Motorola M68HC08 Reference Manual page 39

3.3.1.1 Alignment
DRM028 — Rev 0
MOTOROLA
Freescale Semiconductor, Inc.
position is known, and can be used to calculate the speed and
processing of the commutation in the running state.
Figure 3-14. Commutation Control Stages
fore the motor starts, there is a short time (depending on the motor's
Be
electrical time constant) when the rotor position is stabilized by applying
PWM signals to only two motor phases (no commutation). The current
controller keeps current within predefined limits. This state is necessary
in order to create a high start-up torque. When the preset time-out
expires then this state is finished.
BLDC Motor Control
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START MOTOR
ALIGNMENT
NO
ALIGNMENT TIME
EXPIRED?
YES
STARTING
(BACK-EMF ACQUISITION)
MINIMAL CORRECT
COMMUTATIONS DONE?
YES
RUNNING
BLDC Motor Control
Used Control Technique
NO
Designer Reference Manual
39