Error Detection - Canon ImageRunner 600 Service Manual

CHAPTER 8 FIXING SYSTEM
D.

Error Detection

The fixing temperature control mechanism is monitored for the following:
[1] Temperature control error by the main thermistor (TH1; see the sequence charts on the
pages that follow)
[2] Sensor error by the sub thermistor (TH2; see the sequence charts on the pages that follow)
[3] Overheating error by the thermal switch (TP1)
J508B
1
M-TEMP
7
0V
8
S-TEMP
9
0V
10
20
Main
heater
J505A
1
MHDTC
9
MH-ON
10
11
12
0V
13
24V
14
When '1', the main heater turns on.
J512A
1
24V
13
SW-OFF
14
Figure 8-305 Construction of the Control System
8-18
COPYRIGHT © 1999 CANON INC.
Voltage suited to the
temperature detected by the
main thermistor
Upper fixing roller
Thermal switch
Sub heater
At 223˚C, the AC
line is turned off
SH-ON
SSR
SHDTC
When the sub heater is powered, '0'.
When '0', the main switch is turned off.
Voltage suited to the
temperature detected by
the sub thermistor
Main thermistor
RLY
Relay
Main switch
CANON imageRUNNER 600 REV.1 JAN. 2000 PRINTED IN U.S.A.
Sub thermistor
Front door