{ "metadata": { "name": "" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 10 : Bridge Circuits" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example10_1,pg 292" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# wheatstone bridge\n", "\n", "import math\n", "#Variable declaration\n", "Vs=12.0 #source voltage\n", "R=120.0 #resistance of arms \n", "delv=0.3 #variation in output voltage(+/-)0.3\n", "Rm=100.0 #meter resistance\n", "\n", "\n", "#Calculations\n", "delRbyR=(4.0/Vs)*(delv)*100\n", "delIm=(delRbyR/100.0)/(4.0*R*(1+(Rm/R)))\n", "\n", "#Result\n", "print(\"percent change in resistance:\")\n", "print(\"delRbyR = %.f%% \\n\"%delRbyR)\n", "print(\"current variation:\")\n", "print(\"delIm = %.6f A\"%delIm)\n", "# Answer current variation is not matchhing with the book" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "percent change in resistance:\n", "delRbyR = 10% \n", "\n", "current variation:\n", "delIm = 0.000114 A\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example10_2,pg 295" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# high resistance measurement bridge\n", "\n", "import math\n", "#variable declaration\n", "#in absence of the guard point arrangement, two 10^10 ohm resistances in series become parallel \n", "#to the 10^9 ohm resistance, making the effective unknown resistance\n", "\n", "#case-1\n", "Rh=10.0**9\n", "Ra1=10.0**10\n", "Rb1=10.0**10\n", "#case-2 \n", "Ra2=10.0**9\n", "Rb2=10.0**9\n", "\n", "#Calculations\n", "Rue1=((Rh*2*Ra1)/(Rh+(2*Ra1))) #effective resistance\n", "err1=((Rh-Rue1)/Rh)*100 #percentage error\n", "Rue2=((Rh*2*Ra2)/(Rh+(2*Ra2))) #effective resistance\n", "err2=((Rh-Rue2)/Rh)*100 #percentage error\n", "\n", "#Result\n", "print(\"percentage error case-1:\")\n", "print(\"err1 = %.0f%% \\n\"%err1)\n", "print(\"percentage error case-2:\")\n", "print(\"err2 = %.1f%%\"%err2)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "percentage error case-1:\n", "err1 = 5% \n", "\n", "percentage error case-2:\n", "err2 = 33.3%\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example10_3,pg 297" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# capacitance and resistance of AC bridge\n", "import math\n", "#Variable declaration\n", "Z1=20.0+80.0j #impedance in first arm\n", "Z2=200.0 #impedance in second arm\n", "Z3=100.0+200.0j #impedance in third arm\n", "f=50.0 #excitation frequency\n", "\n", "#Calculations\n", "Zu=((Z2*Z3)/Z1) #impedance of fourth arm\n", "Cu=(1.0/(2*math.pi*f*Zu.real)) #capacitance in fourth arm\n", "Ru=-Zu.imag #resistance in fourth arm\n", "\n", "#Result\n", "print(\"capacitance in fourth arm:\")\n", "print(\"Cu = %f F\\n\"%(Cu*10**6))\n", "print(\"resistance in fourth arm:\")\n", "print(\"Ru = %.2f ohm\"%Ru)\n", "#Answer is slightly different than book" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "capacitance in fourth arm:\n", "Cu = 6.012520 F\n", "\n", "resistance in fourth arm:\n", "Ru = 117.65 ohm\n" ] } ], "prompt_number": 15 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example10_4,pg 301" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# schering bridge\n", "\n", "import math\n", "#Variable declaration\n", "C3=0.001*10**-6 #capacitor\n", "Fd=6.0*10**-4 #dissipation factor\n", "f=1.0*10**3 #schering bridge frequency\n", "R1=10.0*10**3\n", "R2=10.0*10**3\n", "\n", "\n", "#Calculations\n", "Ru=(Fd/(2*math.pi*f*C3)) #standard resistor\n", "C1=C3*(1/R2)*Ru\n", "\n", "#Result\n", "print(\"standard resistor:\")\n", "print(\"Ru = %.3f ohm\\n\"%Ru)\n", "print(\"capacitor:\")\n", "print(\"C1 = %.1f pF\"%(C1*10**12))\n", "#Answer do not match with the book" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "standard resistor:\n", "Ru = 95.493 ohm\n", "\n", "capacitor:\n", "C1 = 9.5 pF\n" ] } ], "prompt_number": 25 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example10_5,pg 303" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# wein bridge\n", "\n", "import math\n", "#Variable declaration\n", "R=10*10**3 #resistor\n", "C=0.001*10**-6 #capacitor\n", "R3=10.0*10**3 #reistance in third arm\n", "\n", "#Calculations\n", "f=(1.0/(2*math.pi*R*C)) #supply frequency\n", "R4=(R3/2) #reistance in fourth arm\n", "\n", "#Result\n", "print(\"supply frequency:\")\n", "print(\"f = %.2f kHz\\n\"%(f/1000))\n", "print(\"reistance in fourth arm:\")\n", "print(\"R4 = %.1f k-ohm\"%(R4/1000))" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "supply frequency:\n", "f = 15.92 kHz\n", "\n", "reistance in fourth arm:\n", "R4 = 5.0 k-ohm\n" ] } ], "prompt_number": 27 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example10_6,pg 303" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# balance condition in wein bridge\n", "\n", "import math\n", "#Variable declaration\n", "f=47.76*10**3 #supplu frequency\n", "C=10**-9 #assume\n", "\n", "#Calculations\n", "CR=(1.0/(2*math.pi*f)) #resistor capacitor product\n", "R=(CR/C) #resistor\n", "\n", "#Result\n", "print(\"for (R3/R4) = 2\\nR3 and R4 may be maintained at earlier values\")" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "for (R3/R4) = 2\n", "R3 and R4 may be maintained at earlier values\n" ] } ], "prompt_number": 8 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example10_7,pg 309" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# relation between Vo and t for Vi given\n", "\n", "import math\n", "#Variable declaration\n", "a1=3.81*10**-3\n", "a2=-6.17*10**-7\n", "#R1=(R2/2),i.e R2/R1=2\n", "R1=10*10**3\n", "R2=20*10**3\n", "R5=4*10**3\n", "R6=20*10**3\n", "\n", "#Calculations\n", "B=(R5/(R5+R6))\n", "#using relation 10.68(b)\n", "\n", "#Result\n", "print(\"(Vo/Vi)= (-3.05*10^-3)t/(1+0.76*10^-3)t\")\n", "print(\"thus for, t<=130 C, Vo is approx. linear. This however can be extended with proper choice\")\n", "print(\"i.e R5 and R6 in relation to R1,R3 and R4\")" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(Vo/Vi)= (-3.05*10^-3)t/(1+0.76*10^-3)t\n", "thus for, t<=130 C, Vo is approx. linear. This however can be extended with proper choice\n", "i.e R5 and R6 in relation to R1,R3 and R4\n" ] } ], "prompt_number": 11 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example10_8,pg 503" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# find deflection in galvanometer\n", "\n", "import math\n", "#Variable declaration\n", "R1=120.0 #resistance of arm-1\n", "R2=120.0 #resistance of arm-2\n", "R3=120.0 #resistance of arm-3\n", "R4=121.0 #resistance of arm-4\n", "Rm=100.0 #meter resistance\n", "Vs=6.0 #source voltage\n", "n=1*10**-3 #meter sensitivity\n", "\n", "\n", "#Calculations\n", "k=(R3/(R3+R4))\n", "k = math.floor(k*10**3)/10**3\n", "Vm=Vs*((R1/(R1+R2))-k) #voltage across meter\n", "Rb=((R1*R2)/(R1+R2))+((R3*R4)/(R3+R4)) #thevenised bridge resistance\n", "Rb=math.floor(Rb*1000)/1000 \n", "Ig=(Vm/(Rb+Rm)) #current through galvanometer\n", " \n", "D=Ig*10**6\n", "\n", "#Result\n", "print(\"deflection in meter:\")\n", "print(\"D = %f mm\"%D)\n", "#Calcualtions in the book are not correct" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "deflection in meter:\n", "D = 81.726054 mm\n" ] } ], "prompt_number": 49 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example10_9,pg 503" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# find insulating post resistance\n", "\n", "import math\n", "#Variable declaration\n", "err=0.5/100.0 #(+/-)0.5%\n", "R=100.0*10**6 #test resistance\n", "\n", "#Calculations\n", "#Re=((R*2*Rip)/(R+(2*Rip)))\n", "Re1=R-(err*R) #err=+0.5\n", "Re2=R+(err*R) #err=-0.5\n", "Rip1=((R*Re1)/(2*(R-Re1))) #err=+0.5\n", "Rip2=((R*Re2)/(2*(Re2-R))) #err=-0.5\n", "\n", "\n", "#Result\n", "print(\"resistance of each insulating post-1:\")\n", "print(\"Rip1 = %.2f M-ohm\\n\"%(Rip1*10**-6))\n", "print(\"resistance of each insulating post-2:\")\n", "print(\"Rip2 = %.2f M-ohm\"%(Rip2*10**-6))\n", "# Answer in the book are not matching" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "resistance of each insulating post-1:\n", "Rip1 = 9950.00 M-ohm\n", "\n", "resistance of each insulating post-2:\n", "Rip2 = 10050.00 M-ohm\n" ] } ], "prompt_number": 61 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example10_10,pg 504\n" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# maxwell bridge\n", "\n", "import math\n", "#Variable declaration\n", "Ru=130.0 #resistance\n", "Lu=31*10**-3 #inductance \n", "R2=10*10**3 #resistance in arm-2\n", "C1=0.01*10**-6 #capacitance in arm\n", "\n", "#Calculations\n", "R3=(Lu/(C1*R2)) #resistance in arm-3\n", "R1=((R2*R3)/Ru) #resistance in arm-1\n", "\n", "#Result\n", "print(\"R1 = %.2f k-ohm\"%(R1/1000))\n", "print(\"R3 = %.f ohm\"%R3)\n", "print(\"yes values are unique\")" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "R1 = 23.85 k-ohm\n", "R3 = 310 ohm\n", "yes values are unique\n" ] } ], "prompt_number": 64 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example10_11,pg 504" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# hay bridge\n", "\n", "import math\n", "#Variable declaration\n", "f=1000.0 #supply frequency\n", "C1=0.04*10**-6 #capacitance\n", "R1=220.0 #resistance in arm-1\n", "R2 = 10*10**3 #resistance in arm-2\n", "Lu=22.0*10**-3 #inductance\n", "\n", "\n", "#Calculations\n", "pi= math.floor(math.pi*100)/100\n", "Ru=((2*pi*f)**2)*C1*R1*Lu #resistance\n", "R3=((R1*Ru)+(Lu/C1))/R2 #resistance in arm-3\n", "\n", "#Result\n", "print(\"resistance of inductor:\")\n", "print(\"Ru = %.3f ohm\\n\"%Ru)\n", "print(\"resistance of arm-3:\")\n", "print(\"R3 = %.2f ohm\"%R3)\n", "#Answer for R3 is not matching." ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "resistance of inductor:\n", "Ru = 7.635 ohm\n", "\n", "resistance of arm-3:\n", "R3 = 55.17 ohm\n" ] } ], "prompt_number": 74 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example10_12,pg 505" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# find C1 C3 and dissipation factor\n", "\n", "import math\n", "#Variable declaration\n", "C4=0.0033*10**-6 #lossy capacitor\n", "R2=12.0*10**3 #arm-2 resistance\n", "R1=10.0*10**3 #arm-1 resistance\n", "f = 50.0 # frequency\n", "\n", "#Calculations\n", "C3=((C4*R2)/R1) #standard capacitance\n", "R4=0.1\n", "C1=((R4*C3)/R2)\n", "Fd=2*math.pi*f*C4*R4 #dissipation factor\n", "\n", "#Result\n", "print(\"capacitance set value:\")\n", "print(\"C1 = %.5f * 10^12 F\\n\"%(C1*10**12))\n", "print(\"value of standard capacitance:\")\n", "print(\"C3 = %.5f *10^6 F\\n\"%(C3*10**6))\n", "print(\"dissipation factor:\")\n", "print(\"Fd = %.4f * 10^-6\"%(math.floor(Fd*10**10)/10**4))\n", "#Answer for C1 is wrong" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "capacitance set value:\n", "C1 = 0.03300 * 10^12 F\n", "\n", "value of standard capacitance:\n", "C3 = 0.00396 *10^6 F\n", "\n", "dissipation factor:\n", "Fd = 0.1036 * 10^-6\n" ] } ], "prompt_number": 7 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example10_13,pg 505" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# wein bridge\n", "\n", "import math\n", "#Variable declaration\n", "f=10.0*10**3 #supply frequency\n", "R1=10.0*10**3 #reistance of arm-1\n", "C1=0.01*10**-6\n", "C2=0.01*10**-6\n", "R3=20*10**3 #resistance of arm-3\n", "\n", "#Calaculations\n", "R2=(1/(f**2))*(1/(C1*C2*R1)) #resistance of arm-2\n", "R4=(R3/((R1/R2)+(C2/C1))) #resistance of arm-4\n", "\n", "#Result\n", "print(\"resistance of arm-2:\")\n", "print(\"R4 = %.f k-ohm\\n\"%(R2/1000))\n", "print(\"resistance of arm-4:\")\n", "print(\"R2 = %.f k-ohm\\n\"%(R4/1000))" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "resistance of arm-2:\n", "R4 = 10 k-ohm\n", "\n", "resistance of arm-4:\n", "R2 = 10 k-ohm\n", "\n" ] } ], "prompt_number": 12 } ], "metadata": {} } ] }