Electrical Circuit Operating Principles; C298Psb/Pse Board; Electrical Circuit - Epson Stylus PHOTO 1270 Service Manual

EPSON Stylus Photo 870/1270

2.2 Electrical Circuit Operating Principles

The electric circuit of the Stylus Photo 870/1270 consists of the following:
"
Control circuit board: C304MAIN
"
Power supply board: C298PSB/PSE
"
Panel board: C304PNL
Refer to Figure 2-10 for the major connection of the boards and their
roles.
C304PNL Panel Board C304PNL Panel Board
C304MAIN Control Board C304MAIN Control Board
3.3V Regulator 3.3V Regulator
+42VDC
Power OFF +5VDC
C298PSB/PSE Power C298PSB/PSE Power
Supply Board
Supply Board
Figure 2-10. Electric Circuit of Stylus COLOR 860/1100
OPERATING PRINCIPLES
Printer Mechanism Printer Mechanism
CR Motor
PF Motor
ASF/Pump Motor
Head Driver Circuit
Sensors
Electrical Circuit Operating Principles

2.2.1 C298PSB/PSE Board

The power supply board for the Stylus Photo 870 and Stylus Photo 1270 is
C298PSB/PSE. It uses a RCC switching regulator system, and supplies
+42VDC and +5VDC to the printer mechanism and control board.

2.2.1.1 Electrical Circuit

The table below shows the voltages produced in this circuit and their
applications.
Table 2-7. Application of the DC Voltages
Voltage
• CR Motor
+42VDC ± 2VDC
• ASF/Pump Motor
Rated output current: 0.5 A
• PF Motor
Maximum current: 1.4 A
• Head driving power supply
• Logic sensor circuit
• Panel LED
+5VDC ± 0.25VDC
• Nozzle selection circuit (on the printhead)
Rated output current: 0.5 A
Maximum current: 0.6 A
• I/F control circuit
• Slave CPU for DC motor control
NOTE: The 5VDC is only applied to the parts and locations shown in the
table above. The C304MAIN uses 3.3V drive chips for most of the
logic-line chips (CPU, ASIC, ROM, DRAM). For this reason, those
chips are not driven by the +5VDC produced by the but power supply
board but the 3.3VDC that is reduced by the 3.3VDC regulator on the
C298PSB/PSE.
Revision B
Application
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