Epson LX-300 Service Manual

LX-300 Sarvica Manual
Operating
Pdnoipk
2.3.6 Carriage Motor Driver Circuit
Figure 2-17 shows the carriage motor driver arcuit. The carriage motor driver uses an open-loop,
constant-current drive arrangement. The motor is driven with 2-2 phase excitation and 1-2 phase
excitation.
The
~rriage motor driver IC (Al) detects the amount of current in the carriage motor coils and
regulates the current. The amount of current flowing in the coils varies, depending on the speed of
the carriage motor.
l’he amount of the current is set by the system IC (IC1). Signals are sent to
CRI1 and CR12 on the system IC. The motor driver IC sets the coil current to correspond to the
carriage motor speed. Ports
PAO - PA3 on the CPU block control the stepping motor via the gate
array block in IC1.
Table 2-9. Carriage Motor Drive Modes
t
1
Driver Mode
Excitation Type
3 x speed
2-2 phase
I
2 x speed
1-2 phase
I
I
1 x speed
I
1-2 phase
2/3 x speed 1-2 phase
I
7/8 x speed I
1-2 phase
Drive Frequency Type
Standard Print Character
I
1080 pps
I 80dpiprinting (draft) I
1800 pps
80
dpi printing
800 pps
180 dpi printing (LQ)
120,90 d~i mintirm
533pps
180,120,90 dpi printing
T
830 ppa
I Home position seek
I
+5V+5V
tt
CR MOTOR
SYSTEM IC(IC1)
R4{ {R5
DRIVE IC(A1)
1
1
1- TDB
BF1 OUT
~ ‘ 4 INB
BF20UT
‘%
BF1 IN
=
BF21N ‘a
+5V
PA3
*
PA2 ~
PA1 ‘la
PAO 141 ‘1 b ,sA-
CRII =
~sB
CR12 2
PGA
R8
A
t-
‘
1
1- GB
OA
o-P
OB
o-e
MOTOR
ASSY.,CR
=
1
CRA
10
CR-A
CRB
VP+
CR-B
Figure 2-17. Carriage Motor Driver Circuit Diagram
Rev.A
2-15

Epson LX-300 Specifications

General

Print Method	9-pin impact dot matrix
Interface	Parallel
Paper Handling	Friction feed, tractor feed
Weight	4.4 kg
Operating Environment	Temperature: 5 - 35°C, Humidity: 10 - 80%