Various Control Mechanisms; Fixing Temperature Control - Canon LBP3250 Series Service Manual

2.8.2 Various Control Mechanisms

2.8.2.1 Fixing Temperature Control

2.8.2.1.1 Fixing Temperature Control

The fixing temperature control is to keep the fixing heater in the fixing film unit to the specified temperature.
The engine controller monitors the fixing heater temperature detection signal (FSRTH) and outputs the fixing heater drive signal (FSRD) according to the detected
temperature.
The fixing heater drive PCB controls the fixing heater according to this signal to keep the fixing heater temperature within the target values.
Engine controller
CPU
FREQSNS
FSRD
24VOFF
FSRTH
Fixing heater (H1)
Pressure roller
Thermal fuse (TP1)
There are 8 types of target fixing temperature depending on the fixing mode.
These types are according to the paper type settings and resolution settings on a driver.
Settings on Printer Driver
Paper type settings
Plain paper
Plain paper L
Thick paper
Thick paper H
Transparency
Postcard/postcard H
Envelope
Labels
Low-voltage
power supply
FU101
Frequency
detection
circuit
(220-240V model only)
Thermistor (TH1)
Fixing film
Resolution settings (sub scanning)
600 dpi
600 dpi
600 dpi
600 dpi
600 dpi
600 dpi
600 dpi
600 dpi
Fixing control
RL101
Fixing heater
drive circuit
F-2-24
T-2-3
Target fixing temperature
175 to 170 deg C
160 to 165 deg C
185 to 195 deg C
190 to 195 deg C
160 to 165 deg C
193 to 198 deg C
175 to 180 deg C
185 to 195 deg C
Chapter 2
+24V
Relay drive
circuit
Fixing heater
safety circuit
0019-9537
2-23