2.2 DRUM HEATER CONTROL
The drum thermistor monitors the drum surface temperature. When the
measured temperature reaches 41°C, the main PCB determines that the
copier is ready to make copies.
When the main switch is off, the drum heater relays (RA353 and RA354) are
off, so that the drum heater is controlled by the 65°C thermoswitch. The
thermoswitch is on at 50°C and off at 65°C.
When the main switch is on, RA354 is on and bypasses the 65°C
thermoswitch from the drum heater control circuit. RA353 turns on or off
according to the temperature detected by the drum thermistor.
The drum surface temperature is controlled between 41°C and 50°C.
To minimize the power consumption, RA353 is turned on to bypass the drum
heater during the copy cycle.
160°C 65°C
Drum Heater 1
Drum Heater 2
Drum
Heater 1
Drum
Heater 2
Drum Thermistor
Drum Heater
A/D
Converter
Drum Thermistor
Relay PCB
Main PCB
A171D509.wmf
31 July 1995
DRUM
2-17
Summary of Contents for FT8680
Page 3: ...SECTION 1 OVERALL MACHINE INFORMATION ...
Page 8: ...MEMO 31 July 1995 SPECIFICATIONS 1 5 ...
Page 23: ...6 5 IMAGE OVERLAY MODE 2ND SIDE A171V505 wmf PAPER PATH 31 July 1995 1 20 ...
Page 24: ...SECTION 2 DETAILED SECTION DESCRIPTIONS ...
Page 133: ...Timing Chart 1 Stack 2 Paper Feed A171D551 wmf A171D552 wmf 31 July 1995 DUPLEX 2 109 ...
Page 159: ...SECTION 3 INSTALLATION ...
Page 177: ...SECTION 4 SERVICE TABLES ...
Page 229: ...SECTION 5 REPLACEMENT AND ADJUSTMENT ...
Page 362: ...SECTION 6 TROUBLESHOOTING ...