User Guide

Fuser (fixing) temperature-control circuit
The temperatures of the two rollers in the fuser fluctuate according to the stage of the printing process.
The DC controller sends commands to the fuser-control circuit to adjust temperatures.
Figure 1-7 Fuser temperature-control circuit
Fuser
Fuser sleeve unit
Fuser
Fuser heater safety circuit
Fuser control circuit
Fuser
Fuser heater safety
circuit
Fuser heater
control circuit
Fuser (fixing) over-temperature protection
To protect the fuser from excessive temperatures, the product has four layers of protective functions. If
one function fails, the subsequent functions should detect the problem.
●
DC controller: When a thermistor or thermopile detects a temperature above a certain threshold,
the DC controller interrupts power to the specific heater. Following are the thresholds for each
component:
◦
TH1: 230° C (446° F) or higher
◦
TH2: 285° C (545° F) or higher
◦
TH3: 285° C (545° F) or higher
●
Fuser (fixing)-heater safety circuit: If the DC controller fails to interrupt the power to the
heaters at the prescribed temperatures, the fuser-heater safety circuit deactivates the triac-drive
ENWW
Engine-control system
17