Sharp AM-900 Service Manual page 91

b) PC printing
• Temperature control is started when PC starts printing.
• Temperature is controlled at 200 °C. (Heater OFF over 200
°C. Heater ON below 200 °C.
• After printing, temperature is not controlled.
• Fan motor starts revolving from the beginning of temperature
control and stops 120 seconds after printing is finished.
Temperature control is not started from the start of printing
because the first copying time should be within 28 seconds.
In case of PC printing
(Single sheet/continuous)
200°C
Printing started
Temperature control started
HLON
FAN
Fig. 15
3.1.5 Electrical connection
Heater lamp: The 500W halogen lamp is used.
Thermistor: Thermistor of chip type with good response is
used to respond to rapid heating of the heat
roller.
Temperature fuse 1 Temperature fuse 1 is installed to the fusing
(152°C): cover. It blows off when the ambient temperature
of the fusing cover rises abnormally (152°C).
Temperature fuse 2 Temperature fuse 2 is in close contact with the
(216°C): heat roller. It blows off when the heat roller tem-
perature rises abnormally high (216°C).
The heat roller surface temperature is maintained to the optimum level
by controlling ON/OFF of the heater lamp according to the tempera-
ture data (voltage) from the thermistor. The heat roller surface temper-
ature is controlled to 200°C. Two temperature fuses are provided to
protect the heat machine from an abnormally high temperature in the
fusing section. The heater lamp is lighted by the AC power.
Printing finished
OFF
CONTROL PWB
16bit
CPU
IC32
HLON-
71
(IC21) 6 11
73 PWRLY PW RLY-
75 RTH CIRCUIT
+5V
CNRTH
1 +5V
2 RTH
CNPW
POWER PWB
CN HT
PC2
3 L
TRA1
RL1
CNHT
1 N
CNAC
3 ACN
1 ACL
+24VS +24VMAIN
CN6
1 +24VMAIN
3 +24VS
Fig. 16
5 – 18
Temperature
fuse 1 (152°C)
Heater
lamp
Temperature
fuse 2 (216 ° C)
Thermistor
AM-900U