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{
"metadata": {
"name": "",
"signature": "sha256:1fc7b4e7810aaec71230ef3ddc13645d6efc0b44874bc6bf484268f68693d914"
},
"nbformat": 3,
"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chapter 12:Feedback in amplifiers"
]
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 12.1 Page no.395"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"A=100.0 #Internal Gain\n",
"B=0.1 #Feedback Factor\n",
"\n",
"#Calculation\n",
"Af=A/(1+A*B) # Gain of Feedback Amplifier \n",
"# Result\n",
"print \" The Value of the Gain of Feedback Amplifier is = \",round(Af,2)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" The Value of the Gain of Feedback Amplifier is, = 9.09\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 12.2 Page no. 395"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"Af=100.0 #Voltage Gain\n",
"Vin=.05 #V , Input Signal without Feedaback Gain\n",
"Vi=0.6 #V , Input Signal with Feedaback Gain\n",
"\n",
"#Calculation\n",
"Vo=Af*Vi\n",
"A=Vo/Vin\n",
"B=((A/Af)-1)/A\n",
"#Result\n",
"print \"The Value of the Internal Gain A is, A = \",A\n",
"print \" The Value of the Feedback Gain B is, B = percent \",round(B*100,2)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The Value of the Internal Gain A is, A = 1200.0\n",
" The Value of the Feedback Gain B is, B = percent 0.92\n"
]
}
],
"prompt_number": 2
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 12.3 Page no. 401"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"A=1000 #60dB Voltage Gain\n",
"B=0.005 #Negative Feedback\n",
"dAbyA=-0.12 #dA/A = 12 %\n",
"\n",
"#Calculation\n",
"dAfbyAf=1/(1+A*B)*dAbyA #dAf/Af=1/(1+A*B)*dA/A\n",
"\n",
"# Result\n",
"print \" The change in overall Gain of the Feedback Amplifier is\",dAfbyAf\n",
"print \"Therefore the overall gain of feedback amplifier will be reduce by \",-dAfbyAf*100,\"%\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" The change in overall Gain of the Feedback Amplifier is -0.02\n",
"Therefore the overall gain of feedback amplifier will be reduce by 2.0 %\n"
]
}
],
"prompt_number": 3
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 12.4 Page no. 401"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"Zi=1000.0 #Ohms\n",
"A=1000.0 #Voltage Gain\n",
"B=0.01 #Negative Feedback\n",
"\n",
"#Calculation\n",
"Zid=(1+A*B)*Zi\n",
"# Result\n",
"print \" The Value of the Input Impedance of the Feedback Amplifier is, Zid = \",Zid/10**3,\"K ohm\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" The Value of the Input Impedance of the Feedback Amplifier is, Zid = 11.0 K ohm\n"
]
}
],
"prompt_number": 4
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 12.5 Page no. 401"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"A=1000.0 #60dB, Voltage Gain\n",
"Zo=12000.0 #Ohms\n",
"Zod=600.0 #Ohms\n",
"dAbyA=0.1 #dA/A = 10 %\n",
"\n",
"#Calculation\n",
"B=((Zo/Zod)-1)/A #Zod=Zo/(1+A*B)\n",
"dAfbyAf=1/(1+A*B)*dAbyA #dAf/Af=1/(1+A*B)*dA/A\n",
"# Result\n",
"print \" The Feedback Factor of the Feedback Amplifier is, B = \",B*100,\"percent\"\n",
"print \" The change in overall Gain of the Feedback Amplifier is, dAf/Af = \",dAfbyAf*100,\"percent\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" The Feedback Factor of the Feedback Amplifier is, B = 1.9 percent\n",
" The change in overall Gain of the Feedback Amplifier is, dAf/Af = 0.5 percent\n"
]
}
],
"prompt_number": 6
}
],
"metadata": {}
}
]
}
|
