// Electric Machinery and Transformers // Irving L kosow // Prentice Hall of India // 2nd editiom // Chapter 4: DC Dynamo Torque Relations-DC Motors // Example 4-4 clear; clc; close; // Clear the work space and console. // Given data slots = 120 ; // No. of armature slots conductors_per_slot = 6 ; B = 60000 ; // Flux density in lines/sq.inches d = 28 ; // diameter of the armature l = 14 ; // axial length of the coil in inches A = 4 ; // No. of parallel paths span = 0.72 ; // Pole arcs span 72% of the armature surface I = 133.5 ; // Armature current in A // Calculations Z_Ta = slots * conductors_per_slot * span ; // No. of armature conductors F_t = ( B * I * l )/ ( 1.13 * 10 ^ 7 * A ) * Z_Ta ; // Force developed in lb r = ( d / 2 ) / 12 ; // radius of the armature in feet T = F_t * r ; // Tital torque developed // Display the result disp("Example 4-4 Solution : ") printf(" \n T = %d lb-ft", T );