Slip Paper Feed Motor Drive Circuit - Epson TM-U675 Service Manual

Confidential
The drive signal to drive the phases is sent at the logical level of the PHASE1, 2 terminals. The
motor driver cannot operate unless signal 24VSW1 in the circuit diagram is set to HIGH
(controlled by the GA). When this signal is at a status other than HIGH, IC consumption is 0,
and no electricity goes to the motor.

Slip Paper Feed Motor Drive Circuit

The slip paper feed motor is two-phase stepping motor. The driving method is 1-2 phase
excitation during acceleration and deceleration, and constant-current drive is performed with
2-2 phase excitation. Therefore, a dedicated constant-current drive chopping driver (U17,
A2917SEB made by Alegrow) is used.
Q30
3 2
PF_HOLD 2
1
DTC114EK
5
6
The circuit configuration is the same as the carriage motor driver, but the current setting is fixed,
and is changed between two levels by the output (PF_HOLD) of the GA (U30) port. The current
calculation procedure is described below.
Current = VREF/(10
Ω
RS: 1
VREF: VCC or voltage obtained by voltage division ratio of R105 and R106.
As for the carriage motor drive circuit, the driver IC is operated by setting the 24VSW1 signal
HIGH.
Appendix D-58 Product Overview
VCC 24VC
R105
68K
1%
3
+
2
R106
-
1 U16A
NJM2904M
30K
1% C53
0.1uF
Q18
+
7
2
24VSW1
-
U16B
NJM2904M
DTC114EK
Rs)
R103
75K
PF_I21
PF_PH2
1
29
G
30
G
31
G
32
G
3 33
G
34
SLIP-PF
G
35
G
36
G
1 37
G
38
G
39
G
R113
3.3K
VCC-PWR
PF_PH1
PF_I11
C56
0.1uF R118
75K
C54
6.3V
47uF
Figure D-54
24VC
C49 R102
3300pF 1
1W
C50 1%
R104
470pF 1 2
1K
U17
A2917SEB
17
G
16
G
15
G
14
G
13
G
12
G
11
G
10
G
9
G
8
G
7
G
R117
1 2
C55 1K
470pF C57
3300pF
R119
1
1W
1%
PF_A+
PF_A-
M
PF_B-
PF_B+
D26
EC10QS06
D27
EC10QS06
D29
EC10QS06
D30
EC10QS06
Rev.D