Epson Perfection 4870 Photo - Power Supply Circuit

Perfection 4870 Photo Revision A
OPERATING PRINCIPLES Power Supply Circuit 26
2.3 Power Supply Circuit
This Power Supply Circuit Board generates DC power necessary to drive the Control
Board and Scanner Engine. Table 2-1 indicates the Power Supply Circuit Boards on a
destination basis.
The output of the Power Supply Circuit Board is provided by closing/opening the No. 4
pin of the CN102 Connector. When the pin is open, the output voltages indicated in
Table 2-2 become active. The output voltages have their respective overcurrent
protection and overvoltage protection circuit functions.
NOTE 1:
If any of the outputs shuts down, all the other outputs also shut down.
2:
The input OFF time necessary for recovery is 5 minutes (maximum).
Table 2-1. Destination-based Power Supply Circuit Boards
Specifications Unit Part No. Fuse Rating
100-120VAC region 2027705 2.5 A/125 VAC
220-240VAC region 2027704 T2.5AH/250 VAC
Table 2-2. Power Supply Circuit Board Outputs and Protective Functions
Output
Voltage
Output
Current
Overcurrent Protection
(Protective circuit
operation current value)
Overvoltage Protection
(Protective circuit
operation voltage value)
5 VDC 1.2 A
Voltage droop with
current decrease.
Automatic recovery.
(1A or less)
Shutdown. Switch
power off, then on again
to recover. (5.5 to
7.5VDC)
12 VDC 0.2 A
Depending on the
drooping characteristic of
the regulator. Automatic
recovery. (0.5A or less)
Shutdown. Switch
power off, then on again
to recover. (14 to
17VDC)
24 VDC 0.7 A
Shutdown. Switch power
off, then on again to
recover.
Shutdown. Switch
power off, then on again
to recover. (28 to
33VDC)