Motor Drive Circuits - Brother LX-300 Service Manual

5.5 Motor Drive Circuits

S
Paper Feed Motor Drive Circuit
This circuit conducts the paper feed motor bipolar drive using 2-2 phase excitation
from the +24 VDC stabilized constant voltage.
The stepping motor excitation phases A, A , B, and B are controlled by main CPU
ports P03, P02, P04, and P01 and the Paper feed motor is controlled by Driver #6.
The Paper feed motor current limit values can be switched using P00, P05, and P06.
S
SG Motor Drive Circuit
This circuit drives the SG motor using 2-2 phase excitation from the +24 VDC
stabilized constant voltage.
The stepping motor excitation phases A, B, C, and D are controlled by main CPU
ports P47, P46, P45, and P44 and the four transistors Q17 to QA20 drive the SG
motor.
Fig. 5.5-1 Paper Feed Motor Drive Circuit
Fig. 5.5-2 SG Motor Drive Circuit
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