1 files changed, 41 insertions, 0 deletions
diff --git a/1092/CH4/EX4.9/Example4_9.sce b/1092/CH4/EX4.9/Example4_9.sce
new file mode 100755
index 000000000..b506a0c03
--- /dev/null
+++ b/1092/CH4/EX4.9/Example4_9.sce
@@ -0,0 +1,41 @@
+// Electric Machinery and Transformers
+// Irving L kosow 
+// Prentice Hall of India
+// 2nd editiom
+
+// Chapter 4: DC Dynamo Torque Relations-DC Motors
+// Example 4-9
+
+clear; clc; close; // Clear the work space and console.
+
+// Given data
+I_l_orig = 40; // original Line current in A
+I_l_final = 66; // Final Line current in A
+
+phi_orig = 1; 
+// field flux is increased by 12% so EMF produced and terminal 
+// voltage will also increase by 12%
+phi_final = 1.12;
+
+V_a = 120;
+R_sh_orig = 60; // Original Field ckt resistance in ohm
+R_sh_final = 50 ; // Decreased final field ckt resistance in ohm
+
+R_a = 0.2; // Armature resistance in ohm
+BD = 3; // Brush voltage drop in volt
+S_orig = 1800; // Rated full-load speed
+
+// Calculations
+I_f_orig = V_a / R_sh_orig ; // Original Field current in A
+I_a_orig = I_l_orig - I_f_orig ; // Original Armature current @ full load
+E_c_orig = V_a - ( I_a_orig * R_a + BD ) ; // Back EMF @ full load
+
+I_f_final = V_a / R_sh_final ; // Final field current in A
+I_a_final = I_l_final - I_f_final ; // Final Armature current in A
+E_c_final = V_a - ( I_a_final * R_a + BD ) ; // Final EMF induced
+S = S_orig * ( E_c_final / E_c_orig ) * ( phi_orig / phi_final ) ; 
+// Final speed of the motor
+
+// Display the result
+disp("Example 4-9 Solution : ");
+printf(" \n S = %.1f rpm ", S );