1 files changed, 24 insertions, 0 deletions
diff --git a/3760/CH4/EX4.87/Ex4_87.sce b/3760/CH4/EX4.87/Ex4_87.sce
new file mode 100644
index 000000000..ba9953d61
--- /dev/null
+++ b/3760/CH4/EX4.87/Ex4_87.sce
@@ -0,0 +1,24 @@
+clc;
+v=48; // supply voltage
+n=2400; // speed of permanent magnet DC motor
+i=0.8; // current drawn by motor
+ra=1; // armature resistance of motor
+disp('case a');
+Ea=v-i*ra; // generated EMF
+l=Ea*i;
+printf('No load rotational losses is %f W\n',l);
+disp('case b');
+km=(Ea*60)/(2*%pi*n); // speed voltage constant
+v=40; // supply voltage
+n1=1600; // speed at supply voltage
+Ea=(km*2*%pi*n1)/60; // generated EMF
+ia=(v-Ea)/ra; // new armature current
+pe=Ea*ia; // Electromagnetic power developed 
+po=pe-l;
+printf('Output power is %f W\n',po);
+disp('case c');
+v=20; // supply voltage
+// when motor stalls Ea=0 
+ia=v/ra; // stall current
+T=km*ia;
+printf('Stall torque is %f Nm',T);