{
"metadata": {
"name": "J.B.Gupta Chapter 6"
},
"nbformat": 3,
"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": "Chapter 6 Extension of Instrument Range"
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": "Example 6.1,Page No 165"
},
{
"cell_type": "code",
"collapsed": false,
"input": "import math\n \n#variable declaration\nIm = 50*10**-6; #full scale deflection current in A\nRm = 1000; #instrument resistance in \u03a9\nI = 1; #total current to be measured in A\n \n#calculations\nRs = (Rm/float((I/float(Im))-1)); #resistance of ammeter in \u03a9\n \n \n#result\nprint'resistance of ammeter shunt required Rs = %3.7f'%Rs,'\u03a9';\n \n ",
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": "resistance of ammeter shunt required Rs = 0.0500025 \u03a9\n"
}
],
"prompt_number": 3
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": "Example 6.2,Page No 165"
},
{
"cell_type": "code",
"collapsed": false,
"input": "import math\n \n#variable declaration\nRm = 1; #instrument resistance in \u03a9\nRse = 4999; #series resistance in \u03a9\nV = 250; #full-scale deflection voltage in V\nRs = 0.002004; #Shunt resistance in \u03a9(Rs =1/float(499))\nI1 = 50; #full-scale defelction current in A\n \n#calculations\nIm = V/float(Rm+Rse); #full-scale deflection current in A\nx = 1/float(Rse);\nI = Im*(1+(Rm/float(x))); #current in A\nN = I1/float(Im); \nRsh = Rm/float(N-1); #shunt resistance in \u03a9\n \n#result\nprint'full-scale defelction current in Im = %3.2f'%Im,'A';\nprint'current range of instrument when used as an ammeter with coil connected across shunt is I = %3.2f'%I,'A';\nprint'Shunt resistance for the instrument to give a full-scale deflection of 50A is Rsh = %3.2e'%Rsh,'\u03a9';\n \n ",
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": "full-scale defelction current in Im = 0.05 A\ncurrent range of instrument when used as an ammeter with coil connected across shunt is I = 250.00 A\nShunt resistance for the instrument to give a full-scale deflection of 50A is Rsh = 1.00e-03 \u03a9\n"
}
],
"prompt_number": 13
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": "Example 6.3,Page No 167"
},
{
"cell_type": "code",
"collapsed": false,
"input": "import math\n \n#variable declaration\nRm = 10; #instrument resistance in \u03a9\nIm = 0.05; #instrument current in A\nV = 750; #voltage to be measured in V\nI = 100; #current to be measured in A\n \n#calculations\nR = (V/float(Im))-Rm; #External resistance in \u03a9\nN = I/float(Im); #power of shunt\nRs = Rm/float(N-1); #resistance in \u03a9\n \n \n#result\nprint'external resistance to be connected in sereis to enable the instrument to measure voltage upto 750V is %3.1f'%R,'\u03a9';\nprint'shunt resistance required %3.4f'%Rs,'\u03a9';",
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": "external resistance to be connected in sereis to enable the instrument to measure voltage upto 750V is 14990.0 \u03a9\nshunt resistance required 0.0050 \u03a9\n"
}
],
"prompt_number": 18
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": "Example 6.4,Page No 167"
},
{
"cell_type": "code",
"collapsed": false,
"input": "import math\n \n#variable declaration\nRm = 5; #instrument resistance in \u03a9\nIm = 15*10**-3; #full scale defelection current in A\nI =1; #current to be measured in A\nV = 10; #voltage to be measured in V\n \n#calculations\nN = I/float(Im); #power of shunt\nRs = Rm/float(N-1); #resistance in \u03a9\nR = (V/float(Im))-Rm; #series resistance in \u03a9\n \n \n#result\nprint'resistance to be connected in parallel to enable the instrument to measure current upto 1A is %3.4f'%Rs,'\u03a9';\nprint'shunt resistance required for full-scale defelction with 10v is %3.4f'%R,'\u03a9';\n ",
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": "resistance to be connected in parallel to enable the instrument to measure current upto 1A is 0.0761 \u03a9\nshunt resistance required for full-scale defelction with 10v is 661.6667 \u03a9\n"
}
],
"prompt_number": 21
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": "Example 6.5,Page No 167"
},
{
"cell_type": "code",
"collapsed": false,
"input": "import math\n \n#variable declaration\nRm = 2; #instrument coil resistance in \u03a9\nV = 250; #full-scale reading in V\nRs = 5000; #series resistance in \u03a9\nRsh = 2*10**-3; #shunt resistance in \u03a9\n \n \n#calculations\nIm = V/float(Rm+Rs); #current flowing through the instrument for full-scale deflection in A\nIs = (Im*Rm)/float(Rsh); #current through shunt resistance in A \nI = Im+Is; #current range of instrument in A\n \n#result\nprint'current flowing through the instrument for full-scale deflection is %3.4f'%(Im*10**3),'mA';\nprint'current through shunt resistance is %3.2f'%Is,'A';\nprint'current range of instrumentis %3.1f'%I,'A'\n ",
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": "current flowing through the instrument for full-scale deflection is 49.9800 mA\ncurrent through shunt resistance is 49.98 A\ncurrent range of instrumentis 50.0 A\n"
}
],
"prompt_number": 29
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": "Example 6.6,Page No 168"
},
{
"cell_type": "code",
"collapsed": false,
"input": "import math\n \n#variable declaration\nRsh = 0.02; #shunt resistance in \u03a9\nV = 0.5; #potential difference across the shunt in V\nRm = 1000; #resistance in \u03a9\nI1 = 10; #current in A\nI2 = 75; #current in A\nI = 100;\t\t\t #current in A\nx = 40;\t\t\t #deflection %\n \n#calculations\nIs = V/float(Rsh); #current through shunt in A\nIm = V/float(Rm); #current through ammeter for full-scale defelction in A\nV1 = I1*Rsh; #voltage across shunt for 10A in V\nR1 = V1/float(Im);\t\t\t #resistance for the ammeter for a current of 10 A for full-scale defelction in \u03a9\nV2 = I2*Rsh; #voltage across shunt for 75A in V\nR2 = V2/float(Im);\t\t\t #resistance for the ammeter for a current of 75 A for full-scale defelction in \u03a9\nI3 = I*(100/float(x));\t\t\t #full-scale defelction current when 100 A gives 40% defelction\nV3 = I3*Rsh; #voltage across shunt for 250 A in V\nR3 = V3/float(Im);\t\t\t #resistance for the ammeter for a current of 250 A for full-scale defelction in \u03a9\n\n\n#result\nprint'current through ammeter for full-scale defelction is %3.1f'% (Im*10**3),' A'\nprint'Resistance for the ammeter for a current of 10 A for full-scale defelction is %3.2f'%R1,' \u03a9';\nprint'Resistance for the ammeter for a current of 75 A for full-scale defelction is %3.2f'%R2,' \u03a9';\nprint'Resistance for the ammeter for a current of 250 A for full-scale defelction is %3.2f'%R3,' \u03a9';\n",
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": "current through ammeter for full-scale defelction is 0.5 A\nResistance for the ammeter for a current of 10 A for full-scale defelction is 400.00 \u03a9\nResistance for the ammeter for a current of 75 A for full-scale defelction is 3000.00 \u03a9\nResistance for the ammeter for a current of 250 A for full-scale defelction is 10000.00 \u03a9\n"
}
],
"prompt_number": 39
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": "Example 6.7,Page No 168"
},
{
"cell_type": "code",
"collapsed": false,
"input": "import math\n\n#variable declaration\nB = 0.5;\t\t\t #flux density of the magnetic field in Wb/m**2\nN = 100;\t\t\t #number of turns in coil\nl = 0.04;\t\t #length in m\nr =0.03;\t\t\t #width in m\nTc = 120*10**-6;\t #controlling torque in N-m\nv = 1; \t\t\t #volts per division in V\nn = 100;\t\t\t #number of division on full-scale\nRm = 0;\n\n#calculations\nI = Tc/float(B*N*l*r);\t\t #current for full-scale deflection in A\nV = n*v;\t\t\t #full-scale reading of instrument in V\nR = (V/float(I))-Rm;\t\t\t #External resistance required to be put in series with the coil in \u03a9\n\n#result\nprint'current for full-scale deflection is %3.4f'%I,'A';\nprint'External resistance required to be put in series with the coil is %3.3f'%R,' \u03a9';\n\n",
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": "current for full-scale deflection is 0.0020 A\nExternal resistance required to be put in series with the coil is 50000.000 \u03a9\n"
}
],
"prompt_number": 48
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": "Example 6.8,Page No 169"
},
{
"cell_type": "code",
"collapsed": false,
"input": "import math\n\n\n#variable decalaration\nRm = 5;\t\t #coil resistance in \u03a9\nRm1 = 0.00075;\t\t #coil resistance in \u03a9\nIm = 0.015;\t\t #full-scale defelction current in A\nI = 100; \t\t #current to be measured in A\nT1 = 0.004;\t\t #temperature coeficient of copper in \u03a9/\u03a9/\u00b0C\nT2 = 0.00015;\t\t #temperature coeficient of manganin in \u03a9/\u03a9/\u00b0C\nT =10; \t\t #rise in temperature in \u00b0C\n#calculations\nN = I/float(Im);\t\t #multiplying power of shunt\nRs = Rm/float(N-1);\t #resistance of manganin shunt in \u03a9\nRc = Rm*(1+(T1*T));\t #coil resitance with 10\u00b0C in temperature in \u03a9\nRsh = Rm1*(1+(T2*T));\t #shunt resitance with 10\u00b0C in temperature in \u03a9\nIn = (Rsh/float(Rc+Rsh))*100;\t#new instrument current in A\nr = (In/float(Im))*100;\t\t#new instrument reading in A\ne = ((r-I)/float(I))*100;\t\t#percentage error in %\n\n\n#result\nprint'percentage error %3.5f'%e,'%';",
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": "percentage error -3.71583 %\n"
}
],
"prompt_number": 83
},
{
"cell_type": "code",
"collapsed": false,
"input": "",
"language": "python",
"metadata": {},
"outputs": []
}
],
"metadata": {}
}
]
}