Epson Stylus Color 640 Service Manual page 76

EPSON Stylus Color 440/640/740
2.2.4.7 PF (Pump) Motor Drive Circuit
IC15(LB1845) on C206 Main-B, C255 Main board, IC15(UDN2917) on
C256 Main board, and IC12/13(A3956) on C257 Main board are used
for driving PF (Pump) motor. In the IC, Bi-pola drive PWM current
control type is performed, making it possible to provide stable current to
each phase of motor. Also, it makes possible to change over the
reference voltage as drive current settings by making few combinations
using current setting ports(input). However, firmware does not support
Micro-step in the Stylus Color 440/640/740. The figures below show
connection diagram of PF (Pump) motor drive circuit.
Chapter 2 Operating Principles
E05B44
(IC2)
59
PFAPH
58
PFA1
57
PFA0
50
PFBPH
56
PFB2
55
PFB0
46
PFV0
47
PFV1
48
PFV2
49
PFV3
+5
Figure 2-35. PF (Pump) Motor Drive Circuit for Stylus Color 440
E05B43
(IC2)
57
PFA0
58
PFA1
55
PFA0
56
PFB1
56
PFB2
59
PFAPH
46
PFV0
47
PFV1
48
PFV2
49
PFV3
+5
Figure 2-36. PF (Pump) Motor Drive Circuit for Stylus Color 640
Revision A
LB1B45
CN7
(IC15)
A
25 7
PH1
Out1A 1
23 6
I11
Out1B
/A
9
22
I01 Out2A
3
8
18
Rotor
PH2
Out2B
20
I12
B
21
2
I02
/B
4
26
Vref1
17
Vref2
UDN2917
CN7
(IC15)
A
2 6
I10 1
Out1A
1 3
I11
Out1B
/A
18
23
I20 Out2A 3
21
24
Rotor
I21 Out2B
43
PH1
B
26
2
PH2
/B
4
44
Vref1
25
Vref2
76