Service manual

EPSON Stylus COLOR 480 Revision B
Operating Principles Electrical Circuit Operating Principles 44
2.2 Electrical Circuit Operating Principles
The electric circuit of the Stylus COLOR 480 consists of the following boards.
o Main board: C367MAIN-B Board (C367MAIN Board*1)
o Power supply board: C367 PSB/PSE Board
NOTE: C367MAIN board is used for the product in the first mass production
and it will be changed to C367MAIN-B board at an early date.
The major difference is that C367MAIN-B has one chip CPU which
include the ASCI function. This section describes the operation
principle of C367MAIN-B
This section provides operating principles of C367MAIN-B Board and C367 PSB/PSE
Board. Refer to Figure 2-16 for the major connection of the each boards and their
roles.
Figure 2-16. Electric Circuit
2.2.1 C367 PSB/PSE board
The power supply boards of Stylus COLOR 480 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 2-7. Application of the DC Voltages
This printer dose not have the Power SW. So, the printer is turned on when the AC
cable is connected to the AC inlet. If the AC cable is disconnected from the AC inlet,
this power supply circuit supply 5 voltage for approximately 70us to keep the logic
circuit.
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.
C367 PSB/PSE
Board
+42VD C
+5VD C
C367 M AIN-B Board
Printer M echanism
CR Motor
PF M otor
H ead D river B oard
H P /P E /IC S e n s o r
Voltage Application
+42VDC
• Motors (CR Motor, PF Motor)
• Printhead common voltage
• Printhead nozzle selector 42V drive voltage
+5VDC
• C367MAIN control circuit logic
•Sensor