Electrical Circuit Operating Principles; C424 Psb/Pse Board - Epson Stylus Color C70 Service Manual

EPSON Stylus COLOR C70/C80

2.2 Electrical Circuit Operating Principles

The electric circuit of the Stylus COLOR C70/C80 consists of the following boards.
Main board: C424 MAIN-B Board
Power supply board:

C424 PSB/PSE Board

This section provides operating principles of C424 Main-B Board and C424 PSB/PSE
Board. Refer to Figure 2-25 for the major connection of the each boards and their
roles.
Panel
C424 MAIN-B
+5VDC
+3.3VDC
PE Actuator
via IC9
+5VDC
+42VDC
C424 PSB/PSE Board
Figure 2-25. Electric Circuit
Operating Principles
Printer Mechanism
CR Motor
PF Motor
Head Driver Board
1. CSIC
2. CR ENC.
3. PF ENC.
4. Head Temp.
Electrical Circuit Operating Principles
2.2.1 C424 PSB/PSE board
The power supply boards of Stylus COLOR C70/C80 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 2-4. Application of the DC Voltages
Voltage
• Motors (CR Motor, PF Motor)
+42VDC • Printhead common voltage
• Printhead drive voltage
• Source of C424 MAIN-B logic (Actually 3.3VDC is used.)
+5VDC
• Source of 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
51