Epson LX-300 Service Manual

Operating Principles
LX#Xl Service Manual
2.3.10 EEPROM Control Circuit
Figure 2-22 shows the EEPROM control arcuit block diagram. ‘The EEPROM (A5) contains such
information as the top-of-form position.
The EEPROM is non-volatile memory, so information is
not lost if the printer is powered off.
Since the EEPROM is a serial I/O-type device, the CPU
converts 8-bit data into serial data.
+5V
4
SYSTEM IC (ICI)
PB7
PB5
PBO
PB1
-+-h
ICT1
9
1
7
2
2
3
3
4
EEPROM (A5)
Cs
CK
DI
Do
J
Figure 2-22. EEPROM Control Circuit Diagram
2.3.11 CS Motor Assembly Circuit
Figure 2-23 shows a block diagram of the CS motor assembly arcuit in the optioml color upgrade
kit. The CS motor assembly is a pe
rmanent ma~et (PM) stepping motor, driven with 2-2 phase
excitation in proportion to the desired mtatioti speed. W motor GUI be rotated in either
direction and stopped at any position. Four phase signals are directly output from the system IC
and pass through a transistor array. The drive voltage is constant (i.e., +35 VDC from the VP line).
Source Voltage
35 VDc * 10 Yo
Current Con~ump60n
245 mA ( peak)
SYSTEM IC (ICI)
PA7
PA6
PA5
PA4
PB6
MOTOR ASSY.,CS
F
a
R20
Q1
14s
CS-B
147
R21 I
CS_A
14a
R22 I
CS B
14s
R23 I
(XA
+5V
*I
t
I
Printer
N
I +35V
“-%
(:
,...m
f,,;.
Color Upgrade Kit
Figure 2-23. CS Motor Assembly Circuit Diagram
2-18
Rev.A

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%