Motorola M68HC08 - Manual (Page 35)

BLDC Motor Control
Brushless DC Motor Control Theory
DRM028 — Rev 0 Designer Reference Manual
MOTOROLA BLDC Motor Control 35
Figure 3-10. Distributed Back-EMF by Unbalanced
Capacity Coupling
Channel 1 in Figure 3-11 shows the disturbed “branch” voltage, while
the other phase (channel 2) is not affected because it faces balanced
mutual capacitance. The unbalance was purposely made by adding a
small capacitor on the motor terminals, in order to better demonstrate
the effect. After the unbalance was removed the “branch” voltage is
clean, without any spikes.
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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