A3981 Allegro Micro Systems, Inc., A3981 Datasheet - Page 35

• Manufacturer Part Number: A3981
• Manufacturer: Allegro Micro Systems, Inc.

A3981
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Figure A1. Basic principle of bipolar stepper motor operation
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Rotor
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Rotor
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Stator
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Rotor
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Rotor
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Automotive, Programmable Stepper Driver
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(a)
• Phase A energized in positive direction
• Phase B not energized
Permanent magnet poles on the rotor aligned with
electromagnet poles on the stator
(b)
• Phase A not energized
• 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.
• 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.
• 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.
115 Northeast Cutoff
1.508.853.5000; www.allegromicro.com
Allegro MicroSystems, Inc.
Worcester, Massachusetts 01615-0036 U.S.A.
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