Electrical Circuit Operating Principles; C383 Psb/Pse Board - Epson 680Pro - LQ B/W Dot-matrix Printer Service Manual

EPSON Stylus COLOR 680/777/77i

2.2 Electrical Circuit Operating Principles

The electric circuit of the Stylus COLOR 680/777/777i consists of the following
boards.
o Main board:
o Power supply board:
o Panel board:
This section provides operating principles of C383 Board and C383 PSB/PSE Board.
Refer to Figure 2-15 for the major connection of the each boards and their roles.
Figure 2-15. Electric Circuit
Operating Principles
C383 MAIN Board

C383 PSB/PSE Board

C383 PNL Board
Electrical Circuit Operating Principles
2.2.1 C383 PSB/PSE board
The power supply boards of Stylus COLOR 680/777/777i use a RCC (Ringing Chalk
Converter) circuit, which generates +42VDC for drive line and +5VDC for logic line to
drive the printer. The application of the output voltage is described below.
Table 2-5. Application of the DC Voltages
Voltage
• Motors (CR Motor, PF Motor)
+42VDC • Printhead common voltage
• Printhead nozzle selector 42V drive voltage
• C383MAIN control circuit logic
+5VDC
• Sensor
AC voltage input from AC inlet first goes through filter circuit that removes high
frequency components and is then converted to DC voltage via the rectifier circuit and
the smoothing circuit. DC voltage is then lead to the switching circuit and FET Q1
preforms the switching operation. By the switching operation of the primary circuit,
+42VDC is generated and stabilized at the secondary circuit. This +42VDC generated
by the secondary circuit is converted to +5VDC by the chopping regulator IC of the
secondary circuit.
Revision B
Application
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