Power Supply Circuit - Epson Perfection 1200U Service Manual

EPSON Perfection 1200

2.2 Power Supply Circuit

Power supply circuit in this scanner generates direct current DC power
necessary for driving the controller board and scanner engine. Table below
shows each power supply circuit for different destinations.
Table 2-1. Power Supply Circuit Board for Destination
Specification
100-120 VAC Range
220-240 VAC Range
Figure 2-5 shows diagram of power supply circuit.
Output from the power supply circuit is performed by closing or opening the No.
4 pin of CN102 connector. When opening, as it is shown in the Table below,
each output voltage becomes active. Also, each output voltage has over
current protection and over voltage protection circuit.
Table 2-2. Output and Protection Function
Output Output Over Current Protection
Voltage Current (Current value to activate)
Fold-back characteristic.
5 VDC 1.2A Automatic Recovery. (Less
Constant current limiting.
Automatic Recovery.
12 VDC 0.2A
(less than 0.5 A)
Shut down. Turn off the
24 VDC 0.7A power and back on to
NOTE: 1. If a part of output is shut down, all the other output are also shut
down.
2. Off time required to recover is maximum 5 minutes.
Operating Principles
Unit Part No. Fuse
2031592 2.5 A/125 VAC
2031593 T2.5AH/250 VAC
Over voltage Protection
(Voltage value to activate)
Shut down. Turn off the
power and back on to
than 1A) recover. (5.5 -7.5 VDC)
Shut down. Turn off the
power and back on to
recover. (14 -17 VDC)
Shut down. Turn off the
power and back on to
recover. recover. (28 -33 VDC)
Power Supply Circuit
Revision B
21