Merge pull request #1 from prashantsinalkar/masterHEADmaster

Initial commit

10 files changed, 3325 insertions, 0 deletions

diff --git a/Introduction_to_Electric_Drives_by_J_S_Katre/1-Thyristors.ipynb b/Introduction_to_Electric_Drives_by_J_S_Katre/1-Thyristors.ipynb
new file mode 100644
index 0000000..cbb9bb0
--- /dev/null
+++ b/Introduction_to_Electric_Drives_by_J_S_Katre/1-Thyristors.ipynb
@@ -0,0 +1,219 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 1: Thyristors"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.11_1: peak_reverse_recovery_current.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 1.11.1: peak reverse recovery current\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"//given data :\n",
+"itt=10;// time in micro seconds\n",
+"qtt=150;//charge in micro colums\n",
+"prrc=((2*qtt)/itt);//peak reverse recovery current in amperes\n",
+"disp(prrc,'peak reverse recovery current in amperes')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.18_1: voltage.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 1.18.1: voltage of the capacitor\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"format('v',7)\n",
+"r=10;//in ohms\n",
+"l=10;///inductance in mH\n",
+"c=10;//capacitance in micro farads\n",
+"v=100;//in volts\n",
+"t=((%pi)/(sqrt((1/(l*10^-3*c*10^-6))-(r^2/(4*(l*10^-3)^2)))));// time in seconds\n",
+"vc= v*(1-cosd(t/(sqrt(l*10^-3*c*10^-6))));//in volts\n",
+"disp(vc,'the capacitor voltage in volts is')\n",
+"//answer is wrong in the textbook"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.18_2: voltage_of_the_capacitor.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 1.18.2: voltage of the capacitor\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"format('v',7)\n",
+"r=15;//in ohms\n",
+"l=12;///inductance in mH\n",
+"c=8;//capacitance in micro farads\n",
+"v=100;//in volts\n",
+"t=((%pi)/(sqrt((1/(l*10^-3*c*10^-6))-(r^2/(4*(l*10^-3)^2)))));// time in seconds\n",
+"vc= v*(1-cosd(t/(sqrt(l*10^-3*c*10^-6))));//in volts\n",
+"disp(vc,'the capacitor voltage in volts is')\n",
+"//this question is not solved in the textbook"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.20_1: turn_off_time.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 1.20.1: Turn Off Time\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"//given data :\n",
+"format('v',6)\n",
+"Vs=200;//in volts\n",
+"R1=10;// in ohm\n",
+"R2=R1;\n",
+"C=5;// in micro-farad\n",
+"Tc=(R1*C)/1.44;\n",
+"disp(Tc,'The Circuit Turn Off Time,Tc(micro-sec) = ')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.20_2: state_thyristor_current_and_circuit_turn_off_time.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 1.20.2: Peak Current and turn off time\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"format('v',6)\n",
+"//given data :\n",
+"Vs=200;//in volts\n",
+"R1=10;// in ohm\n",
+"R2=R1;\n",
+"Vc=200;//in volts\n",
+"C=10;// in micro-farad\n",
+"I1=Vs/R1;\n",
+"I2=(Vs+Vc)/R2;\n",
+"It1=I1+I2;\n",
+"disp(It1,'Peak Current,It1(A) = ')\n",
+"Tc=(R1*C)/1.44;\n",
+"disp(Tc,'The Circuit Turn Off Time,Tc(micro-sec) = ')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.21_1: inductance_and_capacitance.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 1.21.1: L and C\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"//given data :\n",
+"V=100;// in volts\n",
+"Irm=40;// in A\n",
+"tq=40;// in micro-sec\n",
+"Del_t=(50/100)*tq;// in micro-sec\n",
+"C=(Irm*(tq+Del_t))/V;\n",
+"disp(C,'capacitance,C(micro-farad) = ')\n",
+"L_min=(V/Irm)^2*C;\n",
+"disp(L_min,'minimum inductance,L_min(micro-Henry) = ')\n",
+"T=2.5;// assume one cycle period in ms\n",
+"L_max=((0.01*(T*10^-3)^2)/(%pi^2*C*10^-6))*10^6;\n",
+"disp(L_max,'Maximum inductance,L_max(micro-Henry) = ')"
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Introduction_to_Electric_Drives_by_J_S_Katre/10-Control_of_AC_drivers.ipynb b/Introduction_to_Electric_Drives_by_J_S_Katre/10-Control_of_AC_drivers.ipynb
new file mode 100644
index 0000000..4d2bcbf
--- /dev/null
+++ b/Introduction_to_Electric_Drives_by_J_S_Katre/10-Control_of_AC_drivers.ipynb
@@ -0,0 +1,166 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 10: Control of AC drivers"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 10.15_1: slip_the_air_gap_power_and_efficiency.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 10.15.1: slip,the air gap power and  efficiency\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"format('v',6)\n",
+"//given data :\n",
+"w=100;// in rad/sec\n",
+"F1=50;//in Hz\n",
+"P=4;\n",
+"Ns=(120*F1)/P;\n",
+"ws=2*%pi*(Ns/60);\n",
+"s=((ws-w)/ws);\n",
+"disp('part (1)')\n",
+"disp('slip is '+string(s)+' or '+string(s*100)+' % ')\n",
+"disp('part (2)')\n",
+"T=100;// in N-M\n",
+"w=100;// in rad/sec\n",
+"Pag=ws*T;\n",
+"P_slip=s*Pag;\n",
+"P_mech=(1-s)*Pag;\n",
+"disp(Pag,'(a)the air gap power,pag(W) = ')\n",
+"disp(P_slip,'(b)slip power(W) =')\n",
+"disp(P_mech,'(c)Mech o/p power,P_mech(W) = ')\n",
+"//air gap power is calculated wrong in the textbook\n",
+"disp('part (3)')\n",
+"eta=(P_mech/Pag);\n",
+"disp('efficiency of the rotor circuit is '+string(eta)+' or '+string(eta*100)+' % ')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 10.15_2: Supply_voltage_per_phase_slip_slip_frequency_slip_and_rotor_los.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 10.15.2 :Supply voltage per phase,slip,slip frequency ,slip and rotor loss\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"//given data :\n",
+"format('v',6)\n",
+"V_rms=240;// in volts\n",
+"F1=50;//in Hz\n",
+"Vs_rms=240/2;\n",
+"disp('part (1)')\n",
+"disp(Vs_rms,'supply voltage (V) = ')\n",
+"disp('part (2)')\n",
+"N=1440;// in rpm\n",
+"P=4;// pole\n",
+"Ns=(120*F1)/4;\n",
+"S=((Ns-N)/Ns);\n",
+"disp('slip is '+string(S)+' or '+string(S*100)+' % ')\n",
+"disp('part (3)')\n",
+"S_frequency=S*F1;\n",
+"disp(S_frequency,'slip frequency(Hz) = ')\n",
+"disp('part (4)')\n",
+"f=2;//Hz\n",
+"f1=25;//Hz\n",
+"s=(f/f1);//\n",
+"disp('slip is '+string(s)+' or '+string(s*100)+' % ')\n",
+"disp('part (5)')\n",
+"F2=25;//in Hz\n",
+"S1=(S_frequency/F2);\n",
+"rotor_loss=S1/(1-S1);\n",
+"disp(rotor_loss ,'Rotor loss(%) = ')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 10.15_6: supply_voltage_slip_slip_frequency_and_percentage_rotor_loss.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 10.15.6: supply voltage per phase , slip ,slip frequency and percentage rotor loss\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"Ns1=750;//\n",
+"V_rms=240;// in volts\n",
+"f2=25;//Hz\n",
+"F1=50;//in Hz\n",
+"Vs_rms=240/2;\n",
+"N=1440;// in rpm\n",
+"P=4;// pole\n",
+"Ns=(120*F1)/4;\n",
+"S=((Ns-N)/Ns);\n",
+"S_frequency=S*F1;\n",
+"fs12=S_frequency/4;//\n",
+"S1=fs12/f2;\n",
+"rotor_loss=S1/(1-S1);\n",
+"n=Ns1-((S1*Ns1));//\n",
+"disp(Vs_rms,'supply voltage (V) = ')\n",
+"disp(S1*100,'slip,S(%) = ')\n",
+"disp(S_frequency,'slip frequency at 50Hz (Hz) = ')\n",
+"disp(fs12,'slip frequency at 25Hz (Hz) = ')\n",
+"disp(rotor_loss ,'Rotor loss(%) = ')\n",
+"disp(n,'speed in rpm is')"
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Introduction_to_Electric_Drives_by_J_S_Katre/11-Appendix_B.ipynb b/Introduction_to_Electric_Drives_by_J_S_Katre/11-Appendix_B.ipynb
new file mode 100644
index 0000000..d59fd3a
--- /dev/null
+++ b/Introduction_to_Electric_Drives_by_J_S_Katre/11-Appendix_B.ipynb
@@ -0,0 +1,107 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 11: Appendix B"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.b: power_absorbed.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Example 2(b): power absorbed\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"vsrms=230;//volts\n",
+"vm=(sqrt(2)*vsrms)/2;//volts\n",
+"alpha=[45:90];//degree\n",
+"x=[(45*(%pi/180));(90*(%pi/180))]\n",
+"for i=1:2\n",
+"    vldc(i)=(vm/%pi)*(1+cosd(alpha(i)));//\n",
+"    vlms(i)=vm*((1/%pi)*(%pi-x(i)+(sin(2*x(i)))/2))^(1/2);//\n",
+"    r1=100;//ohm\n",
+"end\n",
+"r1=100;//OHM\n",
+"pl1=((vlms(1))^2)/r1//W\n",
+"pl2=((vlms(2))^2)/r1;//W\n",
+"disp(pl1,'power aborbed is,(W)=')\n",
+"disp(pl2,'power aborbed is,(W)=')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.b: speed_slip_and_torque.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Example 5(b): power absorbed\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"v=400;//V\n",
+"po=15;//kW\n",
+"nfx=1440;//rpm\n",
+"f=50;//Hz\n",
+"z2=0.4+%i*1.6;//ohm\n",
+"p=4;//\n",
+"x=120;//Hz\n",
+"ns=((x*f)/p);//rpm\n",
+"s=((ns-nfx)/ns);//slip\n",
+"ns1=(x*x)/p;//rpm\n",
+"nfl1=(1-s)*ns1;//rpm\n",
+"disp(nfl1,'full load speed is ,(rpm)=')\n",
+"sm=real(z2)/imag(z2);//slip\n",
+"disp(sm,'slip is,=')\n",
+"tfy=((po*10^3)/(2*%pi*(nfl1/60)));//N-m\n",
+"a=sm;//\n",
+"tm=((a^2+s^2)/(2*a*s))*tfy;//N-m\n",
+"disp(tm,'maximum torque is,(N-m)=')"
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Introduction_to_Electric_Drives_by_J_S_Katre/2-Gate_triggering_Circuits.ipynb b/Introduction_to_Electric_Drives_by_J_S_Katre/2-Gate_triggering_Circuits.ipynb
new file mode 100644
index 0000000..eebde77
--- /dev/null
+++ b/Introduction_to_Electric_Drives_by_J_S_Katre/2-Gate_triggering_Circuits.ipynb
@@ -0,0 +1,553 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 2: Gate triggering Circuits"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.6_1: design_the_triggering_circuit.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 2.6.1;//design\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"//given data :\n",
+"format('v',7)\n",
+"c1=0.1;//in micro farads\n",
+"vbb=30;//in volts\n",
+"n=0.51;//\n",
+"ip=10;//in micro amperes\n",
+"vv=3.5;//in volts\n",
+"iv=10;//in mA\n",
+"f=50;//in Hz\n",
+"w=50;//eifth in micro seconds\n",
+"vd=0.7;//in volts\n",
+"vp=n*vbb+vd;//in volts\n",
+"vc=vp;//in volts\n",
+"x=log(vv/(vp-vd));//\n",
+"r1=-(w*10^-6/(c1*10^-6*x));//\n",
+"T=(1/(f))*10^3;//in ms\n",
+"t1=T-(w*10^-3);// in ms\n",
+"r=((t1*10^-3)/(c1*10^-6*log(1/(1-n))));//\n",
+"r2=(10^4/(n*vbb));//in ohms\n",
+"disp(round(r1),'resistance R1 in ohm is')\n",
+"disp(r*10^-3,'resistance R in kilo ohm is')\n",
+"disp(r2,'resistance R2 in ohm is')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.7_10: desig.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 2.7.10;//design\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"//given data :\n",
+"format('v',6)\n",
+"vs=20;//in volts\n",
+"c1=0.1;//in micro farads\n",
+"vv=2.5;//in volts\n",
+"n=0.66;//\n",
+"ip=10;//in micro amperes\n",
+"iv=10;//in mA\n",
+"f=1;//in KHz\n",
+"tg=40;//in micro seconds\n",
+"vd=0.8;//in volts\n",
+"vp=(n*vs+vd);//in volts\n",
+"r1=((tg*10^-6/(c1*10^-6)));// in ohms\n",
+"r=((1)/(f*10^3*c1*10^-6*log(1/(1-n))))*10^-3;//in killo ohms\n",
+"rmin=(vs-vv)/iv;//minimum resistance in killo ohms\n",
+"rmax=(vs-vp)/ip;//maxium resistance in killo ohms\n",
+"r2=10^4/(n*vs);//in ohms\n",
+"disp(vp,'Vp in volts is')\n",
+"disp(r1,'R1 in ohm is')\n",
+"disp(r,'R in kilo ohm is')\n",
+"disp(rmin,'minimum resistance in kilo ohm is')\n",
+"disp(rmax*10^3,'maximum resistance in kilo ohm is')\n",
+"disp(round(r2),'R2 in ohm is')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.7_11: trigger_angle.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 2.7.11;//trigger angle\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"//given data :\n",
+"format('v',5)\n",
+"vm=120*sqrt(2);//in volts\n",
+"vrb=0.7;//in volts\n",
+"rb=500;//in ohms\n",
+"rl=1000;//in ohms\n",
+"rmin=1000;//in ohms\n",
+"r=4000;//in ohms\n",
+"alpha=asind((0.7*(rl+rmin+r+rb))/(rb*vm));//in degree\n",
+"disp(alpha,'triggering angle in degree is')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.7_12: pulse_width.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 2.7.12;//pulse width\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"//given data :\n",
+"format('v',5)\n",
+"v=200;//in volts\n",
+"il=100;//latch current in mA\n",
+"l=0.2;//inductance in henry\n",
+"dit=v/l;//in amp/sec\n",
+"dt=(il*10^-3)/dit;//in seconds\n",
+"disp('part (a)')\n",
+"disp(dt*10^6,'minimum pulse width required to turn on the SCR is in micro seconds')\n",
+"r=20;//in ohms\n",
+"x=(il*10^-3*r)/v;//\n",
+"t=(log(1-x))*(-l/r);//\n",
+"disp('part (b)')\n",
+"disp(round(t*10^6),'minimum pulse width in micro seconds is')\n",
+"//part b answer is calculated wrong in the textbook"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.7_13: design_the_triggering_circuit.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 2.7.13;//design\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"format('v',6)\n",
+"vs=30;//in volts\n",
+"n=0.51;//\n",
+"vd=0.7;//in volts\n",
+"vp=(n*vs+vd);//in volts\n",
+"c=0.1;//in micro farads\n",
+"vv=3.5;//in volts\n",
+"x=log(vv/(vp-vd));//\n",
+"t2=50;//in micro seconds\n",
+"r3=-((t2*10^-6)/(x*c*10^-6));//in ohms\n",
+"f=50;//in Hz\n",
+"t=(1/f)*10^3;//in ms\n",
+"t1=(t-(t2*10^-6));//inms\n",
+"x1=log(1-((vp-vv)/(vs)));//\n",
+"y1=(-t1*10^-3)/(c*10^-6);//\n",
+"r1=y1/x1;//in ohms\n",
+"r2=(10^4)/(n*vs);//in ohms\n",
+"disp(r1*10^-3,'R1 in ohm is')\n",
+"disp(r2,'R2 in ohm is')\n",
+"disp(round(r3),'R3 in ohm is')\n",
+"disp(c,'capaictance in micro Farad is')\n",
+"//R3 is wrong in the textbook"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.7_1: load_current.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 2.7.1;//current\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"//given data :\n",
+"format('v',3)\n",
+"v=100;//in volts\n",
+"r=20;//in ohms\n",
+"t=50;//in micro seconds\n",
+"l=0.5;//in henry\n",
+"il=(v/r)*(1-exp(-t*10^-6*(r/l)));//\n",
+"disp('load current in (mA) '+string(il*10^3)+'')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.7_2: minimum_width_of_gate_pulse.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 2.7.2;//MINIMUM WIDTH\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"//given data :\n",
+"format('v',7)\n",
+"v=100;//in volts\n",
+"r=20;//in ohms\n",
+"l=0.5;//in henry\n",
+"il=50;//in mA\n",
+"t1=log(1-((il*10^-3)/(v/r)))/(-(r/l));//\n",
+"disp(t1*10^6,'minimum pulse width in micro seconds is')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.7_3: minimum_width_of_gate_pulse.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 2.7.3;//MINIMUM WIDTH\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"//given data :\n",
+"format('v',7)\n",
+"v=207;//in volts\n",
+"r=10;//in ohms\n",
+"l=1;//in henry\n",
+"il=100;//in mA\n",
+"t1=log(1-((il*10^-3)/(v/r)))/(-(r/l));//\n",
+"disp(t1*10^6,'minimum pulse width in micro seconds is')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.7_4: resistance_and_duty_cycle.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 2.7.4;//resistance and duty cycle\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"//given data :\n",
+"format('v',7)\n",
+"vr=15;//in volts\n",
+"t=20;//in micro seconds\n",
+"pd=0.3;//power dissipation in watts\n",
+"Ig=poly(0,'Ig');\n",
+"p=-5+Ig+10*Ig^2;//\n",
+"x=roots(p);//\n",
+"rg=(vr-(1+10*x(2,1)))/(x(2,1));//resistance in ohms\n",
+"disp('part (a)')\n",
+"disp(rg,'resistance Rg in ohm is')\n",
+"pgm=5;//peak power in watts\n",
+"d=(pd/pgm)*100;//duty cycle \n",
+"disp('part (b)')\n",
+"disp(d,'duty cycle in percentage is')\n",
+"tt=(t)/(d/100);//in micro seconds\n",
+"f=(1/(tt*10^-3));//triggering frequency in kHz\n",
+"disp('part (c)')\n",
+"disp(f,'triggering frequency in kHz is')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.7_5: gate_source_resistance.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 2.7.5;//resistance\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"//given data :\n",
+"format('v',4)\n",
+"vg=15;//in volys\n",
+"vgk=0.7;//in volts\n",
+"pg=0.5;// in watts\n",
+"ig=pg/vgk;//in amperes\n",
+"rg=(vg-vgk)/ig;//in ohms\n",
+"disp(rg,'gate source resistance in ohm ')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.7_6: resistance_and_frequency.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 2.7.6;//resistance ,frequency\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"//given data :\n",
+"format('v',6)\n",
+"li=3.7;//leakage current in mA\n",
+"c1=0.1;//in micro farads\n",
+"vp=16;//in volts\n",
+"vv=1;//in volts\n",
+"n=0.7;//\n",
+"ip=0.7;//in milli amperes\n",
+"iv=6;//in mA\n",
+"f=1000;//in Hz\n",
+"rb1=5.5;//in killo ohms\n",
+"t=(1/f)*10^3;//in ms\n",
+"tg=50;//in micro seconds\n",
+"r2=((tg*10^-6/(c1*10^-6)));// in ohms\n",
+"r1=500 ;//in ohms assume\n",
+"vs=(r1+(rb1*10^3)+r2)*(li*10^-3);//in volts\n",
+"r=((t*10^-3)/(c1*10^-6*log(1/(1-n))))*10^-3;//in killo ohms\n",
+"rmin=(vs-vv)/iv;//minimum resistance in killo ohms\n",
+"rmax=(vs-vp)/ip;//maxium resistance in killo ohms\n",
+"fmin=(1/(rmax*10^3*c1*10^-6*log(1/(1-n))));//minimum frequency in Hz\n",
+"fmax=(1/(rmin*10^3*c1*10^-6*log(1/(1-n))))*10^-3;//minimum frequency in Hz\n",
+"disp(vs,'Voltage is ,(V)=')\n",
+"disp(r,'charging resistance in kilo ohm is')\n",
+"disp(rmin,'minimum resistance in kilo ohm is')\n",
+"disp(rmax,'maximum resistance in kilo ohm is')\n",
+"disp(fmin,'minimum frequency is Hz is')\n",
+"disp(fmax,'maximum frequency in kHz is')\n",
+"//mimimum frequency is calculated wrong in the textbook\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.7_7: resistance.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 2.7.7;//resistance\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"//given data :\n",
+"format('v',4)\n",
+"il=50;//in mA\n",
+"pw=50;//pulse width in micro seconds\n",
+"i=10;//in mA\n",
+"v=100;//in volts\n",
+"if1=50;//in mA\n",
+"rmax=(v/(if1-i));//maximum resistance in killo ohms\n",
+"disp(rmax,'maximum resistance in kilo ohm is')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.7_8: resistance_and_gate_power_dissipation_and_frequency.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 2.7.8;//resistance and gate power dissipation and frequency\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"//given data :\n",
+"format('v',7)\n",
+"g=16;//in volts/ampere\n",
+"vr=15;//in volts\n",
+"t=4;//in micro seconds\n",
+"ig=500;//in mA\n",
+"rg=(vr/(ig*10^-3))-g;//resistance in ohms\n",
+"disp('part (a)')\n",
+"disp(rg,'resistance in series with SCR gate in ohm is')\n",
+"ig=500;//in mA\n",
+"rg=(vr/(ig*10^-3))-g;//resistance in ohms\n",
+"pg=(ig*10^-3)^2*(g);//\n",
+"disp('part (b)')\n",
+"disp(pg,'gate power dissipation in Watt is')\n",
+"ogv=0.3;//in watts\n",
+"d=(ogv/pg)*100;//\n",
+"t1=(t)/(d/100);//in micro seconds\n",
+"f1=(1/(t1*10^-3));//frequency in kHz \n",
+"disp('part (c)')\n",
+"disp(f1,'triggering frequency in kHz is')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.7_9: series_resistance.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 2.7.9;//series resistance and power dissipation\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"//given data :\n",
+"format('v',7)\n",
+"vr=12;//in volts\n",
+"t=50;//in micro seconds\n",
+"d=0.2;//duty cycle\n",
+"pd=5;//power dissipation in watts\n",
+"Ig=poly(0,'Ig');\n",
+"p=-5+1.5*Ig+8*Ig^2;//\n",
+"x=roots(p);//\n",
+"rg=(vr-(1.5+8*x(2,1)))/(x(2,1));//resistance in ohms\n",
+"pg=d*pd;//average power loss in watts\n",
+"disp(round(rg),'resistance Rg in ohm is')\n",
+"disp(pg,'average power loss in Watt is')"
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Introduction_to_Electric_Drives_by_J_S_Katre/3-Single_phase_controlled_rectifiers.ipynb b/Introduction_to_Electric_Drives_by_J_S_Katre/3-Single_phase_controlled_rectifiers.ipynb
new file mode 100644
index 0000000..739a92b
--- /dev/null
+++ b/Introduction_to_Electric_Drives_by_J_S_Katre/3-Single_phase_controlled_rectifiers.ipynb
@@ -0,0 +1,522 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 3: Single phase controlled rectifiers"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.3_1: EX3_3_1.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Example 3.3.1: form factor,ripple factor ,transformation utilization factor and peak inverse voltage\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"Vm=1;//assume\n",
+"R=1;//assume\n",
+"t=%pi/3:%pi;\n",
+"Vldc= ((Vm/(2*%pi))*intsplin(t,sin(t)));//\n",
+"Vlms=sqrt((Vm^2/(2*%pi))*intsplin(t,(sin(t))^2));//\n",
+"ff=Vlms/Vldc;\n",
+"disp('part (a)')\n",
+"disp('form factor is '+string(ff)+' or '+string(ff*100)+' percentage')\n",
+"//form factor is calculated wrong in the textbook\n",
+"disp('part (b)')\n",
+"rf=sqrt(ff^2-1);//\n",
+"disp('ripple factor is '+string(rf)+ ' or '+string(rf*100)+' percentage')\n",
+"//ripple factor is calculated wrong in the textbook\n",
+"Vs=Vm/(sqrt(2));//rms secondary voltage\n",
+"Is=Vlms/R;//\n",
+"TUF=((Vldc^2)/R)/(Vs*Is);//\n",
+"disp('part (c)')\n",
+"disp('transformation utilization factor is '+string(TUF)+ ' or '+string(TUF*100)+' percentage')\n",
+"//transformation utilization factor is calculated wrong in the textbook\n",
+"R=1;//assume\n",
+"Vm=1;//assume\n",
+"disp('part (d)')\n",
+"disp('PIV=Vm')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.4_1: plot_the_variatio.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Example 3.4.1: plot the variation\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"vsrms=230;//volts\n",
+"vm=sqrt(2)*vsrms;//volts\n",
+"alpha=[0;30;60;90;120;150;180];//degree\n",
+"x=[0;(30*(%pi/180));(60*(%pi/180));(90*(%pi/180));(120*(%pi/180));(150*(%pi/180));(180*(%pi/180))]\n",
+"for i=1:7\n",
+"    vldc(i)=(vm/%pi)*(1+cosd(alpha(i)));//\n",
+"    vlms(i)=vsrms*((1/%pi)*(%pi-x(i)+(sin(2*x(i)))/2))^(1/2);//\n",
+"end\n",
+"subplot(1,2,1)\n",
+"xlabel('alpha');//\n",
+"ylabel('Vldc');//\n",
+"xtitle('(a) Variation of average load voltage')\n",
+"plot(alpha,vldc);//\n",
+"subplot(1,2,2)\n",
+"xlabel('alpha');//\n",
+"ylabel('Vlrms');//\n",
+"xtitle('(b) Variation of RMS load voltage')\n",
+"plot(alpha,vlms);//"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.4_5: delay_angle_average_output_current_average_and_rms_thyristor_current.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Example 3.4.5: delay angle,rms , averae output current ,average and rms thyristor current\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"format('v',5)\n",
+"Vrms=120;//RMS VOLTAGE \n",
+"R=10;//in ohms\n",
+"Vldc= (0.25*(2*sqrt(2)*Vrms))/%pi;//in volts\n",
+"csd= (Vldc*%pi)/(sqrt(2)*Vrms);//\n",
+"alpha= acosd(csd-1);//\n",
+"disp('part (a)')\n",
+"disp(alpha,'delay angle in degree is')\n",
+"Vrms=120;//RMS VOLTAGE \n",
+"Vm=sqrt(2)*Vrms;//assume\n",
+"t=2*%pi/3:%pi;\n",
+"Vlms=((Vm/(sqrt(2)))*(((1/%pi)*((%pi-(2*%pi)/3)+sind((4*%pi)/6))))^(1/2));\n",
+"Vldc= (0.25*(2*sqrt(2)*Vrms))/%pi;//in volts\n",
+"Ildc=Vldc/R;//average load current in ampere\n",
+"Ilms=Vlms/R;// rms load current in ampere\n",
+"disp('part (b)')\n",
+"disp(Ilms,'rms load current in amperes')\n",
+"disp(Ildc,'average load current in amperes')\n",
+"//rms load current is calculated  wrong in the textbook\n",
+"Im=Vm/R;//\n",
+"Ith=((Im/(2*%pi))*intsplin(t,sin(t)));//in amperes\n",
+"Ithrms=sqrt((Im^2/(2*%pi))*intsplin(t,(sin(t))^2));//in amperes\n",
+"disp('part (c)')\n",
+"disp(Ith,'average thyristor current in amperes is')\n",
+"disp(Ithrms,'rms thyristor current in amperes is')\n",
+"//average and rms thyrister current is calculated wrong in the textbook\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.6_1: EX3_6_1.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Example 3.6.1: average load voltage,rms load voltage,average and rms load currents ,form factor and ripple factor\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"format('v',7)\n",
+"R=10;//IN OHMS\n",
+"r=10;//IN OHMS\n",
+"Vi=230;//in volts\n",
+"alpha=60;//fiirng angle in degree \n",
+"Vm=Vi*sqrt(2);//in voltas\n",
+"Vldc=((Vm)/%pi)*(1+cosd(alpha));//average load voltgae\n",
+"disp('part (a)')\n",
+"disp(Vldc,'average load voltage in volts')\n",
+"disp('part (b)')\n",
+"r=10;//IN OHMS\n",
+"Vi=230;//in volts\n",
+"alpha=60;//fiirng angle in degree \n",
+"Vm=Vi*sqrt(2);//in voltas\n",
+"Vlms=((Vm/(sqrt(2)))*(((%pi-%pi/3)+(sind(2*%pi/3))/2)/%pi)^(1/2));//\n",
+"disp(Vlms,'rms load voltage in volts')\n",
+"//rms voltage is calculated wrong in the textbook\n",
+"disp('part (c)')\n",
+"Ildc=Vldc/R;// in amperes\n",
+"Irms=Vlms/R;// in amperes\n",
+"disp(Irms,'rms load current in ampere')\n",
+"disp(Ildc,'average load current in ampere')\n",
+"//rms load current is wrong in the textbook\n",
+"disp('part (d)')\n",
+"ff=Vlms/Vldc;\n",
+"disp('form factor is '+string(ff)+' or '+string(ff*100)+' %')\n",
+"rf=sqrt(ff^2-1);//\n",
+"disp('ripple factor is '+string(rf)+ ' or '+string(rf*100)+' %')\n",
+"//form factor and ripple factor is calculated wrong in the textbook"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.7_1: device_rating.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Example 3.7.1:device ratings\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"Io=25;//in amperes\n",
+"Vsrms=120;// in colts\n",
+"Vm=sqrt(2)*Vsrms;// in volts\n",
+"for i= 1:5\n",
+"    alpha=[0;60;90;135;180]\n",
+"    Vldc(i)=((Vm)/%pi)*(1+cosd(alpha(i,1)));//\n",
+"    disp(round((Vldc(i))),'mean voltage in volts is at angle '+string(alpha(i,1))+' degree')\n",
+"end\n",
+"PIV=Vm;//peak inverse voltage\n",
+"Iascr=Io/2;//scr average currentin ampere\n",
+"Iadod=Io;//average diode current in amperes\n",
+"Ipscr=Iascr;//peak current rating for SCR in amperes\n",
+"Ipdod=Iadod;//peak current rating for diode in amperes\n",
+"disp(Iascr,'scr average current in amperes')\n",
+"disp(Iadod,'average diode current in amperes')\n",
+"disp(Ipscr,'peak current rating for SCR in amperes')\n",
+"disp(Ipdod,'peak current rating for diode in amperes')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.7_2: Vldc_Vn_Vlrms_HF_DF_and_PF.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Example 3.7.2:Vldc,Vn,Vlrms,HF,DF and PF\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"format('v',7)\n",
+"Vsrms=120;//in volts\n",
+"alpha=%pi/2;//\n",
+"vm=sqrt(2)*Vsrms;//\n",
+"vldc=((sqrt(2)*Vsrms)/(%pi))*(1+cos(alpha));//in volts\n",
+"vldcm=(2*vm)/(%pi);//in volts\n",
+"vn=vldc/vldcm;//normalised average output voltage in volts\n",
+"x=((1/%pi)*((%pi-alpha)+(sin((2*alpha)))/2))^(1/2);//\n",
+"vlrms=((vm/sqrt(2))*x);//RMS load voltage in volts\n",
+"Io=1;//assume\n",
+"Isrms=Io*(1-(alpha/%pi))^(1/2);//in amperes\n",
+"Is1rms=((2*sqrt(2))*Io*cos(alpha/2))/(%pi);//in amperes\n",
+"HF=((Isrms/Is1rms)^2-1)^(1/2);//Harmonic Fator is\n",
+"DF=cos(alpha/2);//Displacement factor\n",
+"PF=(Is1rms/Isrms)*(DF);//power factor\n",
+"disp(round(vldc),'average output voltage (Vldc)in volts is')\n",
+"disp(vn,'Normalised average output voltage (Vn) in volts is')\n",
+"disp(vlrms,'RMS load voltage (Vlrms) in volts is')\n",
+"disp(HF*100,'Harmonic factor (HF) in percentage is')\n",
+"disp(DF*100,'Displacement factor (DF) in percentage is')\n",
+"disp(PF,'power factor (PF) lagging is')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.7_3: amlitude_of_first_four_harmonic_components.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Example 3.7.3:amlitude of first four harmonic components\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"format('v',7)\n",
+"io=1;//assume\n",
+"alpha=%pi/2;//\n",
+"n=[0;0;(1/(%pi*3));0;(1/(%pi*5));0;(1/(%pi*7));0;(1/(%pi*9))];//\n",
+"for i= [3;5;7;9]\n",
+"    m(i)=((2*sqrt(2))*cos(((i)*alpha)/2));\n",
+"end\n",
+"x=[0;0;m(3)*n(3);0;m(5)*n(5);0;m(7)*n(7);0;m(9)*n(9)];//\n",
+"for i=[3;5;7;9]\n",
+"    disp('RMS value of '+string(i)+' harmonic is I'+string((i))+'  = '+string(x(i))+'Io ')\n",
+"end"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.7_4: Vldc_FPF_and_PF.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Example 3.7.4:Vldc,FPF and PF\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"format('v',4)\n",
+"disp('part (a)')\n",
+"vm=1;//assume\n",
+"alpha=[0;30;60;90;120;150;180];//in degree\n",
+"for i=1:7\n",
+"    vldc(i)=(vm/%pi)*(1+cosd(alpha(i)));//\n",
+"    disp('average load voltage (Vldc) for angle '+string(alpha(i))+' degree is Vm*'+string(vldc(i))+' ')\n",
+"end\n",
+"subplot (2,2,1)\n",
+"plot2d(alpha,vldc);//\n",
+"xlabel('alpha(degrees)')\n",
+"ylabel('average voltage (Vldc)')\n",
+"xtitle('(a) Variation of Vldc Vs alpha')\n",
+"disp('part (b)')\n",
+"format('v',6)\n",
+"vm=1;//assume\n",
+"alpha=[0;30;60;90;120;150;180];//in degree\n",
+"for i=1:7\n",
+"     FPF(i)=cosd((alpha(i))/2)\n",
+"     disp('displavefactor or fundamental power factor (FPF) for fringle angle '+string(alpha(i))+' degree is '+string(FPF(i))+' ')\n",
+"end\n",
+"subplot (2,2,2)\n",
+"plot2d(alpha,FPF);//\n",
+"xlabel('alpha(degrees)')\n",
+"ylabel('FPF')\n",
+"xtitle('(b) Variation of FPF Vs alpha')\n",
+"disp('part (c)')\n",
+"vm=1;//assume\n",
+"alpha1=[0;30;60;90;120;150;180];//\n",
+"alpha=[0;%pi/6;%pi/3;%pi/2;(2*%pi)/3;(5*%pi)/6;%pi];//in degree\n",
+"for i=1:6           \n",
+"    \n",
+"     PF(i)=(sqrt(2)*(1+cos(alpha(i))))/sqrt((%pi)*(%pi-alpha(i))) ;\n",
+"     PF(7)=0;//\n",
+"     disp('displavefactor or fundamental power factor (FPF) for fringle angle '+string(alpha1(i))+' degree is '+string(PF(i))+' ')\n",
+"end\n",
+"subplot (2,2,3)\n",
+"plot2d(alpha1,PF);//\n",
+"xlabel('alpha(degrees)')\n",
+"ylabel('FPF')\n",
+"xtitle('(c) Variation of PF Vs alpha')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.7_5: alpha.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Example 3.7.5;alpha\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"format('v',4)\n",
+"disp('part (a)')\n",
+"vc=135;//in volts\n",
+"vs=220;//in vlts\n",
+"rl=0.5;//in ohms\n",
+"io=10;//in ampeeres\n",
+"vm=sqrt(2)*vs;//\n",
+"vldc=io*rl+vc;//\n",
+"alpha=acosd((vldc*%pi)/(2*vm));//\n",
+"disp('alpha is in degree '+string(alpha)+' ')\n",
+"disp('part (b)')\n",
+"vc=145;//in volts\n",
+"vs=220;//in vlts\n",
+"rl=0.5;//in ohms\n",
+"io=10;//in ampeeres\n",
+"vm=sqrt(2)*vs;//\n",
+"vldc=io*rl-vc;//\n",
+"alpha=acosd((vldc*%pi)/(2*vm));//\n",
+"disp('alpha  in degree '+string(alpha)+' ')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.7_6: EX3_7_6.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Example 3.7.6:average output voltage,supply rms current ,supply fundamental current current,displacement factor,supply factor and supply harmonic factor\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"format('v',6)\n",
+"Vsrms=220;//in volts\n",
+"alpha=%pi/3;//\n",
+"vm=sqrt(2)*Vsrms;//\n",
+"vldc=((2*vm)/(%pi))*(cos(alpha));//in volts\n",
+"vldcm=(2*vm)/(%pi);//in volts\n",
+"vn=vldc/vldcm;//normalised average output voltage in volts\n",
+"x=((1/%pi)*((%pi-alpha)+(sin((2*alpha)))/2))^(1/2);//\n",
+"vlrms=((vm/sqrt(2))*x);//RMS load voltage in volts\n",
+"Io=1;//assume\n",
+"Isrms=Io*(1-(alpha/%pi))^(1/2);//in amperes\n",
+"Is1rms=((2*sqrt(2))*Io*cos(alpha/2))/(%pi);//in amperes\n",
+"HF=((Isrms/Is1rms)^2-1)^(1/2);//Harmonic Fator is\n",
+"DF=cos(alpha/2);//Displacement factor\n",
+"PF=(Is1rms/Isrms)*(DF);//power factor\n",
+"disp('part (a)')\n",
+"disp(round(vldc),'average output voltage (Vldc)in volts is')\n",
+"disp('part (b)')\n",
+"disp('due to exact 50% duty cycle the rms value of supply current Isrms=Io')\n",
+"Io=1;//assume\n",
+"Isrms=Io;//in amperes\n",
+"Is1rms=((2*sqrt(2))*Io)/(%pi);//in amperes\n",
+"disp('part (c)')\n",
+"disp('supply fundamental current is '+string(Is1rms)+' Io ')\n",
+"disp('part (d)')\n",
+"DF=cos(alpha);//\n",
+"disp(DF,'displacement factor is')\n",
+"disp('part (a)')\n",
+"SPF=Is1rms*DF;//\n",
+"disp(SPF,'supply power factor is (lagging)')\n",
+"disp('part (f)')\n",
+"HF=(((Isrms/Is1rms)^2)-1)^(1/2);//\n",
+"disp(HF*100,'supply harmonic factor in percentage is')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.7_7: amplitude_of_the_first_three_lower_order_harmonics.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"// Example 3.7.7:amlitude of first three harmonic components\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"format('v',6)\n",
+"io=1;//assume\n",
+"n=[0;0;3*%pi;0;5*%pi;0;%pi*7]\n",
+"for i= [3;5;7]\n",
+"    m(i)=((2*sqrt(2))*io);\n",
+"end\n",
+"x=[0;0;m(3)/n(3);0;m(5)/n(5);0;m(7)/n(7);];//\n",
+"for i=[3;5;7]\n",
+"    disp('RMS value of '+string(i)+' harmonic is I'+string((i))+'  = '+string(x(i))+'Io ')\n",
+"end"
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Introduction_to_Electric_Drives_by_J_S_Katre/4-Three_phase_controlled_rectifiers.ipynb b/Introduction_to_Electric_Drives_by_J_S_Katre/4-Three_phase_controlled_rectifiers.ipynb
new file mode 100644
index 0000000..dc4fbad
--- /dev/null
+++ b/Introduction_to_Electric_Drives_by_J_S_Katre/4-Three_phase_controlled_rectifiers.ipynb
@@ -0,0 +1,60 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 4: Three phase controlled rectifiers"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 4.8_2: current.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 4.8.2: current\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"io=1;//assume\n",
+"t0=0;//\n",
+"t1=(2*%pi)/3;//\n",
+"th=integrate('1','t',t0,t1);//\n",
+"th1=(1/(2*%pi))*th;//\n",
+"x=th1^(1/2);//\n",
+"disp('Ithrms is '+string(x)+'*Io')"
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Introduction_to_Electric_Drives_by_J_S_Katre/5-Inverters.ipynb b/Introduction_to_Electric_Drives_by_J_S_Katre/5-Inverters.ipynb
new file mode 100644
index 0000000..4de6b83
--- /dev/null
+++ b/Introduction_to_Electric_Drives_by_J_S_Katre/5-Inverters.ipynb
@@ -0,0 +1,253 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 5: Inverters"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.12_1: EX5_12_1.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 5.12.1: rms output voltage,output power, average and peak currents,peak reverse blocking voltage,THD,DF,harmonic factor and distortion factor of the lowest order harmonic\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"disp('part (a)')\n",
+"format('v',5)\n",
+"v=24;//in volts\n",
+"V=v;//\n",
+"r=3;//in ohms\n",
+"v1rms=(2*v)/(sqrt(2)*%pi);//in volts\n",
+"disp(v1rms,'rms output voltage at fundamental frequency in volts is')\n",
+"disp('part (b)')\n",
+"po=((v/2)^2)/r;//in watts\n",
+"disp(po,'output power in Watt is')\n",
+"disp('part (c)')\n",
+"itav=(v/(4*r));//in amperes\n",
+"itp=((v/2)/r);//in amperes\n",
+"disp(itav,'average transistor current in amperes is')\n",
+"disp(itp,'transistor peak current in amperes is')\n",
+"disp('part (d)')\n",
+"vbr=2*(v/2);//in volts\n",
+"disp(vbr,'peak reverse bloacking voltage in volts is')\n",
+"disp('part (e)')\n",
+"vo=v/2;//\n",
+"THD1=((vo)^2-(v1rms)^2)^(1/2);//in volts\n",
+"THD=THD1/v1rms;//\n",
+"disp(THD*100,'Total Hramonic distortion in percentage is')\n",
+"disp('part (f)')\n",
+"n=[0;0;(1/3);0;(1/5);0;(1/7);0;(1/9);0;(1/11);0;(1/13)];//\n",
+"for i=[3;5;7;9;11;13]\n",
+"    v(i)=(2*V)*((n(i)))/(%pi*sqrt(2));//\n",
+"end\n",
+"x=sqrt((((v(3))/(3^2))^2)+(((v(5))/(5^2))^2)+(((v(7))/(7^2))^2)+(((v(9))/(9^2))^2)+(((v(11))/(11^2))^2)+(((v(13))/(13^2))^2));//\n",
+"DF=x/v1rms;//\n",
+"disp(DF*100,'distortion factor in percentage is')\n",
+"//distortion factor is calculated wrong in the textbook\n",
+"disp('part (g)')\n",
+"HF3=v(3)/v1rms;//\n",
+"DF3=((v(3))/(3^2))/v1rms\n",
+"disp(HF3*100,'HF for the third harmonic in percentage is')\n",
+"disp(DF3*100,'DF the third harmonic in percentage is')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.12_2: EX5_12_2.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 5.12.2: rms output voltage,output power,average and peak currents,peak reverse blocking voltage,THD,DF,harmonic factor and distortion factor of the lowest order harmonic\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"format('v',5)\n",
+"v=48;//in volts\n",
+"V=v;//\n",
+"r=2.4;//in ohms\n",
+"v1rms=(4*v)/(sqrt(2)*%pi);//in volts\n",
+"disp('part (a)')\n",
+"disp(v1rms,'rms output voltage at fundamental frequency in volts is')\n",
+"disp('part (b)')\n",
+"po=((v)^2)/r;//in watts\n",
+"disp(po,'output power in Watt is')\n",
+"disp('part (c)')\n",
+"itav=(v/(r));//in amperes\n",
+"itp=((v/2)/r);//in amperes\n",
+"disp(itp,'average transistor current in amperes is')\n",
+"disp(itav,'transistor peak current in amperes is')\n",
+"disp('part (d)')\n",
+"vbr=2*(v/2);//in volts\n",
+"disp(vbr,'peak reverse bloacking voltage in volts is')\n",
+"disp('part (e)')\n",
+"vo=v;//\n",
+"THD1=((vo)^2-(v1rms)^2)^(1/2);//in volts\n",
+"THD=THD1/v1rms;//\n",
+"disp(THD*100,'Total Hramonic distortion in percentage is')\n",
+"disp('part (f)')\n",
+"n=[0;0;(1/3);0;(1/5);0;(1/7);0;(1/9);0;(1/11);0;(1/13)];//\n",
+"for i=[3;5;7;9;11;13]\n",
+"    v(i)=(2*V)*((n(i)))/(%pi*sqrt(2));//\n",
+"end\n",
+"x=sqrt((((v(3))/(3^2))^2)+(((v(5))/(5^2))^2)+(((v(7))/(7^2))^2)+(((v(9))/(9^2))^2)+(((v(11))/(11^2))^2)+(((v(13))/(13^2))^2));//\n",
+"vorms=0.9\n",
+"DF=x/vorms;//\n",
+"disp(DF*100,'distor factor in percentage is')\n",
+"//distortion factor is calculated  wrong in the textbook\n",
+"disp('part (g)')\n",
+"HF3=2*v(3)/v1rms;//\n",
+"DF3=2*((v(3))/(3^2))/v1rms\n",
+"disp(HF3*100,'HF for the third harmonic in percentage is')\n",
+"disp(DF3*100,'DF the third harmonic in percentage is')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.12_3: amplitude_of_the_first_three_lower_order_harmonics.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 5.12.3: amplitude of the first three lower order harmonis\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"//given data :\n",
+"v=200;//in volts\n",
+"n=[(1/3);(1/5);(1/7)];//\n",
+"for i=1:3\n",
+"    vn(i)=((4*v*n(i))/(sqrt(2)*%pi));//\n",
+"end\n",
+"disp(round(vn(1)),'Rms value of third harmonic component of output voltage in volts is')\n",
+"disp(round(vn(2)),'Rms value of fifth harmonic component of output voltage in volts is')\n",
+"disp((vn(3)),'Rms value of seventh harmonic component of output voltage in volts is')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.12_4: compare_performance.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 5.12.4: amplitude of the first three lower order harmonis\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"//given data :\n",
+"v=200;//in volts\n",
+"n=[(1/3);(1/5);(1/7)];//\n",
+"vo1rms=(2*v)/(sqrt(2)*%pi);//in volts\n",
+"for i=1:3\n",
+"    vn(i)=((2*v*n(i))/(sqrt(2)*%pi));//\n",
+"end\n",
+"disp(round(vo1rms),'Vo1rms for half bridge circuit in volts is')\n",
+"disp(round(vn(1)),'Rms value of third harmonic component for half bridge circuit  in volts is')\n",
+"disp(round(vn(2)),'Rms value of fifth harmonic component for half bridge circuit in volts is')\n",
+"disp((vn(3)),'Rms value of seventh harmonic component for half bridge circuite in volts is')\n",
+"disp('for bridge inverter')\n",
+"vo1rms1=(4*v)/(sqrt(2)*%pi);//in volts\n",
+"for i=1:3\n",
+"    vn1(i)=((4*v*n(i))/(sqrt(2)*%pi));//\n",
+"end\n",
+"disp(round(vo1rms1),'Vo1rms for half bridge circuit in volts is')\n",
+"disp(round(vn1(1)),'Rms value of third harmonic component for bridge inverter circuit  in volts is')\n",
+"disp(round(vn1(2)),'Rms value of fifth harmonic component for half bridge inverter circuit in volts is')\n",
+"disp((vn1(3)),'Rms value of seventh harmonic component for half bridge inverter circuite in volts is')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.3_1: frequency.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 5.3.1: Maximum frequency\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"//given data :\n",
+"T_off=100;// in micro-sec\n",
+"L=40;// in micro-H\n",
+"C=5;// in micro-farad\n",
+"R=4;//in ohm\n",
+"Tr=((2*%pi)/sqrt((1/(C*10^-6*L*10^-6))-(R^2/(4*(L*10^-6)^2))))*10^6;\n",
+"f=(1/(Tr+T_off))*10^3;\n",
+"disp(f,'maximum frequency,f(kHz) = ')"
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Introduction_to_Electric_Drives_by_J_S_Katre/6-Choppers.ipynb b/Introduction_to_Electric_Drives_by_J_S_Katre/6-Choppers.ipynb
new file mode 100644
index 0000000..7198024
--- /dev/null
+++ b/Introduction_to_Electric_Drives_by_J_S_Katre/6-Choppers.ipynb
@@ -0,0 +1,573 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 6: Choppers"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.5_1: average_load_voltage_RMS_load_voltage_Form_factor_and_Ripple_factor.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 6.5.1:average load voltage,RMS load voltage ,Form factor and Ripple factor\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"format('v',6)\n",
+"//given data \n",
+"f=1;//in kHz\n",
+"t=1/f;//in ms\n",
+"d=0.3;//\n",
+"v=200;//\n",
+"vch=2;//in volts\n",
+"vldc=(v-vch)*d;//average load voltage in volts\n",
+"disp('part (a)')\n",
+"disp(vldc,'average load voltage in volts is')\n",
+"disp('part (b)')\n",
+"vlrms=(v-vch)*sqrt(d);//RMS load voltage in volts\n",
+"disp(vlrms,'RMS load voltage in volts is')\n",
+"disp('part (c)')\n",
+"FF=vlrms/vldc;//\n",
+"disp('ripple factor is '+string(FF)+' or '+string(FF*100)+'%')\n",
+"disp('part (d)')\n",
+"rf=sqrt(FF^2-1);//\n",
+"disp('ripple factor is '+string(rf)+' or '+string(rf*100)+'%')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.5_2: chooper_efficiency_input_resistance_and_average_load_curren.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 6.5.2: chooper efficiency,input resistance and average load current\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"format('v',6)\n",
+"//given data \n",
+"r=10;//in ohms\n",
+"f=1;//in kHz\n",
+"t=1/f;//in ms\n",
+"d=0.3;//\n",
+"v=200;//\n",
+"vch=2;//in volts\n",
+"Po=((v-vch)^2)*(d/r);//in watts\n",
+"Pi=((d*v*(v-vch))/r);//in watts\n",
+"cn=Po/Pi;//chopper efficiency\n",
+"disp('part (a)')\n",
+"disp('chopper efficiency is '+string(cn)+' or '+string(cn*100)+'%')\n",
+"disp('part (b)')\n",
+"R1=r/d;//\n",
+"disp(R1,'input resistance in ohm is')\n",
+"disp('part (c)')\n",
+"vldc=59.4;//V\n",
+"r=10;//ohm\n",
+"Ildc=vldc/r;//amp\n",
+"disp(Ildc,'average load current is,(A)=')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.5_3: Duty_Cycle_Average_Load_voltage_and_RMS_Load_Voltage.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 6.5.3: Duty Cycle,Average Load voltage and RMS Load Voltage\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"format('v',6)\n",
+"//given data \n",
+"V=200;// in volts\n",
+"T_on=500*10^-6;\n",
+"f=1*10^3;// in Hz\n",
+"D=T_on*f;\n",
+"disp('part (a)')\n",
+"disp('duty cycle is '+string(D)+' or '+string(D*100)+'%')\n",
+"disp('part (b)')\n",
+"VL_dc=D*V;\n",
+"disp(VL_dc,'Average Load Voltage,(volts) = ')\n",
+"disp('part (c)')\n",
+"VL_rms=sqrt(D)*V;\n",
+"disp(VL_rms,'RMS Load Voltage,VL_rms(volts) = ')\n",
+"//part c answer is calculated wrong in book"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.5_4: plot_the_variatio.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 6.5.4:average load voltage and rms load voltage\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"//given data \n",
+"for i=1:10\n",
+"    sr(i)=i;//\n",
+"    d(1)=0;\n",
+"    d(i+1)=d(i)+0.1;//\n",
+"end\n",
+"for i=1:11\n",
+"    v=1;//\n",
+"    vldc(i)=d(i)*v;//\n",
+"    vlrms(i)=sqrt(d(i))*v;//\n",
+"end\n",
+"X = [sr];\n",
+"Y = [d];\n",
+"Z  = [vldc];\n",
+"U= [vlrms];\n",
+"disp(Z,'Vldc different values of average load voltage are in volts')\n",
+"disp(U,'Vlrms diffent values of RMS load voltage are in volts')\n",
+"plot(d,[vlrms vldc]);\n",
+"xlabel('DUTY CYCLE D')\n",
+"ylabel('Vldc & Vlrms Volts')\n",
+"xtitle('Variation of Vldc and Vlrms with duty cycle D')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.5_5: plot_the_variatio.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 6.5.5:average load voltage and rms load voltage\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"//given data \n",
+"d=[0.1;0.2;0.3;0.4;0.5;0.6;0.7;0.8;0.9;1.0]\n",
+"for i=1:10\n",
+"    FF(i)=(1/sqrt(d(i)))*100;//\n",
+"     RF(i)=(((((FF(i))/100)^2)-1)^(1/2))*100;//\n",
+"end\n",
+"disp(FF,'FF different values of form factor in percentage is')\n",
+"disp(RF,'RF diffent values of ripple factor in percentage is')\n",
+"plot(d,[FF RF]);\n",
+"xlabel('DUTY CYCLE D')\n",
+"ylabel('FF & RF (%)')\n",
+"xtitle('Variation of FF and RF with duty cycle D')\n",
+"hl=legend(['FF %';'RF %']);"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.5_6: EX6_5_6.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 6.5.6: Average output voltage,RMS output voltage,chopper efficiency and Effective input resistance\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"//given data :\n",
+"format('v',6)\n",
+"r=10;//in ohms\n",
+"d=0.3;//\n",
+"v=230;//\n",
+"vch=1.5;//in volts\n",
+"D=80/100;// duty cycle\n",
+"V=220;// in volts\n",
+"Vch=1.5;//in volts\n",
+"VL_dc=D*(V-Vch);\n",
+"disp('part (a)')\n",
+"disp(VL_dc,'Average output voltage,VL_dc(V) = ')\n",
+"disp('part (b)')\n",
+"VL_rms=sqrt(D)*(V-Vch);\n",
+"disp(VL_rms,'RMS output voltage,VL_rms(V) = ')\n",
+"disp('part (c)')\n",
+"Po=((v-vch)^2)*(d/r);//in watts\n",
+"Pi=((d*v*(v-vch))/r);//in watts\n",
+"cn=Po/Pi;//chopper efficiency\n",
+"disp('chopper efficiency is '+string(cn)+' or '+string(cn*100)+'%')\n",
+"disp('part (d)')\n",
+"D=80/100;// duty cycle\n",
+"R=20;//in ohm\n",
+"Ri=R/D;\n",
+"disp(Ri,'Effective input resistance,Ri(ohm) = ')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.5_7: average_output_voltage_and_average_load_current.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 6.5.7.a;average output voltage and current\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"//given data :\n",
+"vs=120;//in volts\n",
+"vb=1;//in volts\n",
+"d=0.33;//\n",
+"rl=10;//in ohms\n",
+"f=200;//in Hz\n",
+"Vldc=d*vs;//\n",
+"Ildc=round(Vldc)/rl;//in amperes\n",
+"disp(round(Vldc),'average/DC output voltage in volts is')\n",
+"disp(Ildc,'average load current in amperes is')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.6_11: value_of_current_limiting_resistor_maximum_and_minimum_duty_cycle.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 6.6.11: value of current limiting resistor ,maximum and minimum duty cycle\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"format('v',6)\n",
+"//given data :\n",
+"v=325;//in volts\n",
+"eb=120;//in volts\n",
+"r=0.2;//in ohms\n",
+"ra=0.3;//in ohms\n",
+"e=120;//in volts\n",
+"rb=0.2;//in ohms\n",
+"rl=0.3;//in ohms\n",
+"d=60;//in percentage\n",
+"i=20;//in amperes\n",
+"vo=(d/100)*v;//\n",
+"R=((i*rl)-(v-eb)+(i*rb))/(-i);//\n",
+"disp('part (a)')\n",
+"disp(R,'value of current limiting resistor in ohm is')\n",
+"//value of current limiting resistor is calculated wrong in the textbook\n",
+"disp('part (b)')\n",
+"p=15;//\n",
+"R=9.45;//\n",
+"vmax=v+(v*(p/100));//\n",
+"vmin=v-(v*(p/100));//\n",
+"Dmax=((i*R)/vmin)*100;//\n",
+"Dmin=((i*R)/vmax)*100;//\n",
+"disp(Dmax,'maximum duty cycle in percentage is')\n",
+"disp(Dmin,'minimum duty cycle in percentage is')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.6_5: average_armature_current.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 6.6.5 : Average armature current\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"//given data :\n",
+"V=200;// in volts\n",
+"D=50/100;// duty cycle\n",
+"VL_dc=V*D;\n",
+"Eb=75;// in volts\n",
+"Ra=1;// in ohm\n",
+"Ia=(VL_dc-Eb)/Ra;\n",
+"disp(Ia,'Average armature current,Ia(A) = ')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.6_6: EX6_6_6.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 6.6.6 :minimum instantaneous load current,peak instantaneous current and maximum peak to peak ripple\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"format('v',6)\n",
+"v=220;//volts\n",
+"r=10;//in ohms\n",
+"l=15.5;//in mH\n",
+"f=5;//in kHz\n",
+"Eb=20;//in volts\n",
+"d=0.5;//\n",
+"x=exp((-(1-d)*r)/(f*10^3*l*10^-3));//\n",
+"y=(1-x)*(Eb/r);//\n",
+"y1=(1-x)*((v-Eb)/r);//\n",
+"A=[0.94 -0.94*0.94;0.94 -1];\n",
+"B=[-0.94*0.125;-1.25];\n",
+"X=A\B;//\n",
+"disp('part (a)')\n",
+"disp(X(1,1),'minimum instantaneous current in amperes is')\n",
+"disp('part (b)')\n",
+"disp(X(2,1),'peak instantaneous current in amperes is')\n",
+"disp('part (c)')\n",
+"PP=X(2,1)-X(1,1);//\n",
+"disp(PP,'maximum peak to peak ripple in the load current in amperes is')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.6_7: load_inductance.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 6.6.7;inductance\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"v=220;//in volts\n",
+"r=0.2;//in ohms\n",
+"ia=200;//in amperes\n",
+"f=200;//in hz\n",
+"di=0.05*ia;//in amperes\n",
+"e=0;//in volts\n",
+"d=0.5;//\n",
+"l=((1-d)*v*d*(1/f))/di;//\n",
+"disp(l*10^3,'inductance in mH is')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.6_9: EX6_6_9.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 6.6.9: load current is continuous or not,Average output current , maximum and minimum steady state output current and  RMS values of first and second harmonics of the load current\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"//given data :\n",
+"format('v',6)\n",
+"V=220;//in volts\n",
+"La=5;// in mH\n",
+"Eb=24;//in volts\n",
+"Ra=1;// in ohm\n",
+"T=2;//in m-sec\n",
+"D=0.6/2;\n",
+"D_dash=(La/(T*Ra))*log(1-((Eb/V)*(1-exp((T*Ra)/La))));\n",
+"disp('part (c)')\n",
+"disp('As D = '+string(D)+'% is greater then D_dash = '+string(D_dash)+'% so load current is continous')\n",
+"disp('part (d)')\n",
+"Io=((D*V)-Eb)/Ra;\n",
+"disp(Io,'Average output current,Io(A) = ')\n",
+"I_max=(V/Ra)*((1-exp(-(D*T*Ra)/La))/(1-exp(-(T*Ra)/La)))-(Eb/Ra);\n",
+"disp(I_max,'Maximum steady state putput current,I_max(A) = ')\n",
+"I_min=(V/Ra)*((1-exp((D*T*Ra)/La))/(1-exp((T*Ra)/La)))-(Eb/Ra);\n",
+"disp(round(I_min),'Minimum steady state output current,I_min(A) = ')\n",
+"disp('part (e)')\n",
+"C1_rms=((2*V)/(%pi*sqrt(2)))*sin(%pi*D);// in volts\n",
+"C2_rms=((2*V)/(2*%pi*sqrt(2)))*sin(2*%pi*D);// in volts\n",
+"Z1=((Ra^2+(2*%pi*La*10^-3*(1/(T*10^-3)))^2)^(1/2));//\n",
+"Z2=((Ra^2+(2*2*%pi*La*10^-3*(1/(T*10^-3)))^2)^(1/2));//\n",
+"Ifl=C1_rms/Z1;//in amperes\n",
+"Ifl1=C2_rms/Z2;//in amperes\n",
+"disp(Ifl,'fundamental component of load current in amperes is')\n",
+"disp(Ifl1,'second harmonic component of load current in amperes is')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.9_1: output_voltage.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 6.9.1 : pulse width and output voltage\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"//given data :\n",
+"v=220;//in volts\n",
+"vo=660;//in volts\n",
+"toff=100;//in micro seconds\n",
+"ton=((vo*toff)/v)-toff;//in micro secondsT=ton+toff;//in micro seconds\n",
+"T=ton+toff;\n",
+"f=(1/T);//in Hz\n",
+"Vo=((v)/(1-(f*(ton/2))));//in volts\n",
+"disp(ton,'pulse width (ton) in micro seconds is')\n",
+"disp(Vo,'new output voltage in volts is')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.9_2: chopping_frequency_and_output_voltage.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 6.9.2 :chopping frequency and new output voltage\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"format('v',8)\n",
+"//given data :\n",
+"v=200;//in volts\n",
+"vo=600;//in volts\n",
+"ton=200;//in micro seconds\n",
+"x=-((v/vo)-1);//\n",
+"f=x/(ton*10^-6);//\n",
+"ton1=ton/2;//\n",
+"Vo=((v)/(1-(f*ton1*10^-6)));//in volts\n",
+"disp(f,'chopping frequency in Hz is')\n",
+"disp(Vo,'new output voltage in volts is')"
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Introduction_to_Electric_Drives_by_J_S_Katre/8-Control_of_DC_drivers.ipynb b/Introduction_to_Electric_Drives_by_J_S_Katre/8-Control_of_DC_drivers.ipynb
new file mode 100644
index 0000000..87c3005
--- /dev/null
+++ b/Introduction_to_Electric_Drives_by_J_S_Katre/8-Control_of_DC_drivers.ipynb
@@ -0,0 +1,665 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 8: Control of DC drivers"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.12_1: back_emf_Required_armature_voltage_and_Rated_armatuer_current.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 8.12.1: back emf ,Required armature voltage and Rated armatuer current\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"//given data :\n",
+"format('v',7)\n",
+"TL=45;// in N-M\n",
+"N=1200;//in rpm\n",
+"Rf=147;//in ohm\n",
+"Ra=25;// in ohm\n",
+"Kv=0.7032;\n",
+"w=(2*%pi*N)/60;\n",
+"Vf=220;//in volts\n",
+"Kt=Kv;\n",
+"If=Vf/Rf;\n",
+"T=TL;\n",
+"Ia=T/(Kt*If);\n",
+"Eg=Kv*w*If;\n",
+"disp('part (a)')\n",
+"disp(Eg,'Back emf,Eg(Volts) = ')\n",
+"disp('part (b)')\n",
+"Ea=(Ia*(Ra/100))+Eg;\n",
+"disp(Ea,'Required armature voltage,Ea(volts) = ')\n",
+"disp('part (c)')\n",
+"rac=11191.4/Vf;//\n",
+"disp(rac,'rated armature current in amperes is')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.12_2: the_field_current_Evaluation_of_alfa_Evaluation_of_power_factor.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 8.12.2: the field current,Evaluation of alfa,Evaluation of power factor\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"//given data :\n",
+"format('v',7)\n",
+"TL=50;// in N-M\n",
+"N=1000;//in rpm\n",
+"Rf=150;//in ohm\n",
+"Ra=.25;// in ohm\n",
+"Kv=0.7032;\n",
+"alfa=0;\n",
+"Vm=230;// in volts\n",
+"Ef=((Vm*sqrt(2))/%pi)*(1+cosd(alfa));\n",
+"If=Ef/Rf;\n",
+"disp('part (a)')\n",
+"disp(If,'Field current,If(A) = ')\n",
+"disp('part (b)')\n",
+"w=(2*%pi*N)/60;\n",
+"Ia=TL/(Kv*If);\n",
+"Eg=Kv*w*If;\n",
+"Ea=Eg+(Ra*Ia);\n",
+"alfa_a=acosd(((Ea*%pi)/(Vm*sqrt(2)))-1);\n",
+"disp(alfa_a,'angle in degree')\n",
+"disp('part (c)')\n",
+"Ismax=Ia*((180-alfa_a)/180)^(1/2);//in amperes\n",
+"PF=((Ea*Ia)/(Vm*Ismax));//lagging\n",
+"disp(PF,'power factor (lagging) is')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.12_3: torque.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 8.12.3: torque  \n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"format('v',7)\n",
+"//given data :\n",
+"Ia=50;// in A\n",
+"Rf=150;//in ohm\n",
+"Ra=.25;// in ohm\n",
+"Kv=1.4;// in V/A-rad/sec\n",
+"alfa_f=0;\n",
+"alfa_a=45;// in degree\n",
+"Vm=230*sqrt(2);// in volts\n",
+"Vs=230;// in volts\n",
+"Ef=((2*Vm)/%pi)*(cosd(alfa_f));\n",
+"If=Ef/Rf;\n",
+"T=Kv*Ia*If;\n",
+"disp('part (a)')\n",
+"disp(T,'Torque developed by the motor,T(N/m) = ')\n",
+"Ea=((2*Vm)/%pi)*(cosd(alfa_a));\n",
+"Eg=Ea-(Ia*Ra);\n",
+"w=Eg/(Kv*If);\n",
+"N=(w/(2*%pi))*60;\n",
+"disp('part (b)')\n",
+"disp(N,'Speed,N(rpm) = ')\n",
+"disp('part (c)')\n",
+"Ea=Eg+(Ra*Ia);\n",
+"alfa_a=acosd(((Ea*%pi)/(Vm*sqrt(2)))-1);\n",
+"Ismax=Ia*((180-alfa_a)/180)^(1/2);//in amperes\n",
+"PF=((Ea*Ia)/(Vm*Ismax));//lagging\n",
+"disp(PF,'power factor (lagging) is')\n",
+"//supply power factor is calculated wrong in the textbook"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.12_4: Motor_torque.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 8.12.4: Motor torque\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"format('v',7)\n",
+"//given data :\n",
+"Vs_rms=230;// in volts\n",
+"N=1200;// in rpm\n",
+"Ia=40;// in A\n",
+"Ra=0.25;//in ohm\n",
+"Ka_fi1=0.182;// in V/rpm\n",
+"Ka_fi=(0.182*60)/(2*%pi);\n",
+"alfa_a=30;\n",
+"T=Ka_fi*Ia;\n",
+"disp('part (a)')\n",
+"disp(T,'Motor torque,T(N-m) = ')\n",
+"disp('part (b)')\n",
+"Ea=((2*sqrt(2)*Vs_rms)/%pi)*(cosd(alfa_a));\n",
+"N=(Ea-(Ra*Ia))/Ka_fi1;\n",
+"disp(N,'Speed of the motor,N(rpm) = ')\n",
+"disp('part (c)')\n",
+"Is_rms=Ia;\n",
+"PF=(Ea*Ia)/(Vs_rms*Is_rms);\n",
+"disp(PF,'Power factor,PF(lagging) = ')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.12_6: draw_characterstics.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 8.12.6;Torque speed charaterstics\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"format('v',7)\n",
+"//given data :\n",
+"v=230;//in volts\n",
+"vm=sqrt(2)*v;//in clts\n",
+"Ka=1;\n",
+"QR=1;//\n",
+"ra=0.05;//\n",
+"alpha=30;//in degree\n",
+"y=(60/(2*%pi));//\n",
+"z=((vm/%pi)*(1+cosd(alpha)));//\n",
+"x=(ra/(0.5)^2)\n",
+"for i=1:8\n",
+"    wm(i)= (z-(i)*x)*y;//\n",
+"end\n",
+"wm=[(y*z);wm(1);wm(2);wm(3);wm(4);wm(5);wm(6);wm(7);wm(8)]\n",
+"disp(wm,'varoius values of speed in RPM is')\n",
+"T=[0;1;2;3;4;5;6;7;8];\n",
+"plot2d(T,wm)\n",
+"xlabel('Torque ,N-m')\n",
+"ylabel('Speed (rpm)  for alpha=30 degree')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.18_1: No_load_speed_firing_angle_Power_Factor_and_speed_regulation.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 8.18.1: No load speed ,firing angle ,Power Factor and speed regulation\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"format('v',6)\n",
+"//given data :\n",
+"Ra=0.075;//in ohm\n",
+"alfa1=0;// in degree\n",
+"alfa2=30;// in degree\n",
+"VL_rms=480;// in volts\n",
+"Ka_fi=0.3;// in V/rms\n",
+"Vs_rms=round(VL_rms/sqrt(3));\n",
+"Vm=sqrt(2)*Vs_rms;\n",
+"Ea=round((3*sqrt(3)*Vm*cosd (alfa1))/%pi);\n",
+"Ea1=((3*sqrt(3)*Vm*cosd(alfa2))/%pi);\n",
+"Ia=(10/100)*160;// in A\n",
+"N_0=(Ea-Ia*Ra)/Ka_fi;\n",
+"N_30=(Ea1-Ia*Ra)/Ka_fi;\n",
+"disp('part (a)')\n",
+"disp(N_0,'No load speed at alfa=0 degree,(rpm) = ')\n",
+"disp(N_30,'No load speed at alfa=30 degree,(rpm) = ')\n",
+"disp('part (b)')\n",
+"Ia=160;// in A\n",
+"N=1800;// in rpm\n",
+"Eg=540;// in volts\n",
+"Ea=(Eg+(Ia*Ra));\n",
+"alfa=(acosd((Ea*%pi)/(3*sqrt(3)*Vm)));\n",
+"disp(alfa,'the firng angel,alfa(degree) = ')\n",
+"disp('part (c)')\n",
+"Is_rms=sqrt(2/3)*Ia;\n",
+"Sva=3*Vs_rms*Is_rms;\n",
+"PF=(Ea*Ia)/(Sva);\n",
+"disp(PF,'Power Factor,PF(lagging) = ')\n",
+"disp('part (d)')\n",
+"Ra=0.075;//in ohm\n",
+"Ia=160;// in A\n",
+"Ia1=16;// in A\n",
+"Eg=540;// in volts\n",
+"Ka_fi=0.3;// in V/rms\n",
+"N=1800;// in rpm\n",
+"Ea=(Eg+(Ia*Ra));\n",
+"Eg1=Ea-(Ia1*Ra);\n",
+"N_0=Eg1/Ka_fi;\n",
+"SR=((N_0-N)/N)*100;\n",
+"disp(SR,'Speed Regulation,SR(%) = ')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.18_2: Delay_Angel_of_Armature_No_load_speed_and_speed_regulation.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 8.18.2: Delay Angel of Armature,No load speed and speed regulation\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"//given data :\n",
+"format('v',5)\n",
+"VL_rms=208;// in volts\n",
+"Kv=1.2;// in V/A-rad/sec\n",
+"Vs_rms=round(VL_rms/sqrt(3));\n",
+"Vm=sqrt(2)*Vs_rms;\n",
+"Rf=240; // in ohm\n",
+"Ra=0.25;// in ohm\n",
+"alfa_f=0;// in degree\n",
+"V=280;// in volts\n",
+"Twenty_HP=20*746;//in watt\n",
+"Ia=Twenty_HP/V\n",
+"Ef=round((3*sqrt(3)*Vm*cosd (alfa_f))/%pi);\n",
+"N=1800;\n",
+"w=(N*2*%pi)/60;\n",
+"If=Ef/Rf;\n",
+"Eg=Kv*w*If;\n",
+"Ea=round(Eg+(Ia*Ra));\n",
+"alfa_a=(acosd((Ea*%pi)/(3*sqrt(3)*Vm)));\n",
+"disp('part (a)')\n",
+"disp(alfa_a,'Delay Angel Of Armature,alfa_a(degree) = ')\n",
+"disp('part (b)')\n",
+"Ia1=(Ia*10)/100\n",
+"Eg_noL=Ea-(Ia1*Ra);\n",
+"w_0=(Eg_noL/(1.2*1.17));// rad/sec\n",
+"N_0=(w_0*60)/(2*%pi);\n",
+"disp(N_0,'NO load speed at alfa|_a,(rpm) = ')\n",
+"// no load speed is calculated wrong in textbook\n",
+"disp('part (c)')\n",
+"SR=((N_0-N)/N)*100;\n",
+"disp(SR,'Speed Regulation,SR(%) = ')\n",
+"// speed regulation is calculated wrong in the textbook"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.18_3: alphas_speed_and_delay_angle.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 8.18.3: alphas,speed and delay angle\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"//given data :\n",
+"format('v',7)\n",
+"v1=208;//\n",
+"vsrms=v1/sqrt(3);//\n",
+"n=1000;//rpm\n",
+"w=n*(%pi/30);//in rad/s\n",
+"ang=0;//\n",
+"ef=((3*sqrt(3)*sqrt(2)*vsrms*cosd(ang))/%pi);//in volts\n",
+"rf=140;//in ohms\n",
+"If=ef/rf;//in amperes\n",
+"t=120;//N-m\n",
+" kv=1.2;//\n",
+"ia=(t)/(kv*If);//in amperes\n",
+"eg=kv*If*w;//in volts\n",
+"ra=0.25;//in ohms\n",
+"ea=eg+(ia*ra);//\n",
+"alpha=acosd((ea*%pi)/(3*sqrt(3)*sqrt(2)*vsrms))\n",
+"disp('part (a)')\n",
+"disp(round(alpha),'alpha in degree is')\n",
+"disp('part (b)')\n",
+"rf=140;//in ohms\n",
+"If=ea/rf;//in amperes\n",
+"t=120;//N-m\n",
+" kv=1.2;//\n",
+"ia=(t)/(kv*If);//in amperes\n",
+"ra=0.25;//in ohms\n",
+"eg=ea-(ia*ra);//\n",
+"w=(eg/(kv*If));//in rad/s\n",
+"N=w*(30/%pi);//rpm\n",
+"disp(N,'speed in rpm is')\n",
+"//speed is calculated wrong in the textbook\n",
+"disp('part (c)')\n",
+"n1=1000;//rpm\n",
+"w=n1*(%pi/30);//in rad/s\n",
+"v1=208;//\n",
+"vsrms=v1/sqrt(3);//\n",
+"w1=(1800*(%pi/30));//\n",
+"n=1800;//rpm\n",
+"ang=0;//\n",
+"T=120;//n-m\n",
+"alphas=0;//\n",
+"ang=0;//\n",
+"ea=((3*sqrt(3)*sqrt(2)*vsrms*cosd(ang))/%pi);//in volts\n",
+"rf=140;//in ohms\n",
+"If=ea/rf;//in amperes\n",
+"t=120;//N-m\n",
+" kv=1.2;//\n",
+"ia=(t)/(kv*If);//in amperes\n",
+"ra=0.25;//in ohms\n",
+"eg=ea-(ia*ra);//\n",
+"if1=eg/(kv*w1);//in amperese\n",
+"ef1=if1*rf;//in volts\n",
+"alphaf=acosd((ef1*%pi)/(3*sqrt(3)*120*sqrt(2)));\n",
+"disp(alphaf,'delay angle in degree is')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.19_1: Firing_angle_to_keep_the_motor_current_and_Power_fed_back.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 8.19.1: Firing angle to keep the motor current and Power fed back \n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"//given data :\n",
+"format('v',7)\n",
+"Vs_rms=260;// in volts\n",
+"Ia=40;// in A\n",
+"Eg=192;//in volts\n",
+"kv=0.182;// in V/rpm\n",
+"Ra=0.3;// in ohm\n",
+"Ea=Eg+(Ia*Ra);\n",
+"alfa_a=acosd((Ea*%pi)/(2*Vs_rms*sqrt(2)));\n",
+"disp('part (a)')\n",
+"disp(alfa_a,'Firing angle to keep motor current,alfa_a(degree) = ')\n",
+"Ea1=-Eg+(Ia*Ra);\n",
+"alfa_b=acosd((Ea1*%pi)/(2*Vs_rms*sqrt(2)));\n",
+"disp(alfa_b,'Firing angle ,alfa_a(degree) =')\n",
+"disp('part (b)')\n",
+"Ia=40;// in A\n",
+"Eg=192;//in volts\n",
+"Ra=0.3;// in ohm\n",
+"Ea=-Eg+(Ia*Ra);\n",
+"P=abs(Ea)*Ia;\n",
+"disp(P,'Power fed back,P(Watt) = ')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.19_2: EX8_19_2.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 8.19.2 Average armature voltage ,back emf ,speed of the motor , motor torque and supply power factor\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"format('v',5)\n",
+"//given data :\n",
+"Vm=230;// in volts\n",
+"Ia=40;// in A\n",
+"Ra=0.5;// in ohm\n",
+"Ka_fi=0.2;// in V/rpm\n",
+"alfa=30;\n",
+"Ea=(Vm*sqrt(2)*(1+cosd(alfa)))/%pi;\n",
+"disp('part (a)')\n",
+"disp(Ea,'Average armature current,Ea(volts) = ')\n",
+"disp('part (b)')\n",
+"Eb=Ea-(Ia*Ra);\n",
+"disp(Eb,'Back emf,Eb(volts) = ')\n",
+"disp('part (c)')\n",
+"N=Eb/Ka_fi;\n",
+"disp(round(N),'Speed of the motor,N(rpm) = ')\n",
+"disp('part (d)')\n",
+"Ka_fi1=(Ka_fi*60)/(2*%pi);\n",
+"T=Ka_fi1*Ia;\n",
+"disp(T,'Torque,T(N/m) = ')\n",
+"disp('part (e)')\n",
+"alfa=%pi/6;\n",
+"PF=(2*sqrt(2)*cos(alfa/2)^2)/(sqrt(%pi*(%pi-alfa)));\n",
+"disp(PF,'power factor (lagging) is')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.19_3: torque_developed_speed_and_input_power_factor.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 8.19.3: torque developed,speed and input power factor\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"//given data :\n",
+"format('v',7)\n",
+"v=208;//in volts\n",
+"f=50;//in Hz\n",
+"ra=0.5;//in ohms\n",
+"rf=345;//in ohms\n",
+"kv=0.71;//in V/A-rad/sec\n",
+"alpha=45;//in degree\n",
+"ia=55;//in amperes\n",
+"If=((2*sqrt(2)*v*cosd(0))/(%pi*rf));//in amperes\n",
+"t=kv*If*ia;//in  N/m\n",
+"disp('part (a)')\n",
+"disp(t,'torque in N/m is')\n",
+"disp('part (b)')\n",
+"eb=((2*sqrt(2)*v*cosd(alpha))/%pi)-(ia*ra);//in volts\n",
+"w=eb/(kv*If);//in rad/sec\n",
+"N=w/(2*%pi);//rps\n",
+"disp(N*60,'speed in rpm')\n",
+"//speed is calculated wrong in the textbook\n",
+"disp('part (c)')\n",
+"ea=132.4;//in volts\n",
+"ef=187.3;//in volts\n",
+"pi=(ea*ia)+(ef*If);//in watts\n",
+"Isrms=sqrt((ia)^2+(If)^2);//in amperes\n",
+"va1=Isrms*v;//in VA\n",
+"Pf=pi/va1;//\n",
+"disp(Pf,'power factor (lagging) is')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.19_4: EX8_19_4.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 8.19.4:develepoed back emf,required armature voltage and firing angle and rated armature current\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"//given data :\n",
+"format('v',6)\n",
+"hp=20;//\n",
+"v=230;//volts\n",
+"n=1000;//rpm\n",
+"lt=50;//load torque in N-m\n",
+"s=1000;//speed in rpm\n",
+"ra=0.2;//in ohms\n",
+"rf=150;//in ohms\n",
+"la=10;//in mH\n",
+"kv=0.7;//\n",
+"vf=(2*sqrt(2)*v)/(%pi);//\n",
+"If=vf/rf;//in amperes\n",
+"ia=(lt/(kv*If));//in amperes\n",
+"eg=((kv*2*%pi*n*If))/(60);//in volts\n",
+"disp('part (a)')\n",
+"disp(eg,'back emf in volts is')\n",
+"disp('part (b)')\n",
+"ea=eg+(ia*ra);//in volts\n",
+"alpha=acosd((ea*%pi)/(2*sqrt(2)*v));//\n",
+"disp(ea,'armature voltage in volts is')\n",
+"disp(alpha,'firing angle in degree is')\n",
+"disp('part (c)')\n",
+"ea1=220;//in volts\n",
+"ha20=746*20;//\n",
+"iar=(ha20/ea1);//in amperes\n",
+"disp(iar,'rated armature current in amperes is')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.21_1: average_armature_current.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 8.21.1 : Average armature current\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"//given data :\n",
+"V=200;// in volts\n",
+"D=50/100;// duty cycle\n",
+"VL_dc=V*D;\n",
+"Eb=75;// in volts\n",
+"Ra=1;// in ohm\n",
+"Ia=(VL_dc-Eb)/Ra;\n",
+"disp(Ia,'Average armature current,Ia(A) = ')"
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Introduction_to_Electric_Drives_by_J_S_Katre/9-Power_factor_improvement.ipynb b/Introduction_to_Electric_Drives_by_J_S_Katre/9-Power_factor_improvement.ipynb
new file mode 100644
index 0000000..567141e
--- /dev/null
+++ b/Introduction_to_Electric_Drives_by_J_S_Katre/9-Power_factor_improvement.ipynb
@@ -0,0 +1,207 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 9: Power factor improvement"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.4_3: plot_the_variatio.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 9.4.3:plot the varaition of average load voltage with firing angle\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"alpha=[0;30;60;90];//firing angle in degree\n",
+"for i=1:4\n",
+"    ea(i)=(2/%pi)*cosd(alpha(i));//V\n",
+"end\n",
+"plot2d(alpha,ea);//\n",
+"ylabel('Average load voltage(in terms of Vm)')\n",
+"xlabel('Firing angle (alpha)')\n",
+"xtitle('Variation of Ea Vs alpha for SAC')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.5_1: ISrms_I1rms_FPF_PF_and_HF.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 9.5.1; IS_rms, I1_rms, FPF, PF and HF\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"format('v',7)\n",
+"//given data :\n",
+"Vm=230;// in volts\n",
+"Ia=12;// in A\n",
+"pi=180;\n",
+"Av=200;// average load voltage in volts\n",
+"alfa=acosd(((Av*%pi)/(Vm*sqrt(2)))-1);\n",
+"Is_rms=Ia*sqrt((pi-alfa)/pi);\n",
+"disp( '(a)for PAC')\n",
+"disp(Is_rms,'(1) Is_rms(A) = ')\n",
+"I1_rms=((2*sqrt(2))/%pi)*Ia*cosd(alfa/2);\n",
+"disp(I1_rms,'(2) I1_rms(A) = ')\n",
+"fi=alfa/2;\n",
+"FPF=cosd(fi);\n",
+"disp(FPF,'(3) FPF(lag) = ')\n",
+"CDF=I1_rms/Is_rms;\n",
+"disp(CDF,'(4) CDF = ')\n",
+"PF=CDF*FPF;\n",
+"disp(PF,'(4) PF (lag)= ')\n",
+"HF=sqrt((1/CDF^2)-1);\n",
+"disp(HF,'(5) HF = ')\n",
+"Vm=230;// in volts\n",
+"Ia=12;// in A\n",
+"pi=180;\n",
+"Av=200;// average load voltage in volts\n",
+"alfa=acosd(((Av*%pi)/(2*Vm*sqrt(2))));\n",
+"Is_rms=Ia*sqrt((pi-(2*alfa))/pi);\n",
+"disp( '(b)for SAC')\n",
+"disp(Is_rms,'(1) Is_rms(A) = ')\n",
+"I1_rms=((2*sqrt(2))/%pi)*Ia*cosd(alfa);\n",
+"disp(I1_rms,'(2) I1_rms(A) = ')\n",
+"fi=0;\n",
+"FPF=cosd(fi);\n",
+"disp(FPF,'(3) FPF = ')\n",
+"CDF=I1_rms/Is_rms;\n",
+"disp(CDF,'(4) CDF = ')\n",
+"//in book CDF is mentioned as DF which is wrongly mentioned\n",
+"PF=CDF*FPF;\n",
+"disp(PF,'(4) PF (lagging)= ')\n",
+"HF=(sqrt((1/CDF^2)-1))*100;\n",
+"disp(HF,'(5) HF (%) = ')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.5_2: parameters_amd_average_voltage.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 9.5.2;average voltage \n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"format('v',7)\n",
+"a1=30;//in degree\n",
+"a2=75;//in degree\n",
+"b1=60;//in degree\n",
+"ia=10;//in amperes\n",
+"vsrms=230;//in volts\n",
+"b3=180-a1;//\n",
+"a3=180-b1;//\n",
+"b2=180-a2;//\n",
+"alfa=0;//\n",
+"vldc=((vsrms*sqrt(2))/%pi)*(cosd(a1)-cosd(b1)+cosd(a2)-cosd(b2)+cosd(a3)-cosd(b3));//\n",
+"disp(vldc,'average voltage in volts is')\n",
+"Is_rms=ia*((1/180)*(b1-a1+b2-a2+b3-a3))^(1/2);//\n",
+"disp(Is_rms,' Is_rms(A) = ')\n",
+"I1_rms=((sqrt(2)*ia)/(%pi))*(cosd(a1)-cosd(b1)+cosd(a2)-cosd(b2)+cosd(a3)-cosd(b3));//\n",
+"disp(I1_rms,' I1_rms(A) = ')\n",
+"fi=alfa;\n",
+"FPF=cosd(fi);\n",
+"disp(FPF,'FPF = ')\n",
+"DF=I1_rms/Is_rms;\n",
+"disp(DF,' DF = ')\n",
+"PF=DF*FPF;\n",
+"disp(PF,' PF(lag)= ')\n",
+"HF=sqrt((1/DF^2)-1);\n",
+"disp(HF*100,' HF(%) = ')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.5_3: parameters.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 9.5.3: IS_rms, I1_rms, PF and HF\n",
+"clc;\n",
+"clear;\n",
+"close;\n",
+"//given data :\n",
+"Vm=230;// in volts\n",
+"Ia=10;// in A\n",
+"alpha=%pi/6;//degree\n",
+"ea=((2*Vm*sqrt(2))/%pi)*cos(alpha);//\n",
+"disp(ea,'average output voltage is,(V)=')\n",
+"isrms=Ia*(1-(2*alpha)/%pi)^(1/2);//\n",
+"disp(isrms,'rms value of supply current is,(A)=')\n",
+"I1rms=((2*sqrt(2)*Ia*cos(alpha))/%pi);//\n",
+"disp(I1rms,'rms value of fundamental component of supply current is,(A)=')\n",
+"hf=((isrms/I1rms)^2-1)^(1/2);//\n",
+"disp(hf*100,'HF of supply current is,(%)=')\n",
+"PF=((sqrt(2))*(1+cos(alpha)))/((%pi*(%pi-alpha))^(1/2));//\n",
+"disp(PF,'PF (lagging)of supply current is,(%)=')"
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}