EPSON Stylus Scan 2500 Revision A
Operating Principles Electrical Circuit Operating Principles 55
2.5.1 B102 PSB/PSE Board
The power supply board for the EPSON Stylus Scan 2500 generates +42VDC
to drive the motors, +24VDC to drive the scanner and option, +12VDC to
power the lamp, and +5VDC/+3.3VDC to power the printer logic. The table
below shows application of voltages generated by PSB/PSE board.
1. Even if power is turned off during the middle of a print job, since the
driving power is turned off after the carriage goes back to the carriage
lock position, the possibility of clogged ink nozzles is reduced.
2. If power is turned off while paper is being fed in the printer, the same
operation mentioned above is performed and the driving power is turned
off after the paper is completely ejected. The time allowed is
approximately 30 seconds, meaning voltage is flowing for 30 seconds
after the power is turned off.
Figure 2-22 shows a block diagram of power supply board. The process from
the input of AC voltage to the output of DC voltage is explained in the
following pages.

Application of DC Voltage

Voltage Application
Printer Scanner
+42VDC
CR Motor
PF/Pump Motor
Printhead drive
+24VDC Scanner Motor
Option unit drive
+12VDC Inverter board
CCD sensor board
+5VDC
Common
Control circuit
Sensors (CR HP, PE, ASF)
Control panel
Printhead control
Option unit logic
+3.3VDC Control circuit