Stepper Motors

1
Stepper Motors

• Cleverness with Magnets and Coils

2
Stepper Motors
Different types of stepper motors
Differences in Characteristics
Stepper Drive Techniques
Stepper Dynamics
Snubbing for Stepper Motors
3
The Permanent Magnet (PM) Stepper Motor
4
PM Stepper Operation
5
Torque v.s. Angular Displacement
6
The Variable Reluctance (VR) Stepper Motor
7
The Hybrid Stepper Motor
8
The Hybrid Motor Rotor
9
Offset Teeth in Hybrid Rotor
10
Variations in Output Torque
11
Stepper Motor Wiring
12
Winding Direction is Important
13
2-Phase Universal Wound v.s. 4-Phase
14
Driving Stepper Motors
15
Stepper Sequences Full Step
16
Driving Full Step
17
Stepper Sequences Wave Drive
18
Driving Wave Drive
19
Stepper Sequences Half-Step
20
Driving Half-Step
21
Stepper Sequences Micro-Stepping
22
Generating the Drive
Logic Sequencer
Coil Drive
23
Stepping Dynamics
24
Load Affects the Step Dynamics
25
Drive Affects the Step Dynamics
b
a
26
Stepper Motor Performance Curves
27
Current Dynamics
28
L/nR Drive
29
Current Rise in Detail
30
Performance Improvement with L/nR Drive
31
2-Level Drive
32
Chopper Drive
33
Diode Snubber for an H-Bridge
34
Zener Diode Snubber for and H-Bridge
35
Several other alternatives
36
Snubber Summary
37
Affects of Snubbing on Performance