Problems
1-
Solution
(a)
 A
B
C D
nm  720 rpm
(b)
0
1
0
0
0
45
1
1
0
0
90
0
1
0
0
135
0
1
1
0
720
 12 rev / sec
60
Number of signals(ni bbles)/rev  8 nibbles/re v
180
0
0
1
0
Number of nibbles/re v  12  8  96 nibbles/se c
225
0
0
1
1
270
0
0
0
1
315
1
0
0
1
nm 
1
2- Sketch a cross-sectional view of a single-stack variable reluctance stepper motor
with 4 phases, 8 stator poles and 6 rotor poles. Determine its step angle.
Solution
(a)
(b)
m  4, N s  8, N r  6
360
 45
8
360
r 
 60
6
   s   r  15
s 
or

8/6, four-phase SRM
r
m

60
 15
4
2
3)
Determine the step size and the step rate (no of steps/rev)
for Five stake, four pole, 3 teeth/pole, variable reluctance
stepper motor i-..
Solution
S  5, N  4, x  3
360
360


 6
S .N .x 5  4  3
360
No of steps / rev. 
 60 steps / rev

3