{
 "metadata": {
  "name": "",
  "signature": "sha256:8e01926cf42f8b82c73cff46263ef90c672622041c85ff2d1b1ef7a3962ce2cc"
 },
 "nbformat": 3,
 "nbformat_minor": 0,
 "worksheets": [
  {
   "cells": [
    {
     "cell_type": "heading",
     "level": 1,
     "metadata": {},
     "source": [
      "Chapter 8: D.C. Transients"
     ]
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 8.1, 253"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#Variable declaration\n",
      "C = 8e-06;    # Value of capacitance of capacitor, farad\n",
      "R = 0.5e+06;    # Value of series resistor, ohm\n",
      "E = 200;    # Value of d.c. voltage supply, volt\n",
      "\n",
      "#Calculations&Results\n",
      "# Part (a)\n",
      "tau = C*R;    # Time constant of the R-C circuit while charging, s\n",
      "print \"The circuit time constant while charging = %1d s\"%tau\n",
      "\n",
      "# Part (b)\n",
      "I_0 = E/R;    # Initial charging current through capacitor, A\n",
      "print \"The initial charging current through capacitor = %3d micro-ampere\"%(I_0/1e-06);\n",
      "\n",
      "# Part (c)\n",
      "t = 4;  # Time after the supply is connected, s\n",
      "v_C = 0.632*E;  # p.d. across the capacitor 4s after the supply is connected, V\n",
      "v_R = E - v_C;  # p.d. across the resistor 4s after the supply is connected, V\n",
      "print \"The p.d. across resistor and capacitor %d s after the supply is connected = %5.1f V and %4.1f V respectively\"%(t, v_C, v_R);\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "The circuit time constant while charging = 4 s\n",
        "The initial charging current through capacitor = 400 micro-ampere\n",
        "The p.d. across resistor and capacitor 4 s after the supply is connected = 126.4 V and 73.6 V respectively\n"
       ]
      }
     ],
     "prompt_number": 1
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 8.2, Page 255"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#Variable declaration\n",
      "C = 0.5e-06;    # Value of capacitance of capacitor, farad\n",
      "R1 = 220e+03;    # Value of series resistor, ohm\n",
      "R2 = 110e+03;    # Value of parallel resistor, ohm\n",
      "E = 150;    # Value of d.c. voltage supply, volt\n",
      "\n",
      "#Calculations&Results\n",
      "# Part (a)\n",
      "tau = C*R1;    # Time constant of the R1-C circuit while charging, s\n",
      "print \"The circuit time constant while charging = %4.2f s\"%tau\n",
      "I_0 = E/R1;    # Initial charging current through capacitor, A\n",
      "print \"The initial charging current through capacitor = %3d micro-ampere\"%(I_0/1e-06)\n",
      "\n",
      "# Part (b)\n",
      "tau = C*(R1+R2);    # Time constant of the R1-C-R2 circuit while discharging, s\n",
      "print \"The circuit time constant while discharging = %4.2f s\"%tau\n",
      "I_0 = E/(R1 + R2);    # Initial discharging current through capacitor, ampere\n",
      "i = 0.368*I_0;    # Discharge current after one time constant, ampere\n",
      "V_R2 = i*R2;    # Potential difference across R2 after one time constant, volt\n",
      "print \"The p.d. across R2 after one time constant while discharging = %4.1f volt\"%V_R2\n",
      "\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "The circuit time constant while charging = 0.11 s\n",
        "The initial charging current through capacitor = 681 micro-ampere\n",
        "The circuit time constant while discharging = 0.16 s\n",
        "The p.d. across R2 after one time constant while discharging = 18.4 volt\n"
       ]
      }
     ],
     "prompt_number": 2
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 8.3, Page 258"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#Variable declaration\n",
      "E = 110.;    # Value of d.c. voltage supply, volt\n",
      "L = 1.5;    # Inductor value, henry\n",
      "R = 220;    # Value of series resistor, ohm\n",
      "\n",
      "#Calculations&Results\n",
      "# Part (a)\n",
      "di_dt = E/L;    # The initial rate of change of current through inductor, H\n",
      "print \"The initial rate of change of current through inductor = %5.2f A/s\"%di_dt\n",
      "\n",
      "# Part (b)\n",
      "I = E/R;    # The final steady current, A\n",
      "print \"The final steady current through inductor = %3.1f A\"%I\n",
      "\n",
      "# Part (c)\n",
      "tau = L/R;    # The time taken for the current to reach its fi nal steady value, s\n",
      "print \"The time taken for the current to reach its final steady value = %4.1f ms\"%(5*tau/1e-03);\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "The initial rate of change of current through inductor = 73.33 A/s\n",
        "The final steady current through inductor = 0.5 A\n",
        "The time taken for the current to reach its final steady value = 34.1 ms\n"
       ]
      }
     ],
     "prompt_number": 3
    }
   ],
   "metadata": {}
  }
 ]
}