Technical data

1.10 Fixing Heater Control Circuit
1.10 Fixing Heater Control Circuit
The fixing unit heater is maintained at a temperature of 120°C (248°F) in the
standby mode. When a print command is received, the temperature is raised
to the 150°C (302°F) operating temperature. Figure 1–13 shows an overall
diagram of the fixing unit control circuits.
Figure 1–13 Fixing Heater Diagram
DC Control Board
J212-9
+5 V
FSRDRV
FSRTH
J209-3
-4
M1
Main Motor
Thermistor (TH1)
Upper Roller
Lower Roller
MLO-006186
Thermoswitch (TP2)
Thermoswitch (TP1)
Fixing-Roller
Heater (H1)
Print Paper
Lower Roller
Upper Roller
LVPSA
Fixing Roller
Heater Drive
SSR
The signal is an analog signal that increases with the temperature
of the fixing roller. Heat from the upper roller increases the resistance of the
thermistor (TH1) which increases the voltage of .
The DC control board measures and outputs the control signal
to the fixing roller heater driver circuit in the LVPSA. A solid state
relay (SSR) is used to turn the fixing heater current on and off.
Physical and Functional Description 1–23