Heater Lamp Control Circuit - Kyocera FS-1800 Service Manual

Heater lamp control circuit

The heater lamp control circuit turns the heater lamp on and off which is located coaxially inside
the heat roller. The surface of the roller maintains the constant temperature needed to permanently
fuse the toner on paper.
The heater lamp is directly fed with AC primary power (120 V or 220 - 240 V) which is supplied
from the power supply unit.
HEATON*
THERM
PC
TRC
AC
Power supply unit
+5V1
R217
2.2k
+
R219
3.3k
Q204
+5V1
R233
1M
2 −
393
3
+
R228
1.3k
Thermisor
Heater lamp
Figure 4-3-9 heater lamp control circuit
Engine board
+5V1
+5V1
8
−
6
7
393
5 +
U205-2
4
3
2
1
+5V1
U205-1
1
+5V1
Fuser board
4-31
+5V1
QA201B
4
5
3
HEATON
6
2
1
QA201A
HTEMP*
THDEAD
THERM
FS-1800/1800N | FS-3800/3800N
Engine
gate
array
(U204)
4
HEATON
CPU
(U201)
63
P43/PPG3
54
P34/RT04
/HRQ
3
P50/AN0