Paper Feed And Carriage Motor Drive Circuit - Brother MP-21C Service Manual

2.3.3

Paper Feed and Carriage Motor Drive Circuit

A PM-type stepper motor is used to feed paper and is driven at a constant voltage. A DC
motor is used for the carriage. It uses the feedback signal (EINT-P) from the linear
encoder and its speed is controlled via the gate array by the CPU using the PWM control
method. The paper feed driving circuit is turned on and off by the M5VCNT signal from
the CPU.
#4
CPU
#4
CPU
#7
G/A
Fig. 2.6
#7
EINT-P
DCM0
G/A
DCM1
DCM0N
DCM1N
Fig. 2.7
II-6
12V
M5VCNT
#1
LF Driver
M54676
STPM0
STPM1
STPM0N
STPM1N
STPPWM0
STPPWM1
P6
ENC 2-P
ENC 1-P
#2
P4
#3 CR Drive motor
P1
To LF Motor
To
Encoder sensor on
the carriage PCB
To CR Motor