Stepper Motor Basics and Types with different modes of operation 1. Basics of stepper motor 2. step angle 3. types 4. Variable reluctance stepper motor 5. 1-phase-on mode 6. 2-phase-on mode 7. half step mode 8. PM stepper motor 9. Hybrid Stepper Motor 10. Application

1. STEPPER MOTOR

2. Stepper Motor Basics

3. Step Angle
 Angle through which motor shaft rotates for each command
pulse.
 Smaller the step angle, greater the no. of steps per resolution
 It can be varied from 0.72 to 90 degree.
Find step angle if stator has 3 phase and rotor has 4 teeth.
𝛽 =
𝑁𝑆 − 𝑁𝑟
𝑁𝑆 𝑁𝑟
∗ 3600
𝛽 =
3600
𝑚𝑁𝑟

5. Types
Stepper
Motor
Variable
Reluctance
Permanent
Magnet
Hybrid

6. Variable Reluctance Stepper Motor
 Multi Phase Stator.
 Salient Pole Rotor.
 Rotor made up of Ferromagnetic Materials
 Principle- A ferromagnetic material when placed in a
magnetic field always follows a low reluctance path.
 Reluctance between rotor and stator teeth is varied
with angular position of rotor.
 Direction of rotation depends upon Stator Current
Polarity.
 Methods of Operation
1. 1-phase-ON
2. 2-phase-ON
3. Half Step

7. 1-phase-ON or Full-Step Operation

9. 2-phase-ON

11. Truth Table for 2-phase-ON Mode
A B C Θ(degree
)
+ + 0 15
0 + + 45
+ 0 + 75
+ + 0 102
Sequence is AB, BC, CA, AB for a three phase stator.

12. Half-Step-Operation

14. Truth Table for Half Step Operation Mode
Sequence is A, AB, B, BC, C, CA, A for a three phase stator.
A B C Θ(degree) Supplie
d
Phase
+ 0 0 0 A
+ + 0 15 AB
0 + 0 30 B
0 + + 45 BC
0 0 + 60 C
+ 0 + 75 CA
+ 0 0 90 A

15. Permanent Magnet Stepper Motor
Multiphase Stator
Permanent Magnet in Rotor
Stator has projected poles but rotor is
Cylindrical
Principle- PM Rotor align itself with the
energised stator phase.
Two stator poles are energised by one
winding.
Methods of Operation
1. 1-phase-ON
2. 2-phase-ON
3. Half Step

17. Truth Table for Permanent Magnet Stepper
Motor
A B Θ (theta)
+ 0 0
0 + 90
- 0 180
0 - 270
+ 0 0
A B Θ (theta)
+ + 45
- + 135
- - 225
+ - 315
+ + 45
A B Θ (theta)
+ 0 0
+ + 45
0 + 90
- + 135
- 0 180
- - 225
0 - 270
+ - 315
+ 0 0
1-phase-ON Mode 2-phase-ON Mode
Half-Stepping Mode

18. Hybrid Stepper Motor
 Combination of VR and PM stepper motor.
 Rotor is made up of PM with variable
reluctance to create a pair of poles marked
N & S.
 Methods of Operation
1. 1-phase-ON
2. 2-phase-ON
3. Half Step