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+// chapter 8
+// example 8.27
+// Determine range of duty cycle, peak-to-peak choke ripple current and average supply current
+// page-523-524
+clear;
+clc;
+// given
+Edc=24; // in V (dc source)
+f=50; // in KHz (switching frequency)
+L=500; // in uH
+E0=15; // in V (average output voltage)
+Edc_max=26; // in V (maximum voltage of dc source)
+Edc_min=21; // in V (maximum voltage of dc source)
+I0=2; // in A (average load current)
+// calculate
+f=f*1E3; // changing unit from KHz to Hz
+L=L*1E-6; // changing unit from uH to H
+// since E0=Edc*alpha/(1-alpha), therefore we get
+alpha_max=1/((Edc_min/E0)+1); // calculation of upper limit of duty cycle
+alpha_min=1/((Edc_max/E0)+1); // calculation of lower limit of duty cycle
+alpha_normal=1/((Edc/E0)+1); // calculation of normal duty cycle
+del_I=Edc*alpha_normal/(f*L); // calculation of peak-to-peak choke ripple current
+// since Edc*Is=E0*I0, therefore we get
+Is=E0*I0/Edc; // calculation of average supply current
+printf("\nThe duty cycle varies from \t\t\t\t\t\t %.3f to %.3f",alpha_min,alpha_max);
+printf("\nThe peak-to-peak choke ripple current for normal supply voltage is \t del_I=%.1f mA",del_I*1E3);
+printf("\nThe average supply current drawn from battery is \t\t\t Is=%.2f A",Is);
+// Note: the answers vary slightly due to precise calculation
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