Motorola M68HC08 manual List of Figures, Title

Freescale Semiconductor, Inc.

Freescale Semiconductor, Inc.

Designer Reference Manual — Sensorless BLDC Motor Control

List of Figures

Figure Title Page

2-1 System Concept . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 3-1 BLDC Motor Cross Section. . . . . . . . . . . . . . . . . . . . . . . . . . . .24 3-23-Phase Voltage System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 3-3 BLDC Motor Back EMF and Magnetic Flux . . . . . . . . . . . . . . . 26 3-4 Classical System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 3-5 Power Stage — Motor Topology. . . . . . . . . . . . . . . . . . . . . . . . 28 3-6 Phase Voltage Waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 3-7 Mutual Inductance Effect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 3-8 Detail of Mutual Inductance Effect . . . . . . . . . . . . . . . . . . . . . . 33 3-9 Mutual Capacitance Model . . . . . . . . . . . . . . . . . . . . . . . . . . . .34 3-10 Distributed Back-EMF by Unbalanced

Capacity Coupling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35 3-11 Balanced Capacity Coupling. . . . . . . . . . . . . . . . . . . . . . . . . . . 36 3-12Back-EMF Sensing Circuit Diagram . . . . . . . . . . . . . . . . . . . . .37 3-13 The Zero Crossing Detection . . . . . . . . . . . . . . . . . . . . . . . . . . 38 3-14 Commutation Control Stages . . . . . . . . . . . . . . . . . . . . . . . . . . 39 3-15 Alignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 3-16 BLDC Commutation with Back-EMF

Zero Crossing Sensing Flowchart. . . . . . . . . . . . . . . . . . . . . . . 42 3-17 BLDC Commutation Time with Zero Crossing Sensing . . . . . . 43 3-18 Vectors of Magnetic Fields . . . . . . . . . . . . . . . . . . . . . . . . . . . .47 3-19Back-EMF at Start Up. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 3-20 Calculation of the Commutation Times During the Starting

(Back-EMF Acquisition) State. . . . . . . . . . . . . . . . . . . . . . . . . . 49 4-1High-Voltage Hardware System Configuration . . . . . . . . . . . . . 59 4-2Low-Voltage Evaluation Motor Hardware

System Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 4-3Low-Voltage Hardware System Configuration . . . . . . . . . . . . . 63 4-4 MC68HC908MR32 Control Board . . . . . . . . . . . . . . . . . . . . . . 65

DRM028 — Rev 0	Designer Reference Manual
MOTOROLA	9

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