User manual

95.08.23.11.31
Color LaserWriter 12/600 PS Basics & Theory 1–150
Power Supply
The power supply for the sheet feeder consists of +24 VDC generated
by the internal power source and +5 VDC supplied by the printer.
The power source in the printer uses a remote switch. The CPU in the
sheet feeder controller board outputs the
REMOTE signal to the power
source in accordance with a command from the printer and turns the
power supply on or off.
A voltage of +5 VDC is used by the sensors and the ICs in the sheet
feeder controller board, while +24 VDC is used to drive the motors and
the solenoids.
The right door switch (SW302) is on the sheet feeder controller board.
When the right door is opened, this switch is turned off to shut off +24
V supplied to the drive loads.
With the sheet feeder installed on the printer, the AC power supply is
sent to the power source in the printer via that in the sheet feeder. If the
power cable is connected to the AC inlet on the printer by mistake, the
AC power supply is not sent to the power in the sheet feeder, nor is +24
VDC for the feeder generated. Therefore, the sheet feeder controller
board monitors the supply of 24 VDC by the power source and if 24
VDC is not generated, it informs the mechanical controller CPU in the
printer of a sheet feeder +24 V failure. The mechanical controller noti-
fies the DC controller, which then reports an internal communication
failure to the I/O controller.
Door Switch
(SW302)
Motors
Solenoid
+24 VA
Sensors
+5V
Fuse
Power
Supply
Circuit
Noise
Filter
+24 VB
+5 V
AC
Power
Outlet
Phototriac
+24 VA
Power
Source
5 V
Power Source
in Printer
Sheet Feeder
Controller Board
Remote
IC30
+24 V
5 V
Mechanical
Controller
Board
in Printer
Sheet Feeder
Power Supply