Sanyo SBM-20 Service Manual page 7

4) Heater and
motor control circuits
"Circuit diagram
—
Q101
OVER
TEMPERATURE
PROTECTOR
T
I
r--J'
I&
al
-TT
I PH102
QI; +
~i ,
L—
R104 (o
L101
o
E
I I II I
C230V
I A I
A A
5(3H7
R105
-----
1
21
VDD
P60
P61
ICI
(J-13V
.Description of operation
(1)
Heater control circuit
When the voltage at pin 32 of the microcomputer (IC1 ) becomes Low (-5V), the signal will drive
transistor (TR4) ,transistor (QI 01 ) ,photo triac (PHI 01 ), and then triac (TR1 01 ) to operate the heater.
(2) Motor control circuit
When the voltage at pin 33 of the microcomputer (IC1 ) becomes Low (-5V), the signal will drive
transistor (TR3) ,transistor (Ql 02) ,photo triac (PH1 02), and then triac (TR1 02) to operate the motor.
5) Reset circuit
—
Circuit diagram
2'
VDD
IC2
R17
ICI
1
3 5
R16
3 —
{)
RESET
C7 +
C2
C9 +
42
Vss
(1) The reset circuit generates the signal which resets the microcomputer.
6