OPERATING PRINCIPLES
Rev. B
2-33
2.3.9 Printhead Drive Circuit
Figure 2-27 shows a printhead drive circuit block diagram.
General :
The print data lines from IC1 are active when they are HIGH. When ports HDR1 (HDL1) to HDR9 (HDL9)
of IC1 go HIGH, the FET gates are biased, and the FETs are turned on to apply the current to the
printhead coil. At the same time, ports HDRS1 (HDLS1) to HDRS9 (HDLS9) of IC1 go HIGH, the FET
gates are biased, and the FETs are turned on because the each printhead coil is driven by bipolar drive
method. When the HD port of IC1 goes LOW, the FET is turned off and the printhead coil current is cut.
Two +37 VDC lines (VP1-GP1 on the C204 DRV-B board and VP2-GP2 on the C204 MAIN board) assign
the common voltage for the printhead coil. Pins #1, #2, #7, #9, #10, #11, #12, #16, and #17 are supplied
by the VP2-GP2 line (CN1 on the C204 MAIN board). Pins #3, #4, #5, #6 #8, #13, #14, #15, and #18 are
supplied by the VP1-GP1 line (CN1 on the C204 DRV-B board).
The CPU monitors the printhead temperature and head fan (HF) temperature. When the temperature
rises abnormally, printing stops at once until the temperature cools.
The CPU also monitors the printhead driver status, P-channel and N-channel FET respectively. If the
printhead driver FET shorts, CPU (IC2) port PDRERR (P-channel) / NDRERR (N-channel) detects HIGH
level and the E05B36 (IC1) sends the DRERR (Driver Error) signal to the C204 PSB/PSE board. When
the C204 PSB/PSE board receives this signal, it stops the output voltage and the printer beeps.
E05B36 (IC1)
FANA
Q
10
Q
11
HFANA
HFANB
FANAX
H
D
R
S
1-H
D
R
S
9
H
D
R
1-H
D
R
9
H
D
LS
1-H
D
LS
9
H
D
L1
-H
D
L9
Printhead Driver Circuit
1/2
Printhead Coils 1/2
DRV-B Board
Printhead Driver
Circuit 2/2
Printhead Coils 2/2
MAIN Board
VX VP1 GP1
VX VP2 GP2
GP2
VP2
R100
R101
N
D
R
E
R
R
GP2
R98
R99
ZD4
ZD1
P
D
R
E
R
R
TMP95C061A
(IC2)
Monitoring PNPs
Short Circuit
Monitoring NPNs
Short Circuit
24V
5.1V
Printhead Thermistor
H
N
S
E
N
S
HPSENS
HTMP
HF Motor Thermistor
FTMP
H
TM
P
FT
M
P
HF Motor
Figure 2-27. Printhead Drive Circuit Block Diagram
Содержание DFX-8500 - Impact Printer
Страница 1: ...EPSON IMPACT SERIAL DOT MATRIX PRINTER DFX 8500 SERVICE MANUAL SEIKO EPSON CORPORATION 4009310 ...
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Страница 173: ...CHAPTER 5 TROUBLESHOOTING 5 1 PROBLEM ISOLATION 5 1 5 2 SELF DIAGNOSTIC FUNCTION 5 2 5 3 TROUBLESHOOTING 5 3 ...
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Страница 201: ...CHAPTER 6 MAINTENENCE 6 1 PREVENTIVE MAINTENENCE 6 1 6 2 LUBRICATION AND ADHESIVE APPLICATION 6 1 ...
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Страница 205: ...MAINTENANCE Rev B 6 3 Figure 6 2 Lubrication and Adhesive Diagram 1 ...
Страница 206: ...DFX 8500 Rev B 6 4 Figure 6 3 Lubrication and Adhesive Diagram 2 ...
Страница 207: ...MAINTENANCE Rev B 6 5 Figure 6 4 Lubrication and Adhesive Diagram 3 ...
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Страница 225: ...APPENDIX Rev B A 21 A 3 Component Layout Figure A 7 C204 MAIN Board Component Layout 1 ...
Страница 226: ...DFX 8500 Rev B A 22 Figure A 8 C204 MAIN Board Component Layout 2 ...
Страница 227: ...APPENDIX Rev B A 23 Figure A 9 C204 DRV Board Component Layout 1 Figure A 10 C204 DRV Board Component Layout 2 ...
Страница 228: ...DFX 8500 Rev B A 24 Figure A 11 C204 DRV B Board Component Layout 1 Figure A 12 C204 DRV B Board Component Layout 2 ...
Страница 229: ...APPENDIX Rev B A 25 Figure A 13 C204 PSB Board Component Layout ...
Страница 230: ...DFX 8500 Rev B A 26 Figure A 14 C204 PSE Board Component Layout ...
Страница 236: ...DFX 8500 Rev B A 32 Figure A 16 Exploded Diagrams 1 ...
Страница 237: ...APPENDIX Rev B A 33 Figure A 17 Exploded Diagrams 2 ...
Страница 238: ...DFX 8500 Rev B A 34 Figure A 18 Exploded Diagrams 3 ...
Страница 239: ...APPENDIX Rev B A 35 Figure A 19 Exploded Diagrams 4 ...
Страница 240: ...DFX 8500 Rev B A 36 Figure A 20 Exploded Diagrams 5 ...
Страница 241: ...APPENDIX Rev B A 37 Figure A 21 Exploded Diagrams 6 ...
Страница 242: ...DFX 8500 Rev B A 38 Figure A 22 Exploded Diagrams 7 ...
Страница 243: ...APPENDIX Rev B A 39 Figure A 23 Packing Material ...
Страница 245: ...EPSON SEIKO EPSON CORPORATION ...