Electrical Circuit Operating Principles; C417 Psb/Pse Board - Epson Stylus PHOTO 820 Service Manual

EPSON Stylus PHOTO 810/820

2.2 Electrical Circuit Operating Principles

The electric circuit of the Stylus C60 consists of the following boards.
Main board: C418 Main/Main-B Board
Power supply board:

C417 PSB/PSE Board

(Common board between both printers)
*1
: C418 Main/Main-B board is used for both the Stylus C60 and the Stylus Photo
810/820. Followings show you the specification of the C418 Main/Main-B board.
- For the Stylus C60
1) C418 Main : 2 in 1 ASIC + Soldering SOJ ROM (from the first mass production)
2) C418 Main/Main-B : 3 in 1 ASIC + Soldering SOJ ROM (Running change)
- For the Stylus Photo 810/820
1) C418 Main/Main-B : 3 in 1 ASIC + Soldering SOJ ROM
Note: CPU, ASIC and PROM is integrated as one chip (IC1) on the Main board.
This section provides operating principles of C418 Main board and C417 PSB/PSE
board. refer to Figure 2-15 for the major connection of the each boards and their roles.
C418 Main board
+5VDC +42VDC
C417 PSB/PSE board
Figure 2-15. Electric circuit
Operating Principles
*1
(from the first mass production)
Printer mechanism
CR motor
PF motor
Head driver board
HP/PE sensor
Electrical Circuit Operating Principles
2.2.1 C417 PSB/PSE board
The power supply boards of the Stylus PHOTO 810/820 uses 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 2-6. Application of the DC voltages
Voltage
• Motors (CR Motor, PF Motor)
+42VDC • Printhead common voltage
• Printhead nozzle selector 42V drive voltage
• C418 Main 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 A
Application
42