//Book name: Fundamentals of electrical drives by Mohamad A. El- Sharkawi //chapter2 //example 2.2 clc; clear; sv=(2^(1/2))*120*sind(30);//rms value of voltage source K=0.2; // constant whose value dependent ondevice characteristics bv=200; //base voltage in volts ig=((log(sv/bv))/(-K)); //gate current in mA disp(ig,'gate current required to trigger the SCR at 30 degree in milliamphere is')