{ "metadata": { "name": "ch_8" }, "nbformat": 2, "worksheets": [ { "cells": [ { "cell_type": "markdown", "source": [ "

Chapter 8: Voltage Regulators

" ] }, { "cell_type": "markdown", "source": [ "

Example No. 8.1 Page No:362

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "'''Linear Voltage Regulator'''", "", "#Variable Declaration:", "Vo=15.0 #Output voltage in volt", "Vr=2.0 #Ripple voltage in volt", "", "#Calculations:", "Vimin=Vo+3.0 #Calculating minimum input voltage ", "", "Vi=Vimin + Vr/2.0 #Calculating input voltage", "", "Vz=Vi/2.0 #Calculating zener voltage", "", "Vz=10.0 #Volatge in volt", "Iz=20.0*10**-3 #Current in ampere", "", "R1=(Vi-Vz)/Iz #Calculating resistance value", " ", "I2=50.0*10**-6 #Current ampere", "R2=(Vo-Vz)/I2 #Calculating Resistance value", "R2=R2/1000.0 #Calculating resistance value", "", "R3=Vz/I2 #Calculating resistance value", "R3=R3/1000.0 #Calculating resistance value", "", "Vcemax=Vi+Vr/2 #Calculating volatge", "", "IE=50.0*10**-6 #Current in ampere", "IL=50.0*10**-6 #Current in ampere", "", "P=(Vi-Vo)*IL #Calculating power ", "P1=P*1000000.0 #Calculating power", "", "", "#Results:", "print('As Vz=%.1f, use Zener diode 1N758 for 10V'%Vz)", "print('\\nR1= %d ohm'%R1)", "print('\\nR2= %.1f kohm'%R2)", "print('\\nR3= %d kohm'%R3)", "print('\\nSelect C1= 50uF')", "print('\\nP= %.1f mW'%P1)", "print('\\nUse the transstor 2N718 for Q1')" ], "language": "python", "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "As Vz=10.0, use Zener diode 1N758 for 10V", "", "R1= 450 ohm", "", "R2= 100.0 kohm", "", "R3= 200 kohm", "", "Select C1= 50uF", "", "P= 200.0 mW", "", "Use the transstor 2N718 for Q1" ] } ], "prompt_number": 1 }, { "cell_type": "markdown", "source": [ "

Example No. 8.2, Page No: 366

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "'''7805 Voltage Regulator'''", "", "#Variable Declaration:", "IL=0.25 #Current in ampere", "Vr=5.0 #Ripple voltage in volt", "", "#Calculations:", "R=Vr/IL #Calculating value of resistance ", "RL=10.0 #Calculating value of resistance", "VL=IL*RL #Calculating voltage", "", "Vo=Vr+VL #Calculating output voltage", "Vdrop=2.0 #Voltage drop in volt", "Vi=Vo+Vdrop #Calculating voltage", "", "#Results:", "print('R= %d ohm'%R)", "print('\\nVo= %.1f V'%Vo)", "print('\\nVo= %.1f V'%Vi)" ], "language": "python", "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "R= 20 ohm", "", "Vo= 7.5 V", "", "Vo= 9.5 V" ] } ], "prompt_number": 2 }, { "cell_type": "markdown", "source": [ "

Example No. 8.3, Page No: 368

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "'''7805 Regulator Circuit'''", "", "#Variable Declaration:", "VL=5.0 #Voltage in volt", "RL=100.0 #Resistance in ohm", "", "#Calculations:", "IL=VL/RL #Calculating current ", "IL1=IL*1000.0 #Calculating current", "#Part A", "R1=7.0 #Resistance in ohm ", "VR1=IL*R1 #Calculaing voltage drop across R1", "VR1x=VR1*1000.0 #Calculatingvoltage drop across R1", "", "#Part B", "VLb=5.0 #Voltage in volt", "RLb=2.0 #Resistance in ohm", "", "ILb=VLb/RLb #Calculating current", "", "R1=7.0 #Resistance in ohm ", "VR1=ILb*R1 #Calculating voltage drop accross R1", "", "Io=0.147 #Current in ampere ", "Ic=ILb-Io #Calculating current", "", "#Results:", "print('Part A')", "print('\\nLoad Current IL= %d mA'% IL1)", "print('\\nVoltage accross R1= %d mV'%VR1x)", "print('\\nAs voltage < 0.7V, Q1 is OFF')", "print('\\nHence IL=Io=Ii=50 mA')", "print('\\n\\nPart B')", "print('\\nLoad Current IL= %.1f A'%ILb)", "print('\\nVoltage accross R1= %.1f V'%VR1)", "print('\\nAs voltage > 0.7V, Q1 is ON')", "print('\\nHence Ic= %.3f A'%Ic)" ], "language": "python", "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Part A", "", "Load Current IL= 50 mA", "", "Voltage accross R1= 350 mV", "", "As voltage < 0.7V, Q1 is OFF", "", "Hence IL=Io=Ii=50 mA", "", "", "Part B", "", "Load Current IL= 2.5 A", "", "Voltage accross R1= 17.5 V", "", "As voltage > 0.7V, Q1 is ON", "", "Hence Ic= 2.353 A" ] } ], "prompt_number": 1 }, { "cell_type": "markdown", "source": [ "

Example No. 8.4, Page No: 371

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "'''LM317 Regulator'''", "", "#Variable Declaration:", "R1=240.0 #Resistance in ohm", "R2=2000.0 #Resistance in ohm", "Iadj=50.0*10**-6 #Current in ampere", "Vref=1.25 #Reference voltage in volt ", "", "#Calculation:", "Vo=(Vref*(1+R2/R1))+(Iadj*R2) #Calculating output voltage", "", "#Result:", "print('Vo= %.2f V'%Vo)" ], "language": "python", "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Vo= 11.77 V" ] } ], "prompt_number": 4 }, { "cell_type": "markdown", "source": [ "

Example No. 8.5, Page NO:371

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "'''Voltage regulator using LM317'''", "", "#Variable Declaration:", "Iadjmax=100.0*10**-6 #Current in ampere", "R1=240.0 #Resistance in ohm", "Vref=1.25 #Reference voltage in volt ", " ", "#Calculations:", "#First case: Vo=4", "Vo=4.0 #Voltage in volt", "R2a1=(Vo-Vref)/(Vref/R1 + Iadjmax) #Calculating value of resistance", "R2a=R2a1/1000.0 #Calculating value of resistance", "", "#First case: Vo=12", "Vo=12.0 #Voltage in volt", "R2b1=(Vo-Vref)/(Vref/R1 + Iadjmax) #Calculating value of resistance", "R2b=R2b1/1000.0 #Calculating value of resistance", "", "#Results:", "print('\\nR2= %.2f kohm'%R2a)", "print('\\nR2= %.2f kohm'%R2b)" ], "language": "python", "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "", "R2= 0.52 kohm", "", "R2= 2.03 kohm" ] } ], "prompt_number": 5 }, { "cell_type": "markdown", "source": [ "

Example No.8.6, Page No: 377

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "'''Current Limiting Circuit'''", "", "#Variable Declaration:", "ILmax=0.5 #Current in ampere", "", "#Calculations:", "#Part 1", "Rsc=0.7/ILmax #Calculting value of resistance", "", "#Part 2", "RL=100.0 #Resistance in ohm", "Vo=20.0 #Voltage in volt", "", "IL1=Vo/RL #Calculating current", "", "#Part 3", "RLn=10.0 #Resistance in ohm", "", "IL2=Vo/RLn #Calculating current", "Von=RLn*ILmax #Calculating voltage", "", "#Results:", "print('Rsc= %.1f ohm'%Rsc)", "print('\\nIL= %.1f A'%IL1)", "print('\\nIL= %.1f A'%IL2)", "print('\\nSince IL > ILmax of 0.5A, current limiting will happen')", "print('\\nVo= %.1f V'%Von)" ], "language": "python", "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Rsc= 1.4 ohm", "", "IL= 0.2 A", "", "IL= 2.0 A", "", "Since IL > ILmax of 0.5A, current limiting will happen", "", "Vo= 5.0 V" ] } ], "prompt_number": 2 }, { "cell_type": "markdown", "source": [ "

Example No. 8.7, Page No: 378

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "''' LM723 Regulator'''", "", "#Variable Declaration:", "R2=10000.0 #Resistance in ohm ", "Vo=12.0 #Output voltage in volt", "Vref=7.15 #Reference voltage", "", "#Calculations:", "R1=(Vo/Vref)*R2 - R2 #Calculating resistance value", "R1a=R1/1000.0 #Calculating resistance value", "", "#Result:", "print('\\nR1= %.2f kohm'%R1a)" ], "language": "python", "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "", "R1= 6.78 kohm" ] } ], "prompt_number": 3 }, { "cell_type": "markdown", "source": [ "

Example No.8.8, Page NO: 380

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "'''Continuously adjustable power supply'''", "", "#Variable Declaration:", "Vref=7.15 #Reference voltage in volt", "Vo=5.0 #Output voltage in volt", "", "#Calculations:", "k=Vref/Vo ", "k1=k-1", "", "#For min voltage of 2V", "Vom=2.0 ", "km=Vref/Vom", "km1=km-1.43", "", "R1a=10000.0 #Resistance in ohm", "R1b=2000.0 #Resistance in ohm", " ", "R2=R1a/2.145 #Calculating resistance value", "R2n=R2/1000.0 #Calculating resistance value", "", "R1=6000.0 #Resistance in ohm", "R3=(R1*R2)/(R1+R2) #Calculating resistance value", "R3n=R3/1000.0 #Calculating resistance value", "", "#Results:", "print('(R1b+R2)/R2= %.2f'%k)", "print('\\nR1 = %.2f * R2'%k1)", "print('\\n(R1a+R1b+R2)/R2= %.3f'%km)", "print('\\nR1a = %.3f * R2'%km1)", "print('\\nR2= %.2f kohm'%R2n)", "print('\\nR3= %.2f kohm'%R3n)" ], "language": "python", "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(R1b+R2)/R2= 1.43", "", "R1 = 0.43 * R2", "", "(R1a+R1b+R2)/R2= 3.575", "", "R1a = 2.145 * R2", "", "R2= 4.66 kohm", "", "R3= 2.62 kohm" ] } ], "prompt_number": 4 }, { "cell_type": "code", "collapsed": true, "input": [], "language": "python", "outputs": [] } ] } ] }