11.5 FUSING LAMP CONTROL CIRCUIT
The main board monitors the fusing temperature through a thermistor. It also
uses the zero cross signal generated by the dc power supply board to
accurately control the applied power.
Normally, the voltage applied to the lamp is a full ac waveform. However,
through SP29, fusing power can be phase controlled. (Normally, phase
control is used only if the customer has a problem with electrical noise or
interference.)
When the main switch is turned on, the main board starts to output a trigger
pulse [C], which has the same timing as the zero cross signal [B], to the ac
drive board. This trigger pulse allows maximum ac power to be applied to the
fusing lamp. When the operating temperature is reached, the CPU stops
outputting the trigger pulse (trigger goes HIGH) and the fusing lamp turns off.
Trigger Pulse
R263
R262
R270
+5V
IC103
+24V
+5V
CN122-18
CN122-4
CN122-6
CN122-2
CN435-7
CN435-3
CN435-5
CN137-14
R124
Zero Cross
CPU
TP103
(TH)
C151
R269
R268
24V
0V
Fusing
Thermistor
R414
R412
TRC402
CR402
RA401
Power Relay
Thermo-
fuse
Fusing
Lamp
AC115V/220V
T402
T405
T406
T407
PC402
RA401
Main Board (PCB1)
AC Drive Board (PCB2)
Q101
B
C
D
A
5
8
7
6
4
I/O
IC119
/230V/240V
CN137-15
CN435-1
CN437-6
To dc power
supply board
AC Power
Zero Cross
A
Trigger Pulse
Lamp Power
B
C
D
STM
2-80
FT4220/4222
Содержание FT4215
Страница 1: ...FT4220 4222 4215 SERVICE TRAINING MANUAL ...
Страница 12: ...SECTION 1 OVERALL MACHINE INFORMATION ...
Страница 28: ...8 AC POWER AND DC POWER DISTRIBUTION FT4220 4222 1 16 STM ...
Страница 31: ...SECTION 2 DETAILED SECTION DESCRIPTIONS ...
Страница 114: ...SECTION 3 DOCUMENT FEEDER ...
Страница 138: ...SECTION 4 SORTER ...
Страница 157: ...SECTION 5 DUPLEX ...