Power Supply Board - Epson Stylus Pro 3800 Service Manual

Epson Stylus Pro 3800/3800C/3850/3880/3885/3890

2.9.2 Power Supply Board

This section describes the power supply board that generates the power to operate this
printer.
CIRCUIT BLOCK DIAGRAM
The block diagram of C635 Power Supply board is shown below.
Pseudo-resonance type
Input Filter
separately-excited flyback
AC input
(Rush current
prevention
1. OCP function
circuit
2. OVP function
3. Secondary power
switch function
Figure 2-34. C635 Power Supply Board Block Diagram
CONTROL SIGNALS
There are three control signals between the C635/CA61 MAIN Board and the Power
Supply Circuit Board as shown in the table below.
Table 2-9. Control Signals
Signal Name Function Output
Power ON 39.9 to 44.1 V
PS Control
Signal (PSC)
Power OFF 3V or less
Normal
39.9 to 44.1 V
Operation
Energy Save
Signal (ESAVE)
Power Saving
15V Typ.
Operation
Overvoltage 0 V
Detection of
Detection Signal (Power is
overvoltage
(OVP) shutoff)
OPERATING PRINCIPLES
DC
+42V/0.7A
output
5VOVP
Control
signal
ESAVE
input
PSC
Remarks
The PS unit outputs the rated voltage.
The PS unit is instantly shut off.
The PS unit outputs the rated voltage.
It takes less than 500 msec to recover
from the power saving mode to the rated
voltage.
The power is shut off when the OVP
terminal voltage exceeds 7 V. To recover
from the status, lower the OVP terminal
voltage below 7 V, and reboot the printer
after reinserting the power plug into a
receptacle.
Outline of Circuit Boards
Revision C
59