1 files changed, 37 insertions, 0 deletions
diff --git a/3731/CH5/EX5.8/Ex5_8.sce b/3731/CH5/EX5.8/Ex5_8.sce
new file mode 100644
index 000000000..02f4e22e9
--- /dev/null
+++ b/3731/CH5/EX5.8/Ex5_8.sce
@@ -0,0 +1,37 @@
+//Chapter 5:Dc Motor Drives
+//Example 8
+clc;
+
+//Variable Initialization
+
+//Ratings of the separately excited motor
+V=220     // rated voltage in V
+N=970     // rated speed in rpm
+Ia=100    // rated current in A
+Ra=0.05   // armature resistance in ohms
+N1=1000   // initial speed of the motor in rpm
+
+//Solution
+E=V-Ia*Ra
+E1=N1/N*E   //value of back emf at the speed N1
+
+//(a)The resistance to be placed
+Ia1=2*Ia         //value of the braking current is twice the rated current
+Rb=(E1+V)/Ia1-Ra  //required resistance
+
+//(b)The braking torque
+Wm=(2*%pi*N1)/60
+T=E1*Ia1/Wm
+
+//(c)When the speed has fallen to zero the back emf is zero
+E2=0
+Ia2=V/(Ra+Rb)
+T2=Ia2/Ia1*T   //since the torque is directly proportional to the current
+
+
+//Results 
+mprintf("(a)Hence required resistance is :%.2f ohm",Rb)
+//Answer given for the resistance in the book is wrong
+
+mprintf("\n(b)Hence the required braking torque is :%.1f N-m",T)
+mprintf("\n(c)Hence the required torque is :%.1f N-m",T2)