Xerox Phaser 7400 Service Manual page 64

Microswitches
Microswitches are used primarily as paper size sensors and cover or door interlocks.
They are in a normally open state, and close when actuated. A bank of microswitches
is used to detect paper size in the universal trays.
Thermistors
Thermistors have a known value of resistance at a certain temperature. Used primarily
in the Fuser for temperature sensing.
Hall-Effect
Hall-Effect sensors detect the magnetic properties of the actuator. Hall-Effect sensors
are used to monitor activity of the Waste Toner Recovery system and Transfer Unit
belt. Use a magnetic source to actuate these sensors during testing.
List of Sensor and Interlock Types
Name
Level Sensor
No Paper
Paper Size
Registration
Color Registration
Feed-Out
Fuser Exit
Stack Full
Temperature
Door Interlocks
Low Toner
Fuser Thermostats
Offset Home
Temp/Humidity
Waste Toner
CRUM antenna
2-16
Type
Photo-receptive
Photo-receptive
Microswitch array
Photo-receptive
Photo-reflective
Photo-receptive
Photo-receptive
Photo-receptive
Thermistor
Microswitch
photo-reflective
Thermostatic switches
Photo-receptive
Integrated circuit
Hall-effect
RFID code reader
Phaser 7400 Color Printer Service Manual
Function
Detects paper stack height in Trays 2~6.
Detects no paper condition in all trays.
Detects the tray and the paper size.
Detects paper at the registration rollers.
Monitors color registration.
Detects paper leaving the feeder.
Detects paper as it leaves the Fuser.
Detects when the output tray is full.
Monitor Fuser roller temperatures.
Interrupts +24 V to the Motors.
Detects toner in the Imaging Units.
Interrupts AC power to the Fuser.
Detects Offset carriage position.
Monitors the printer's environment.
Monitors waste augers and transfer belt.
Communicates with the CRUMs.