Operating Principles LX-1050+ Service Manual
2.3.2.4 Paper Feed Motor Drive Circuit
The
paper-feed motor drive circuit is shown in
following
figure.
me
paper-feed motor is a step
motor which can utilize 2-2 phase excitation. When the paper-feed signal
PC2
is set to HIGH, Q20
and Q16 are turned on, and +24 V is supplied to the motor. When the paper-feed motor is not
driven, +5 V is supplied, via resistor
R42
and diode D6, to hold the motor.
The paper feed motor is a 48-pole step motor and is
open-loop
controlled. When 2-2 phase
excitation is used to drive the motor, each step feeds the paper a distance of l/216th inch.
CPU
rffPD78 10HG(2C)
I
PC2
EO:\O(3 B)PFA
PFB
PFC
PFD
+24V
+5V
R36
AA
3.3K
,
I?44
5.6K
R45
19
5.6K
RI 16
33K
12
8
11
8
R87 3.3K
7
VAVAV
9
R89 3.3K
VAVAV
10
R86 3.3K
v
VAV
11
R88 3.3K
Vhvf
PFCOM
PFCOM
PF A
PF B
PF C
PF D
GP
Figure 2-16. Paper Feed Motor Drive Circuit