{ "metadata": { "name": "" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 5 : Power Amplifiers" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 5.1, Page No. 167" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# efficiency\n", "\n", "import math\n", "#Variable declaration\n", "Pac=0.1 #in W\n", "Vcc=20.0 #in V\n", "Ic=20.0 #in mA\n", "\n", "#Calculations\n", "Pdc=Vcc*Ic*10**-3 #in W\n", "eta=(Pac/Pdc)*100 #efficiency\n", "\n", "#Result\n", "print(\"efficiency is ,(%%)= %.f\"%eta)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "efficiency is ,(%)= 25\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 5.2, Page No. 167" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# collector current\n", "\n", "import math\n", "#Variable declaration\n", "Pac=2.0 #in W\n", "Vcc=12.0 #in V\n", "\n", "#Calculations\n", "Ic=(Pac*math.sqrt(2)*math.sqrt(2))/Vcc\n", "\n", "#Result\n", "print(\"maximum collector current is ,(A)= %.2f\" %Ic)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "maximum collector current is ,(A)= 0.33\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 5.3, Page No. 167" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# collector efficiency and power rating\n", "\n", "import math\n", "#Variable declaration\n", "Pac=3.0 #in W\n", "Pdc=10.0 #in W\n", "\n", "#Calculations\n", "eta=(Pac/Pdc)*100 #percentage efficieny \n", "\n", "#Result\n", "print(\"collector efficiency is , (%%) = %.f\"%eta)\n", "print(\"power rating of transistor is ,(W) = %.f\" %Pdc)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "collector efficiency is , (%) = 30\n", "power rating of transistor is ,(W) = 10\n" ] } ], "prompt_number": 11 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 5.4, Page No. 168" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# power\n", "\n", "import math\n", "#Variable declaration\n", "dIc=100.0 #in mA\n", "Rl=6.0 #in ohm\n", "Rl=6.0 #in ohm\n", "dVc=10.0 #in V\n", "\n", "#Calculations\n", "mv=dIc*Rl*10**-3 #in V\n", "pd=mv*dIc #in mW\n", "oi=(dVc/dIc)*10**3 #in ohm\n", "n=math.sqrt(oi/Rl) #turn ratio of transformer\n", "tsv=dVc/n #om V\n", "Il=tsv/Rl #in A\n", "ptr= Il**2*Rl*10**3 #in mW\n", "\n", "#Result\n", "print(\"(i) power developed in loudspeaker is , (mW)= %.f\"%pd)\n", "print(\"(ii) power transferred to loudspeaker is ,(mw)= %.f\"%ptr)\n", "#in textbook in second case there is one point deviation in the answer." ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(i) power developed in loudspeaker is , (mW)= 60\n", "(ii) power transferred to loudspeaker is ,(mw)= 1000\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 5.5, Page No. 168" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# power\n", "\n", "import math\n", "#Variable declaration\n", "n=10.0 #turn ratio\n", "Rl=10.0 #ohm\n", "Ic=100.0 #in mA\n", "\n", "#Result\n", "Rld=n**2*Rl #in ohm\n", "Irms=Ic/(math.sqrt(2)) #in mA\n", "P=Irms**2*Rld #in W\n", "\n", "#Result\n", "print(\"maximum power output is ,(W)= %.f\"%(P*10**-6))" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "maximum power output is ,(W)= 5\n" ] } ], "prompt_number": 20 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 5.6, Page No. 169" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# harmonic distortions and change in power\n", "\n", "import math\n", "#Variable declaration\n", "#ie=15*sin 400*t+1.5*sin 800*t + 1.2*sin 1200*t + 0.5*sin 1600*t given equation\n", "I2=1.5 #in A\n", "I1=15.0 #in A\n", "I3=1.2 #in A\n", "I4=0.5 #in A\n", "D2=(I2/I1)*100 #Second percentage harmonic distortion\n", "D3=(I3/I1)*100 #Third percentage harmonic distortion\n", "#in book I2 is mentioned wrongly in place of I1\n", "D4=(I4/I1)*100 #Fourth percentage harmonic distortion\n", "D=math.sqrt(D2**2+D3**2+D4**2)/100 #Distortion Factor\n", "P1=1.0 #assume\n", "P=(1+D**2)*P1 #in W\n", "peri=((P-P1)/P1)*100 #percentage increase in power due to distortion\n", "\n", "#Result\n", "print(\"part (i)\")\n", "print(\"Second percentage harmonic distortion (D2) is ,(%%) = %.f\"%D2)\n", "print(\"Third percentage harmonic distortion (D3) is ,(%%) = %.f\"%D3)\n", "print(\"Fourth percentage harmonic distortion (D4) is ,(%%) = %.2f\"%D4)\n", "print(\"\\npart (ii)\")\n", "print(\"percentage increase in power due to distortion is ,(%%) = %.2f\"%peri)\n", "# answer for % increase is slightly different than book" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "part (i)\n", "Second percentage harmonic distortion (D2) is ,(%) = 10\n", "Third percentage harmonic distortion (D3) is ,(%) = 8\n", "Fourth percentage harmonic distortion (D4) is ,(%) = 3.33\n", "\n", "part (ii)\n", "percentage increase in power due to distortion is ,(%) = 1.75\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 5.7, Page No. 169" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# power dissipated\n", "\n", "import math\n", "#Variable declaration\n", "Vcc=15.0 #in V\n", "Vpeak=24.0/2 #in V\n", "Rl=100.0 #in ohm\n", "\n", "#Calculations\n", "Ipeak= Vpeak/Rl #in A\n", "Pdc=Vcc*(2/(math.pi))*Ipeak #in W\n", "pad=(1.0/2)*(Vpeak**2)/Rl #in W\n", "pd=Pdc-pad #in W\n", "pde=pd/2 #in W\n", "\n", "#Result\n", "print(\"power dissipated by each transistor is,(mW)= %.f\"%(pde*10**3))" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "power dissipated by each transistor is,(mW)= 213\n" ] } ], "prompt_number": 28 } ], "metadata": {} } ] }