Electrical - Xerox Phaser 4500 Service Manual

Electrical

Phaser 4500/4510 Service Manual
24 V interlock This safety switch interrupts 24 VDC from the LVPS to the
HVPS/engine logic board and main motor when the top cover is open. This
switch operates in series with the rear cover switch. See "Schematic Diagram
of Phaser 4500 Power Distribution and Interlocks" on page 2-31, or
"Schematic Diagram of Phaser 4510 Power Distribution and Interlocks" on
page 2-32.
5 V interlock This safety interrupts 5 VDC power from the LVPS to the LD
assembly of the laser assembly when the top cover is open. This interlock
works in series with the laser interlock. See "Schematic Diagram of Phaser
4500 Power Distribution and Interlocks" on page 2-31, or "Schematic Diagram
of Phaser 4510 Power Distribution and Interlocks" on page 2-32.
Rear cover switch
This safety switch interrupts 24 VDC from the LVPS to the
HVPS/engine logic board and main motor when the rear cover is open. This
switch operates in series with the 24 V interlock. See "Schematic Diagram of
Phaser 4500 Power Distribution and Interlocks" on page 2-31, or "Schematic
Diagram of Phaser 4510 Power Distribution and Interlocks" on page 2-32.
Main fan This vents air inside the printer to prevent an excessive rise in the
inside temperature.
Sub fan
This fan takes outside air into the printer to prevent an excessive rise
in the inside temperature. This is mounted near the laser assembly in the
center on the front side.
LVPS The low voltage power supply provides 5 V and 3.3 V for logic circuits,
5 V for the laser diode, and 24 V for motors and clutches. P4510: The LVPS
board includes the DC-DC converter (described below) as an integral part.
HVPS/engine logic board
The functions of the HVPS and engine controller are
brought together on a single circuit board. The HVPS provides high AC and
DC voltages to the BCR (charging), magnet roller (development), transfer
roller (transfer), and detack saw (peeling). The engine logic controls the
printing operation according to the information obtained through
communications with the image processor and from sensors and switches.
Image processor board
This receives data from the host computer, performs
printing, and controls the whole printer.
Exit motor PWBA This controls the exit motor assembly according to a signal
from the HVPS/engine logic board.
Interlock switch assembly
switches. See "Schematic Diagram of Phaser 4500 Power Distribution and
Interlocks" on page 2-31.
Top cover switch
P4500: This safety interlock interrupts the INTERLOCK BEF
signal between the LVPS and the HVPS/engine logic board to indicate
that the top cover is open.
Laser interlock P4500: This safety switch interrupts 5 VDC from the LVPS to
the LD assembly of the laser assembly when the top cover is open. This
switch operates in series with the 5 V interlock.
DC-DC converter
The DC-DC converter uses 24 V and 3.3 V from the LVPS to
supply 5 V and 3.3 V to the image processor board. By using the 24 V, the
DC-DC converter supplies additional power for the optional hard drive and
several other subcircuits.
P4500: The DC-DC converter is on a separate circuit board from the LVPS.
P4510: The DC-DC converter is an integral part of the LVPS.
This assembly consists of the following two safety
Theory of Operation
2-29