//CHAPTER 8- DIRECT CURRENT MACHINES //Example 30 disp("CHAPTER 8"); disp("EXAMPLE 30"); //Series DC motor 5 HP with 100 rpm //VARIABLE INITIALIZATION p=5*735.5; //in Watts (1 metric H.P.=735.5 W) N=1000; //in rpm, given as 100 rpm but solved as 1000 rpm in the text book //hence taken 1000 rpm I=30; //in Amperes I_s=45; //starting current in Amperes //SOLUTION T=(p*60)/(2*%pi*1000); // Torque //Torque dir prop phi.Ia //=> since phi dir prop Ia //=> torque dir prop Ia^2 // starting torque T_s / T = Starting current Ia ^2 / I^2 T_s=(T*(I_s^2))/(I^2); disp(sprintf("The starting torque is %.0f N-m",T_s)); //The answer is slightly different due to precision of floating point numbers //END