Xerox Phaser 4500 Service Manual page 44

Theory of Operation
2-8
List of Sensors and interlocks
Name Type
Registration Mechanically
sensor actuated photo
sensor
Toner sensor Magnetic sensor
Exit sensor Mechanically
actuated photo
sensor
Output tray full Mechanically
sensor actuated photo
sensor
Temperature Soft Touch Sensor
sensor
Rear cover Microswitch
switch
24 V interlock Microswitch
Top cover switch Microswitch
(P4500 only)
Laser interlock Microswitch
(P4500 only)
5 V interlock Microswitch
Start of scan Photo
sensor
Fuser Thermostatic
thermostat(s) switche(s)
Stacker rear Microswitch
cover switch
Stacker sensor Mechanically
actuated photo
sensor
Function
Detects the paper as it
reaches the registration
rollers.
Detects the presence of
toner in the print cartridge.
Detects paper as it leaves
the fuser.
Detects when the standard
output tray is full.
Two of these monitor the
temperature of the Heat
roller.
Interrupts +24 V to the main
motor when the rear exit
cover is open; in series with
24 V interlock.
Interrupts +24 V to the main
motor when the top cover is
open; in series with rear
cover switch.
Interrupts INTERLOCK BEF
to indicate the top cover is
open.
Interrupts +5 V to laser
diode; in series with 5 V
interlock switch.
Interrupts +5 V to laser
diode. In series with laser
interlock.
Detects the laser beam at the
start of a scan.
Interrupt AC power to the
fuser heater in overtemp
condition; P4500: two
switches in series; P4510:
single switch.
Signals the HVPS/engine
logic board that the stacker
rear cover is open.
Senses the presence of
paper in the stacker.
Phaser 4500/4510 Service Manual
Reference
Page 2-10
Page 2-16
Page 2-16
Page 2-22
Page 2-27
Page 2-22
Page 2-30
Page 2-30
Page 2-30
Page 2-30
Page 2-30
Page 2-20
Page 2-22
Page 2-38
Page 2-38