Epson Stylus Pro 3850 - Power Supply Board

Epson Stylus Pro 3800/3800C/3850/3880/3885/3890 Revision C
OPERATING PRINCIPLES Outline of Circuit Boards 59
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.
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 Remarks
PS Control
Signal (PSC)
Power ON 39.9 to 44.1 V The PS unit outputs the rated voltage.
Power OFF 3V or less The PS unit is instantly shut off.
Energy Save
Signal (ESAVE)
Normal
Operation
39.9 to 44.1 V The PS unit outputs the rated voltage.
Power Saving
Operation
15V Typ.
It takes less than 500 msec to recover
from the power saving mode to the rated
voltage.
Overvoltage
Detection Signal
(OVP)
Detection of
overvoltage
0 V
(Power is
shutoff)
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.
AC input
Input Filter
Pseudo-resonance type
separately-excited flyback
1. OCP function
2. OVP function
3. Secondary power
switch function
+42V/0.7A
5VOVP
ESAVE
PSC
DC
output
Control
signal
input
(Rush current
prevention
circuit