2.3.4 CR Motor Driver Circuit
The CR motor driver circuit is shown below.
The carriage motor driver circuit controls the CR motor, using an open-loop, constant drive arrangement. 2-2
and 1-2 phases excite the motor. A 2-2 phase step is equivalent to a 1-2 phase step doubled. Ports 1 to 4 of
the SLA7024M are used to change the excitation phase, depending on the selected print mode. Table 2-8
describes the motor driver modes.
Table 2-8 CR Motor Driver Modes
Speed Mode
Print Speed
(CPS)
Drive
Frequency
(PPS)
Excitation
Phase
Applications
36/11
300
7200
1-2
Super Draft
3
275
6600
1-2
Draft
8/3
244
5866
1-2
Super Draft and Copy
2
183
4400
1-2
Super Draft and Power Down
3/2
138
3300
1-2
Draft and Power Down
1
92
4400
W1-2
LQ
1-2
Draft and Copy and Power Down
2/3
61
1464
1-2
LQ and Copy
1/2
46
2200
W1-2
LQ and Power Down
1/3
31
1464
W1-2
LQ and Copy and Power Down
1/4
23
1100
W1-2
Raster Graphics
The SLA7024M (IC12) CR motor driver circuit detects and regulates the amount of current flowing in the
carriage motor coil. The current flowing through the coil varies, depending on the speed of the CR motor.
The CPU sets the amount of current and signals are sent via ports 32 to port 35. The SLA7024M sets the coil
current, depending on the CR speed.
CPU
CR A
CR-A
CR B
CR-B
Gate
Array
IN A
IN B
IN-B
6
5
17
16
IN-A
1
2
3
4
PG00
PG01
PG02
PG03
R73
R74
R75
R76
+5V
R72
C31
R68
R67
C29, 30
R71
R69, 70
RFA
RFB
RSA
RSB
GND A
GNB B
A
-A
B
-B
3
14
9
10
4
15
CRI0
CRI1
CRI2
CRI3
62
63
64
65
+35V
CRCOM
S L A7 0 2 4 M
Address
Data Line
Figure 2-35 CR Driver Circuit
LQ-2070 Service Manual
Operating Principles
Rev.A
2-25
Summary of Contents for 2070 - LQ B/W Dot-matrix Printer
Page 1: ...EPSON TERMINAL PRINTER LQ 2070 SERVICE MANUAL EPSON 4006244 ...
Page 5: ...REVISION SHEET Revision Issued Date Revision Page Rev A April 8 1996 1st issued ...
Page 11: ...Product Description LQ 2070 Service Manual Figure 1 1 Exterior View of the LQ 2070 1 2 Rev A ...
Page 55: ...LQ 2070 Service Manual Operating Principles Rev A 2 7 ...
Page 58: ...Operation Principles LQ 2070 Servcie Manual 2 10 Rev A ...
Page 63: ...Down LQ 2070 Service Manual Operating Principles Rev A 2 15 ...
Page 112: ...Disassembly and Assembly LQ 2070 Service Manual 3 34 Rev A ...
Page 146: ...Maintenance LQ 2070 Service Manual 6 4 Rev A ...
Page 165: ...EPSON ...