Motor Drive Circuits - Brother LX-200 Service Manual

5.5 Motor Drive Circuits

Paper Feed Motor Drive Circuit (LF Motor)
This circuit drives the paper feed motor using 2-2 phase excitation from the +24V DC
stabilized constant voltage.
The stepping motor excitation phases A, B, C, and D are controlled by main CPU
ports P72, P73, P70, and P71, respectively. The four transistor arrays incorporated
into QA2 drive the paper feed motor.
Trimming Motor Drive Circuit
This circuit drives the trimming motor using 2-2 phase excitation from the +24V DC
stabilized constant voltage.
The stepping motor excitation phases A, B, C, and D are controlled by main CPU
ports P76, P77, P74, and P75, respectively. The four transistor arrays incorporated
into QA1 drive the trimming motor.
Fig. 5.5-1 Paper Feed Motor Drive Circuit
Fig. 5.5-2 Trimming Motor Drive Circuit
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