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Diffstat (limited to '2252/CH19/EX19.9/Ex19_9.sce')
| -rwxr-xr-x | 2252/CH19/EX19.9/Ex19_9.sce | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/2252/CH19/EX19.9/Ex19_9.sce b/2252/CH19/EX19.9/Ex19_9.sce new file mode 100755 index 000000000..266cd5a22 --- /dev/null +++ b/2252/CH19/EX19.9/Ex19_9.sce @@ -0,0 +1,19 @@ +
+N1=600//initial speed of the motor in rpm
+Ia1=20//armature current
+V=200//applied voltage
+Ra=.4//armature resistance
+Eb1=V-Ia1*Ra
+Rf1=200//field resistance
+If1=200/200//field current
+N2=900//increased speed in rpm
+//If2=200/Rf
+//phi1/phi2=If1/If2=Rf/200
+//Ia2=Ia1*phi1/phi2=.1*Rf
+//Eb2=200-.04*Rf
+//back emf is directly proportional to flux and speed
+//we get a quadratic equation in Rf as .04*Rf^2-200*Rf+57600=0
+//solving for Rf
+Rf2=(200-sqrt(200^2-4*.04*57600))/(2*.04)
+mprintf("Additional resistance in the shunt field circuit=%f ohm",Rf2-Rf1)
+
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