Electrical Circuit Operating Principles; Power Supply Circuit Operating Principles - Epson Stylus 1500 Service Manual

Operating Principles

ELECTRICAL CIRCUIT OPERATING PRINCIPLES

The Stylus 1500 contains the following circuit boards:
C172 MAIN board (main control circuit board)
C172 PSB/PSE board (power supply circuit board). This is the same board used in the Stylus
Color printer.
C172 PNL (control panel board)
In addition to the circuit boards above, part of the printhead drive circuit is built on a separate
circuit board installed in the carriage unit; the printhead is attached directly to this board. The
figure below shows a block diagram of the electrical circuitry.
C172 PSB/PSE
+5 V DC
+42 VDC
Figure 2-18. Electrical Circuit Block Diagram

Power Supply Circuit Operating Principles

The power supply circuit for this printer is provided either by the C172 PSB board (120 VAC) or by
the C172 PSE board (220-240 VAC). Both boards are identical in design and function, except for the
components in the primary circuit that accommodate the specified input voltage.
voltages and applications of output voltages are summarized in the table below.
Voltage
Motor drive (carriage and paper feed)
+42 VDC
Printhead (through the drive voltage generation circuit)
C172 MAIN board logic circuit
+5 VDC Sensors (home position, paper end, no ink cartridge, head thermistor)
C172 PNL control panel board, head nozzle selector
2-16
C172 PNL
C17 2 MAIN
Table 2-7. DC Voltage Distribution
Application
Mechanism Unit M-4E60
CR Motor
PF Motor
Carriage Unit
Color Head
Black Head
Drive Circuit
Drive Circuit
(Option)
The input
Rev. A