clear; clc; //Caption:SCR Relaxation Oscillator Phase control Circuit //Given Data C=0.1;//in microF V=60;//in V Vb=32;//in V Vh=10;//holding voltage in V Ih=100;//in microA c=45;//conductance angle in degree cd = 360 - c;//angle in which capacitor will get charged td = (cd/360)*(1/60);//in ms //if the anode voltage is positive,the SCR will fire when vc=32V vc=32;//in V //let time constant = t = R*C //vc-Vh = (V-Vh)(1-exp(-td/t)) t = -td/log(1-((vc-Vh)/(V-Vh))); disp('sec',t,'time constant = '); R = t/C;//Resistance in K disp('K',R*1000,'R='); //end