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17. Fusing section
Theory of operation ver. 1.0 July. 2006
66
magicolor 2490MF
Composition/Operation
17.3.3
Protection against abnormally high temperature
• The machine provides protection at three different stages to prevent abnormally high
temperature of the fusing Unit.
A. Soft protection
• If the thermistor detects a temperature exceeding a predetermined value, the malfunc-
tion code representing abnormally high temperature is displayed. At this time, the heater
lamp is turned OFF forcibly and the initiation of any new print cycle is prohibited (abnor-
mally high temperature detection control).
B. Hard protection
• If the CPU overruns and the output level of the CPU of the mechanical control board
becomes a HIGH or LOW level, and not a pulse output, and a predetermined tempera-
ture or higher is detected, a circuit within the mechanical control board turns OFF the
relay to shut down the power supply to the heater lamp.
C. Thermostat protection
• If neither the soft protection nor hard protection can detect an abnormally high tempera-
ture due to a defective thermistor or other reason, the thermostat operates at the speci-
fied temperature. This shuts down the power supply to the heater lamp, thus forcibly
turning it OFF.
Triac Circuit
Power Switch
Watchdog Circuit
A/D
FUSER WDT
RESET
Heater Remote
ON/OFF
Heating Roller
Fusing PressureRoller
Thermostat
Laser Safety Switch
Heater Lamp
Thermistor
GND
5V
Mechanical Control Board
CPU
Hard Protection
Circuit
4139to2097e0
Содержание Magicolor 2490 MF
Страница 1: ...SERVICE MANUAL 2006 07 2006 07 Ver 1 0 Ver 1 0 magicolor 2490MF THEORY OF OPERATION ...
Страница 3: ...ii ...
Страница 26: ...SERVICE MANUAL 2006 07 Ver 1 0 THEORY OF OPERATION Main Unit magicolor 2490MF magicolor 2490MF ...
Страница 41: ...5 Image creation process Theory of operation ver 1 0 July 2006 10 magicolor 2490MF Outline Blank Page ...
Страница 107: ...20 Other control Theory of operation ver 1 0 July 2006 76 magicolor 2490MF Composition Operation Blank Page ...
Страница 108: ...SERVICE MANUAL 2006 07 Ver 1 0 Auto Document Feeder Unit THEORY OF OPERATION ...
Страница 111: ...Auto Document Feeder Unit Outline Composition Operation Theory of operation ver 1 0 July 2006 ii Blank Page ...
Страница 115: ...3 Drive Theory of operation ver 1 0 July 2006 4 Auto Document Feeder Unit Composition Operation 3 Drive 4556T2C508AA ...
Страница 122: ...SERVICE MANUAL 2006 07 Ver 1 0 Lower Feeder Unit THEORY OF OPERATION ...
Страница 125: ...Lower Feeder Unit Outline Composition Operation Theory of operation ver 1 0 July 2006 ii Blank Page ...
Страница 127: ...1 Product specifications Theory of operation ver 1 0 July 2006 2 Outline Lower Feeder Unit Blank Page ...
Страница 129: ...3 Drive Theory of operation ver 1 0 July 2006 4 Lower Feeder Unit Composition Operation 3 Drive 4056T2C510AA ...
Страница 133: ...4 Mechanical operation Theory of operation ver 1 0 July 2006 8 Lower Feeder Unit Composition Operation Blank Page ...
Страница 134: ...SERVICE MANUAL 2006 07 Ver 1 0 Duplex Option THEORY OF OPERATION ...
Страница 137: ...Duplex Option Outline Composition Operation Theory of operation ver 1 0 July 2006 ii Blank Page ...
Страница 139: ...1 Product specifications Theory of operation ver 1 0 July 2006 2 Outline Duplex Option Blank Page ...