Carriage Motor Drive Circuit - Epson STYLUS 4001968 Service Manual

STYLUS

2.3.2.4 Carriage Motor Drive Circuit

Carriage motor drive IC SLA7024 (IC13) drives the carriage motor for the printer mechanism by a
I
constant current, unipolar drive system. Gate array E05A85EB (IC3) selects the motor phase drive
current level using the output signals from ports CRO to CR3 (pins 75 to 78). The phase switching
operation is directly controlled by the phase control signals output from ports P600 to P603 (pins 1
to 4) of the CPU. The table below shows the carnage m-otor drive modes.
speed
CR
225
150
83
40
HOLD
CPU
(ICI)
800 Service
Manual
Table 2-6. Carriage Motor Drive Modes
Drive
Frequency
5400
3600
2000
960
—
2
3
4
R59
7 5
Figure 2-17. Carriage Motor Drive Circuit Block Diagram
Acceleration
Phase
Current
Excitation
(A/Phase)
1-2 phase 0.80
1-2 phase 0.60
1-2 phase 0.80
1-2 phase 0.45
2 phase
SLA7024MEL
7
'
5
IN-A
RM25
Operating Principles
-
Normal/Deceleration
Current
(A/Phase)
0.45/0.80
0.30/0.60
0.80
0.30/0.45
Approx. 0.15
CR
Motor
8
A
1
-A
CR-A
18
B
11
—
CR-B
-B