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2001 CANON INC. 2000 2000 2000 2000 CANON iR2200/iR2800/iR3300 REV.0 MAR. 2001
CHAPTER 6 FIXING SYSTEM
6-9 P
3.3 Detecting Errors
The machine checks for the following in relation to its fixing temperature control mecha-
nism:
1. Temperature control error by main thermistor (TH1)
2. Temperature control error by sub thermistor (TH2)
The following signals are used in association with errors:
[1] Fixing temperature detection signal 1 (M_TH2): voltage output according to the reading
of the main thermistor.
[2] Fixing temperature detection signal 2 (S_TH2): voltage according to the reading of the
sub thermistor.
[3] Main heater drive signal: when ‘1’, the main heater goes ON.
[4] Sub heater drive signal: when ‘2’, the sub heater goes ON.
[5] Relay drive signal (RLY_1): when ‘1’, the relay (RL1) on the main power supply PCB
goes ON.
F06-303-01
+5V
+5V
+5V
TH1
Fixing main
thermistor
TH2
Fixing sub
thermistor
Heater relay circuit
A/D converter
(200V)
Thermal switch
(TP1)
Fixing main heater (H1)
Fixing sub heater (H2)
IC300
IC334
Switch PCB
RelayRL1
DC control PCB
Main power
supply PCB
[1]
[5]
[2]
[3]
[4]
High-
temperature
detection
circuit