REV.-A
PRINCIPLES OF OPERATION
Table 2-6. Current Values for Reference Voltages
With positive feedback through R9, a hysteresis, whose upper bound is the reference voltage, is generated
in the comparator of ICl. The comparator works as a Schmitt trigger, which senses a difference only when
the feedback (inverse terminal) is slightly larger or smaller than the hysteresis level. Reference voltage-a and
the feedback voltage are compared by the comparator in IC1. If reference voltage-a is HIGH, TR6 turns on,
applying approximately 25 VDC to the coil. The current rises linearly due to inductance, and TR6 turns off when
the feedback voltage reaches reference voltage. In this manner an almost constant current can be applied to
the coil.
Figure 2-39 shows the drive current waveform (pin 12) of the carriage motor and the chopping waveform (pin
17) of the drive voltage (+ 25 V), at 900 PPS. Figure 2-39 shows the Schmitt trigger circuit.
Figure 2-39. Chopping Waveforms
LQ-500/ L-1000
2-39
Summary of Contents for ActionPrinter L-1000
Page 1: ...LQ 500 L 1000 TECHNICAL MANUAL EPSON ...
Page 3: ...REV A REVISION SHEET iv LQ 500 L 1000 ...
Page 18: ...GENERAL DESCRIPTION REV A Figure 1 5 Character Matrix 1 10 LQ 500 L 1000 ...
Page 39: ...PRINCIPLES OF OPERATION REV A 2 2 LQ 500 L 1000 Figure 2 1 Cable Connections ...
Page 44: ......
Page 47: ...PRINCIPLES OF OPERATION REV A Table 2 2 Power Supply Applications 2 10 LQ 500 L 1000 ...
Page 77: ...PRINCIPLES OF OPERATION 2 40 REV A Figure 2 40 Schmitt Trigger Circuit LQ 500 L 1000 ...
Page 100: ...REV A PRINCIPLES OF OPERATION Table 2 20 Control Commands LQ 500 L 1000 2 63 ...
Page 106: ...REV A PRINCIPLES OF OPERATION Figure 2 64 Printing Routine LQ 500 L 1000 2 69 ...
Page 141: ...DISASSEMBLY ASSEMBLY AND ADJUSTMENT Table 4 5 VR2 Specifications REV A 4 26 LQ 500 L 1000 ...
Page 148: ...TROUBLESHOOTING REV A 1 Printer Does Not Operate with Power Switch ON 5 4 LQ 500 L 1000 ...
Page 149: ...REV A TROUBLESHOOTING 2 Abnormal Operation of Carriage LQ 500 L 1000 5 5 ...
Page 151: ...REV A TROUBLESHOOTING Figure 5 3 Printhead Resistance LQ 500 L 1000 5 7 ...
Page 152: ...TROUBLESHOOTING REV A 4 Abnormal Paper Feed with normal printing 5 8 LQ 500 L 1000 ...
Page 153: ...REV A TROUBLESHOOTING 5 Abnormal Operation of Control Panel LQ 500 L 1000 5 9 ...
Page 156: ...TROUBLESHOOTING REV A Table 5 6 Power Supply Circuit Unit Repair 5 12 LQ 500 L 1000 ...
Page 157: ...REV A T R O U B L E S H O O T I N G ...
Page 162: ...REV A MAINTENANCE Figure 6 2 LQ 500 L 1000 Lubrication Points LQ 500 L 1000 6 3 ...
Page 163: ......
Page 168: ......
Page 170: ...REV A APPENDIX Table A 5 µPD7810 7811 Port Functions LQ 500 L 1000 A 5 ...
Page 173: ...APPENDIX REV A Figure A 7 E01A05KA Block Diagram A 8 LQ 500 L 1000 ...
Page 174: ...REV A Table A 6 E01A05KA Pin Functions APPENDIX LQ 500 L 1000 A 9 ...
Page 185: ...APPENDIX REV A A 20 LQ 500 L 1000 ...
Page 186: ...REV A Table A 8 CN2 Connector Table A 9 CN3 Connector Cont A P P E N D I X LQ 500 L 1000 A 21 ...
Page 187: ...APPENDIX REV A Table A 10 CN4 Connector Cont Table A 12 CN6 Connector Cont A 22 LQ 500 L 1000 ...
Page 188: ...REV A APPENDIX Table A 17 Part No Reference Table LQ 500 L 1000 ...
Page 189: ...APPENDIX REV A Figure A 24 LQ 500 Exploded Diagram A 24 LQ 500 L 1000 ...
Page 190: ...REV A APPENDIX Figure A 25 M5410 Printer Mechanism Exploded Diagram LQ 500 L 1000 A 25 ...
Page 191: ...APPENDIX REV A Figure A 26 Tractor Unit A 26 LQ 500 L 1000 ...
Page 192: ......
