Fusing Temperature Protect Control - Konica Minolta bizhub 160 Service Manual

Theory of Operation Ver. 1.0 Apr. 2005
12.2.5

Fusing Temperature Protect Control

ANIN
CPU
FUSER_LAMP
FUSER_LAMP_
RY
Controller/Mechanical Control Board
<Soft protect>
• The comparator provided on the Controller/Mechanical Control Board is used as means
for detecting an abnormally high temperature through software approach. If the tempera-
ture detected by the Thermistor (voltage value) is greater than the comparative tempera-
ture 235 °C (voltage value), the triac relay is turned OFF to shut down the output of the
Heater Lamp.
<Hard protect>
• As a protection should there be a software failure, the Thermostat is used to shut down
current to the Heater Lamp when the temperature of the Fusing Roller becomes inordi-
nately high.
Electrical Component
TH1
Electrical Component
H1
Comparative
Voltage
Comparator
High-temperature
Protect Signal
Control Signal
Low temp.
PWB-P MPJ2P-1
Control Signal
PU-1 CN1PU-1-3
12. Fusing section
Fusing Unit
Thermistor (TH1)
Fusing Roller
Heater Lamp
Thermostat (TS1)
AC
T2
T1
Triac
Power Unit
WIRING DIAGRAM
High temp.
Analog Input
ON OFF WIRING DIAGRAM
L H
4980M015AB
B-7
I-7
39