Thermal Mechanism Drive Circuit - Epson TM-H6000 Service Manual

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Thermal Mechanism Drive Circuit

Paper Feed Motor Drive Circuit
The paper feed motor drive circuit drives the thermal receipt feed motor, a 2-phase stepping
motor. The motor is driven with 2-2 phase excitation at a constant current (partial 1-2 phase
excitation). Therefore, a dedicated driver IC is used for the drive.
WIRE LAND
24VA A1
A2
VCC-PWR2
J5
J1
THPF_I02
THPF_I12
THPF_PH2
C70
THPF_DA
THPF_PH1
THPF_I11
THPF_I01
When the 24VSW2 GA output terminal goes HIGH, 24VA and VCC-PWR2 are supplied,
enabling the driver IC for the paper feed motor to operate. The current can be set at the logic
level described in the table below in this status. Firmware-based DA output of the CPU is used
to set the current (VREF1, 2 terminal voltage).
The VREF is set by firmware (range: 0 - VCC) to control the current. Constant current operation
is controlled at that current setting. The logic level of PH1, 2 phase data is changed to drive the
circuit.
TableD-12 Output current
I0
L
H
L
H
Rev. A
U18
I O
C65
C64
C63
U19
1
THPF_I02
I02
2
THPF_I12
I12
THPF_PH2 3
PHASE2
4
VREF2
5
RC2
C71 6
G
7
G
8
VCC
9
RC1
10
THPF_DA
VREF1
11
THPF_PH1
PHASE1
12
THPF_I11
I11
THPF_I01
R136
R137
C74
C75
I1 Output Current
VREF / (10 × Rs)
L
VREF / (15 × Rs)
L
VREF / (25 × Rs)
H
H 0
24
VBB
23
OUT2B
22
SENSE2
21
E2
20
OUT2A
19
G
18
G
17
OUT1A
16
E1
15
SENSE1
14
OUT1B
13
I01
R138
C77
Figure D-62
TM-H6000/H6000P Service Manual
D33
D34
D35
D37
PH_A+
PH_A-
PH_B+
PH_B-
R139
R141 R142
C78
Product Overview Appendix D-63
M