HTTP://BBS.FIXCLUB.COM.CN
23
JUL 2002
Edition 1.0
DP-1510P/1810P
/1810F/2010E
5. Fuser Temperature Control Circuit
The fuser temperature is controlled by IC1 on the LPC3 PC Board, which contains A/D (Analog/Digital)
converters. IC1 adjusts temperature, observing Thermistor and voltages separated by R61 with A/D
converters. When the PC101 drive current is transmitted from the LPC3 PC Board to the HTC PCB,
the Fuser Lamp turns ON. IC5 is a converter with open output at pins 1 and 7 and is used as an
abnormal temperature detection circuit. IC5, pin 1 and 7, has a high impedance when Q7 and Q8 are
activated, turning ON the Fuser Lamp. An abnormal temperature is detected when the VTH voltage
level becomes lower than V-, forcing IC5, pin 1 and 7 Low and deactivating Q8.
Abnormally low and high temperatures, as well as Thermistor release status, are detected by IC1
(CPU) programming.
Thermistor
(Fuser)
PC101
R61
VTH
GND
IC5
uPC393
IC1
IC1
THERM
(A/D)
L: ON
nSSRA
H: OFF
+5V
+5V
+5V
+5V
+5V
+5V
+5V
+5V
V-
Q23
Q24
Q7
Q8
R25
Q3
(HTC PCB)
Fuser Temperature Control Circuit
CN708