Controlling The Fixing Temperature - Canon imageRUNNER 330 Service Manual

CHAPTER 9 FIXING SYSTEM
C. Controlling the Fixing Temperature
1. Outline
The temperature of the copier's upper fixing roller is monitored by the main thermistor (TH1)
and the sub thermistor (TH2), and is controlled by the DC-CPU*, which varies the main heater
drive signal (H1-D) and the sub heater drive signal (H2-D) according to the levels of TH1 and TH2.
Image processor PCB
DC controller PCB
DC
-CPU
Figure 9-103 Major Parts Used for Fixing Temperature Control
9-6
COPYRIGHT © 1999 CANON INC. CANON imageRUNNER 400/330 REV.0 JAN. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
RL-D
Upper fixing roller
TH1-S
TH1
TH2
TH2-S
H1-D
H1-ERR
Error
detection
H2-ERR
circuit
H2-D
0V
Door switch
RL1
THSW1
SW2
SW1
H1 H2
SSR
Main power
switch
Leakage
power
breaker