Electrical Circuit Operation Principles; C202 Psb/Pse Board - Epson Stylus COLOR 800 Service Manual

2.3 Electrical Circuit Operation Principles

This printer consists of the following circuit boards:
†C202 MAIN board
†C202 PSB/PSE board
†C202 Panel board
In addition to the circuit boards above, the printhead driver circuit is directly attached to each of the black
and color heads in the CR unit. This section describes the operational principle of the C202 PSB/PSE
board and C202 MAIN board. Table 2-10 shows the input voltages and applications.

2.3.1 C202 PSB/PSE board

The electrical circuit of this printer uses RCC (Riging Choke Converter) which outputs 2 different types of
the VDC necessary to operate the printer.
The power switch of this printer is in the secondary circuit that allows the PSB/PSE board to continue to
supply voltage for the power and logic lines for a minimum of 20 seconds until the printhead returns to the
capping position even if the printer is turned off during printing. This extra time prevents ink leakage and
dried printhead caused by the printhead being left uncapped. The AC voltage from the AC inlet is first
input to the filter circuit for higher harmonics absorption and is then input to the rectification and smoothing
circuit, converting into DC voltage. This DC voltage is then input to the switching circuit. Along with this
switching operation by FET on the primary side, +42 voltage is generated and stabilized on the secondary
side, which is then converted into the stable +5 VDC by the chopping regulator IC.
Figure 2-15 shows the block diagram of the electrical circuit.
Rev. A
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Figure 2-14. Electrical Circuit Block Diagram
Table 2-10. DC Voltage Distribution
VDC
‰ Motors
+42 V
‰ Printhead common voltage
‰ C202 MAIN control board (logic)
+5 V
‰ C202 panel board
‰ Sensors
(HP sensor, ASF HP sensor, PE sensor)
Operating Principles
Application
2-13