A4979 Datasheet, PDF (36/44 Pages) Allegro MicroSystems – The A4979 is a flexible microstepping motor driver with built-in translator for easy operation.

A4979
Microstepping Programmable Stepper Motor Driver
With Stall Detect and Short Circuit Protection
Stator
__
__
ABABABAB
N
S
N
S
A
S
N
S
N
N
N
S
N
S
S
Rotor
Stator
__
__
ABABABAB
N
S
N
S
A
N
S
N
S
N
S
N
S
N
S
Rotor
Stator
__
__
ABABABAB
S
N
S
N
A
N
S
N
S
N
S
N
S
N
S
Rotor
Stator
__
__
ABABABAB
A
S
N
S
N
S
N
S
N
S
N
S
N
S
N
Rotor
Figure A1. Basic principle of bipolar stepper motor operation
(a)
• Phase A energized in positive direction
B
• Phase B not energized
Permanent magnet poles on the rotor aligned with
electromagnet poles on the stator
(b)
• Phase A not energized
B
• Phase B energized in positive direction
Rotor moves to the right to realign permanent
magnet poles on the rotor to the electromagnet
poles on the stator.
(c)
• Phase A energized in negative direction.
B
• Phase B not energized
Rotor moves to the right to realign permanent
magnet poles on the rotor to the electromagnet
poles on the stator.
(d)
• Phase A not energized.
B
• Phase B energized in negative direction
Rotor moves to the right to realign permanent
magnet poles on the rotor to the electromagnet
poles on the stator.
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
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