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+// chapter 9
+// example 9.18
+// Desig a series invertor circuit
+// page-606
+clear;
+clc;
+// given
+f0=1, fr=5; // in KHz (range of frequency of operation)
+Rmin=25, Rmax=100; // in ohm (range of load resistance)
+Ip=3;  // in A
+Edc=100; // in V (dc source)
+AF=0.5; // attenuation factor (assumption as done in the book)
+// calculate
+f0=f0*1E3; // changing unit from KHz to Hz
+fr=fr*1E3; // changing unit from KHz to Hz
+wr=2*%pi*fr; // calculation of upper limit of angular velocity 
+w0=2*%pi*f0; // calculation of lower limit of angular velocity
+L=-Rmax/(8*fr*log(AF)); // calculation of inductance
+C=(1/L)*(1/(wr^2+(Rmax/(2*L))^2)); // calculation of capacitance
+Ec=Edc*(exp(-Rmin*%pi/(2*wr*L))/(1-exp(-Rmin*%pi/(2*wr*L)))); // calculation of capacitor voltage
+I_peak=(Ec+Edc)/(wr*L)*exp(-Rmin*%pi/(4*wr*L)); // calculation of peak current
+// since V_BO>=Ec+Edc, therefore 
+V_BO=Ec+Edc; // calculation of forward blocking voltage rating
+// since I_T>=I-peak, therefore 
+I_T=(I_peak+1); // calculation of Thyristor current
+Toff=%pi*((1/w0)-(1/wr)); // calculation of Thyristor off-time
+// since I_T>=I-peak, therefore 
+tq=Toff*1E3-0.1; // calculation of invertor trun off-time
+printf("\nThe inductance \t\t\t L=%.1f mH",L*1E3);
+printf("\nThe capacitance \t\t C=%.2f uF",C*1E6);
+printf("\nThe capacitor voltage \t\t Ec=%.2f V",Ec);
+printf("\nThe peak current \t\t I_peak=%.2f A",I_peak);
+printf("\nThe forward blocking voltage \t V_BO>=%.f V",V_BO);
+printf("\nThe Thyristor current \t\t I_T=%.f A",I_T);
+printf("\nThe Thyristor turn-off time \t Toff=%.1f ms",Toff*1E3);
+printf("\nThe invertor turn-off time \t tq=%.1f ms",tq);
+// Note: The answer varies slightly due to precise calculations and round off as done in the book
+\ No newline at end of file