List of figures – Motorola M68HC08 User Manual
Page 9
DRM028 — Rev 0
Designer Reference Manual
MOTOROLA
9
Designer Reference Manual — Sensorless BLDC Motor Control
List of Figures
Figure
Title
Page
System Concept . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
BLDC Motor Cross Section. . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
3-Phase Voltage System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
BLDC Motor Back EMF and Magnetic Flux . . . . . . . . . . . . . . . 26
Classical System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Power Stage — Motor Topology. . . . . . . . . . . . . . . . . . . . . . . . 28
Phase Voltage Waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Mutual Inductance Effect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Detail of Mutual Inductance Effect . . . . . . . . . . . . . . . . . . . . . . 33
Mutual Capacitance Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Balanced Capacity Coupling. . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Back-EMF Sensing Circuit Diagram . . . . . . . . . . . . . . . . . . . . . 37
The Zero Crossing Detection . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Commutation Control Stages . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Alignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
BLDC Commutation Time with Zero Crossing Sensing . . . . . . 43
Vectors of Magnetic Fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Back-EMF at Start Up. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
High-Voltage Hardware System Configuration . . . . . . . . . . . . . 59
Low-Voltage Hardware System Configuration . . . . . . . . . . . . . 63
MC68HC908MR32 Control Board . . . . . . . . . . . . . . . . . . . . . . 65
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Freescale Semiconductor, Inc.
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