Epson LQ-300 - Impact Printer, Service Manual

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Operating Principles Service Manual
2.3.11 Control Circuit
Figure 2-23 shows the control circuit block diagram. The contains such
information as the top-of-form position. The is non-volatile memory, so information is
not lost if the printer is powered off. Since the is a serial I/O-type device, the CPU
converts 8-bit data into serial data.
CPU (lCl)
+5
v
A
05 Cs
Vcc
06
07
3
4
’
DO
GND
Figure 2-23. Control Circuit Diagram
2.3.12 CS Motor Circuit
Figure 2-24 shows a block diagram of the motor circuit in the optional color upgrade kit. The
CS motor is a permanent magnet (PM) stepping motor, driven with 2-2 phase in
proportion to the desired rotational speed. This motor can be rotated in either direction and
stopped at any position. Four phase signals are directly output from the system
and pass
through a The drive voltage is constant (i.e., +35 from the VP line).
Source Voltage 35 10
Current Consumption 245 ( peak)
I
GATE ARRAY
MOTOR
1
Q1
49
4a
47
04
B
CS A
Printer
Figure 2-24. CS
Color Upgrade Kit
Motor Circuit
2-18