain)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Voltage Gain :9.90 \n"
]
}
],
"prompt_number": 31
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"example 3.9, Page No. 142"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Inductance of primary and secondary\n",
"import math\n",
"\n",
"#variable declaration\n",
"Rout=10.0 #in kohm\n",
"Rin=2.5 #in kohm\n",
"f=200.0 #in Hz\n",
"\n",
"#Calculations\n",
"\n",
"#Formula : Rout=omega*Lp=2*%pi*f*Lp\n",
"Lp=Rout*10**3/(2*math.pi*f) #in H\n",
"#Formula : Rin=omega*Ls=2*%pi*f*Ls\n",
"Ls=Rin*10**3/(2*math.pi*f) #in H\n",
"\n",
"#Result\n",
"print(\"Inductance of primary in Henry : %.0f\"%Lp)\n",
"print(\"Inductance of seondary in Henry : %.0f\"%Ls)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Inductance of primary in Henry : 8\n",
"Inductance of seondary in Henry : 2\n"
]
}
],
"prompt_number": 33
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"example 3.10, Page No.142"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Turn ratio of transformer\n",
"import math\n",
"#variable declaration\n",
"ZL=10.0 #in ohm\n",
"ZP=1000.0 #in ohm\n",
"\n",
"#For max power : ZP=n^2*ZL\n",
"n=math.sqrt(ZP/ZL) #turn ratio\n",
"\n",
"#Result\n",
"print(\"Turn ratio : %.0f\"%n)\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Turn ratio : 10\n"
]
}
],
"prompt_number": 38
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"example 3.11, Page No.149 "
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Collector eficieny and power rating\n",
"import math\n",
"#Variable declaration\n",
"Po_dc=10.0 #in watt\n",
"Po_ac=3.5 #in watt\n",
"\n",
"#calculation\n",
"ETAcollector=Po_ac/Po_dc #unitless\n",
"ETAcollector=ETAcollector*100 #collector efficiency in %\n",
"\n",
"#Result\n",
"print(\"Collector Efficiency : %.0f%%\"%ETAcollector)\n",
"print(\"\\nZero signal condition represents maximum power loss.\")\n",
"print(\"Therefore, all the 10 W power is dissipated by it. Hence Powe Rating of transistor in Watt : %.0f\"%Po_dc)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Collector Efficiency : 35%\n",
"\n",
"Zero signal condition represents maximum power loss.\n",
"Therefore, all the 10 W power is dissipated by it. Hence Powe Rating of transistor in Watt : 10\n"
]
}
],
"prompt_number": 42
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"example 3.12, Page No.149"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Power and eficiency\n",
"import math\n",
"#variable declaration\n",
"VCC=20.0 #in volt\n",
"RC=20.0 #in ohm\n",
"VCEQ=10.0 #in volt\n",
"ICQ=500.0 #in mA\n",
"\n",
"#calculations\n",
"#part (i) :\n",
"Pin_dc=VCC*ICQ*10**-3 #in watt\n",
"\n",
"#part (ii) :\n",
"PRc_dc=ICQ**2*10**-6*RC #in watt\n",
"\n",
"#part (iii) :\n",
"Io=250 #in mA(maximum value of output ac current)\n",
"Irms=Io/math.sqrt(2) #in mA\n",
"Po_ac=Irms**2*10**-6*RC #in watt\n",
"\n",
"#part (iv) :\n",
"Ptr_dc=Pin_dc-PRc_dc #in watt\n",
"\n",
"#part (v) :\n",
"PC_dc=Pin_dc-PRc_dc-Po_ac #in watt\n",
"\n",
"#part (vi) :\n",
"ETAoverall=Po_ac*100/Pin_dc #Overall Efficiency (in %)\n",
"\n",
"#part (vii) :\n",
"ETAcollector=Po_ac*100/PRc_dc#Collector Efficiency (in %)\n",
"\n",
"\n",
"#Result\n",
"print(\"(i)\\nTotal dc power taken by the circuit in Watt : %.0f\"%Pin_dc)\n",
"print(\"\\n(ii)\\ndc power dissipated by the collector load in Watt : %.0f\"%PRc_dc)\n",
"print(\"\\n(iii)\\nPower developed across the load in Watt :%.3f \"%Po_ac)\n",
"print(\"\\n((iv)\\ndc power dissipated by the collector load in Watt :%.0f \"%Ptr_dc)\n",
"print(\"\\n(v)\\ndc power dissipated by the collector load in Watt : %.3f\"%PC_dc)\n",
"print(\"\\n(vi)\\nOverall Efficiency :%.3f%%\"%ETAoverall)\n",
"print(\"\\n(vii)\\nCollector Efficiency :%.2f%%\"%ETAcollector)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"(i)\n",
"Total dc power taken by the circuit in Watt : 10\n",
"\n",
"(ii)\n",
"dc power dissipated by the collector load in Watt : 5\n",
"\n",
"(iii)\n",
"Power developed across the load in Watt :0.625 \n",
"\n",
"((iv)\n",
"dc power dissipated by the collector load in Watt :5 \n",
"\n",
"(v)\n",
"dc power dissipated by the collector load in Watt : 4.375\n",
"\n",
"(vi)\n",
"Overall Efficiency :6.250%\n",
"\n",
"(vii)\n",
"Collector Efficiency :12.50%\n"
]
}
],
"prompt_number": 5
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"example 3.13, Page No.151"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Maximum ac power output\n",
"import math\n",
"#variable declaration\n",
"n=10.0 #turn ratio\n",
"RL=100.0 #in ohm\n",
"ICQ=100.0 #in mA\n",
"\n",
"#calculations\n",
"RLdash=n**2*RL \n",
"MaxPowerOut=(ICQ*10**-3)**2*RLdash/2\n",
"\n",
"#result\n",
"print(\"Maximum Power output in watt : %.0f\"%MaxPowerOut)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Maximum Power output in watt : 50\n"
]
}
],
"prompt_number": 47
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"example 3.14, Page No.152"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Maximum permissible power dissipation\n",
"import math\n",
"#Part (i) : without heat sink\n",
"\n",
"#variable declaration\n",
"ThetaMax=90.0 #in degree C\n",
"Theta_o=30.0 #in degree C\n",
"R=300.0 #in degree C/W\n",
"\n",
"#calculation\n",
"Pr=(ThetaMax-Theta_o)/R #in watt\n",
"\n",
"#Result\n",
"print(\"Without heat sink, Maximum permissible power dissipatio in watt :%.1f\"%Pr)\n",
"\n",
"#Part (ii) : with heat sink\n",
"\n",
"#variable declaration\n",
"ThetaMax=90.0 #in degree C\n",
"Theta_o=30.0 #in degree C\n",
"R=60.0 #in degree C/W\n",
"\n",
"#calculation\n",
"Pr=(ThetaMax-Theta_o)/R #in watt\n",
"\n",
"#Result\n",
"print(\"With heat sink, Maximum permissible power dissipatio in watt :%.0f\"%Pr)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Without heat sink, Maximum permissible power dissipatio in watt :0.2\n",
"With heat sink, Maximum permissible power dissipatio in watt :1\n"
]
}
],
"prompt_number": 51
}
],
"metadata": {}
}
]
}