Epson LQ-2550 Technical Manual page 132

REV.-A
CR Motor Drive Circuit
Figure 2-81 shows the CR motor drive circuit. Figure 2-82 shows the CR motor drive circuit signal timing.
This circuit employs unipolar stepper motor driver IC S17304 (7 C), and drives the CR motor using
constant current chopper type control. The chopper type control is performed by a separately-excited
system. The +35 V power supply voltage is applied intermittently to the CR motor coil from
so that a mean voltage is applied to the CR motor coil, which keeps the CR motor current constant.
BC
COM
Refer to Appendix A.1.l.12 for details of the S17304.
6
BO1
3
C o l
7
AO1
R 9 3
GH
SURGE VOLTAGE
- - - 1
I
CR MOTOR
16 6 7 i
Y Y
DA1
I
1
12
4
3
I
t
GH
I
REFERENCE
VOLTAGE
GENERATION
CIRCUIT
Figure 2-81. CR Motor Drive Circuit
SURGE VOLTAGE
t
I
0
-----
- -
9 1 0 11 18
Y
- - - I
T
PHASE B PHASE D
DRIvER DRIvER
t t
r
I 1
,
2-86
SURGE VOLTAGE A8SORVlNG
CIRCUIT
I
0 1 5
+35
Z04
u ,
L - - - - - - - - - - - - - - -
(7C)
2
R66
+35
and
AC
COM
. . .