Circuit Description; Engine Controller - Samsung ML-1610XBH Service Manual

12
12

1 2. Circuit Description

12.1 Engine Controller

The engine controller module consists of a motor controller, a PWM controller, a LSU I/F controller, and an ADC I/F
controller.
12.1.1 Heater Control
ENGINE CONTROL PART
FUSER
Vcc
THERM Rs
D2
914T1
The heat lamp radiates heat by using AC power. The AC power is a TRIAC (a semiconductor switch device) which
controls a switch. The 'ON/OFF' control is completed by turning on/off a gate of the TRIAC through a photo TRIAC
which is insulation part.
If explaining more detail about the AC control part, it consists of passive circuit ; therefore, it turns on/off the heater
by receiving the signal from the engine control part. If the heater on signal is turned on at the engine, electricity flows
in as the LED of the PC1 (Photo TRIAC) is connected. Then, it emits light.
By this light, the TRIAC unit, a light receiving unit, becomes on, and electricity is supplied to the gate of the TRIAC.
Then, the TRIAC is turned on. As a result, AC current flows in a heat lamp, and the heat lamp radiates heat.
On the other contrary, if the signal is turned off, the PC1 becomes off, and the TRIAC is turned off due to no elec-
tricity at the gate of the TRIAC. Consequently, the heat lamp is turned off.
Special Feature of TRIAC (THY 1): 16A, 600V SWITCHING
Phototriac Coupler (PC3)
Turn On If Current: 15mA~50mA (Design: 16mA)
High Repeive Peak Off State Voltage: Min 600V
Samsung Electronics
Vcc
R3
IC1
LM393D
3
Vcc
1
D1
2
914T1
R5
R4
R1
5.6K
C
TR1
C1
B
R2
KSC
10nF
1008-Y
C2
E
1nF
R6
5.6K TR2 KSC
1008-Y
C
B
D3 R7
E
914T1 1K
R21
1.5K
CN1
BD2
1
BD1
2
THERMISTOR
+24Vs
AC CONTROL PART
R22 180
FUSIBLE
PC1
2
1
TRIAC
C21
104
R23
100
Circuit Description
CHOKE
H
AC
VOLTAGE
N
R24
120
HEAT
C22
LAMP
103
Service Manual
12-1