Read Sharp R-741M (serv.man2) Service Manual online
9
741M -
TOUCH CONTROL ASSEMBLY/ DESCRIPTION OF LSI
Pin No.
Signal
I/O
Description
20.0 msec
H : 0V
L : -5V
A
B
0.1 sec.
2 sec.
H : 0V
L: -5V
H : 0V
L: -5V
(Grill or dual)
ON
OFF
During
cooking
L : -5V
0V
H :
(Grill or dual)
ON
OFF
During
cooking
L : -5V
0V
H :
34
BZ
OUT
Signal to sound buzzer (2.0 kHz).
A: key touch sound.
B: Completion sound.
35
R00
OUT
Terminal not used.
36
R01
OUT
Grill heating element driving signal.
To turn on and off the grill heating element
relay (RY2). "L" level during grill cooking
or dual cooking; "H" level otherwise.
relay (RY2). "L" level during grill cooking
or dual cooking; "H" level otherwise.
37
R02
OUT
Magnetron high-voltage circuit driving signal.
To turn on and off the cook relay
(RY3). In 100% POWER op-
eration, the signals hold "L"
level during microwave cooking
and "H" level while not cooking.
In other cooking modes (70%,
50%, 30%, 10%) the signal turns
to "H" level and "L" level in
repetition according to the power
level.
(RY3). In 100% POWER op-
eration, the signals hold "L"
level during microwave cooking
and "H" level while not cooking.
In other cooking modes (70%,
50%, 30%, 10%) the signal turns
to "H" level and "L" level in
repetition according to the power
level.
38
R03
OUT
Oven lamp, fan motor and turntable motor driving signal.
To turn on and off shut off relay (RY1). The
square waveform voltage is delivered to
the RY1 driving circuit.
square waveform voltage is delivered to
the RY1 driving circuit.
39
P20
IN
Signal coming from tact switch.
When either of tact switches SW64-SW66 is touched, a corresponding signal out
of SEG1, SEG2 and SEG3 will be input into P20. When no tact switch is touched,
the signal is held at "H" level.
of SEG1, SEG2 and SEG3 will be input into P20. When no tact switch is touched,
the signal is held at "H" level.
40-41
P21-P22
OUT
Terminal not used.
42
P23
IN
Signal coming from tact switch.
When either of tact switches SW60-SW62 is touched, a corresponding signal out
of SEG0, SEG1, SEG2 and SEG3 will be input into P23. When no tact switch is
touched, the signal is held at "H" level.
of SEG0, SEG1, SEG2 and SEG3 will be input into P23. When no tact switch is
touched, the signal is held at "H" level.
43
INT0
IN
Signal synchronized with commercial power source frequency.
This is the basic timing for time processing
of LSI.
of LSI.
44
INT1
IN
Connected to VC. (-5V)
45
K02
IN
Connected to VC. (-5V)
46
K03
IN
To input signal which communicates the door open/close information to LSI.
Door open "L" level signal (-5V). Door close "H" level (0V)
47
COM0
OUT
Common data signal: COM0.
Connected to LCD. (C1)
48
COM1
OUT
Common data signal: COM1.
Connected to LCD. (C2)
49
COM2
OUT
Common data signal: COM2.
Connected to LCD. (C3)
50
COM3
OUT
Terminal not used.
ON/OFF time ratio in Mi-
cro cooking
(a. 32second time base)
cro cooking
(a. 32second time base)
ON/OFF time ratio in Mi-
cro cooking
(a. 48second time base)
cro cooking
(a. 48second time base)
MICRO
ON
OFF
COOK
100%
100%
32sec.
0sec.
70%
24sec.
8sec.
50%
18sec.
14sec.
30%
12sec.
20sec.
10%
6sec.
26sec.
MICRO
ON
OFF
COOK
100%
100%
48sec.
0sec.
70%
36sec.
12sec.
50%
26sec.
22sec.
30%
16sec.
32sec.
10%
8sec.
40sec.
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