Sharp R-671(B) Service Manual page 22

DESCRIPTION OF LSI
Pin No. Signal
12 P56 OUT
13 P55 OUT
14 P54 OUT
15 P53 OUT
16 P52 OUT
17 P51 OUT
18 P50 OUT
19 P47 OUT
20-22 P46-P44 OUT
23 INT1
24 INT0
25 P41
26 P40
...
CONT
I/O
Oven lamp and turntable motor driving signal(Square Waveform : 50Hz).
To turn on and off shut-off relay (RY1).
The square waveform voltage is
delivered to the relay (RY1) driving
circuit .
Terminal not used.
Signal to sound buzzer.
A: key touch sound.
B: Completion sound.
Touch control transformer driving signal.
To turn on and off the shut off relay ( RY6). If the oven has not been used for more
than 2 minutes, the relay RY6 will be turned off. The relay RY6 will be turned on
when the oven door is opened and closed.
Fan motor driving signal.
To turn on and off the fan motor relay RY5.
"L" level during cooking, or for 5 minutes
after grill cooking or dual cooking. "H" level
otherwise.
Grill heater (TOP HEATER) driving signal.
To turn on and off the grill heater relay
(RY3). "L" level during grill (TOP GRILL,
TOP AND BOTTOM) cooking or dual
(MICRO+TOP) cooking. "H" level
otherwise.
Bottom heater driving signal.
To turn on and off the bottom relay (RY4).
"L" level during grill (BOTTOM HEATER,
TOP AND BOTTOM) cooking or dual
(MICRO+BOTTOM) cooking. "H" level
otherwise.
Magnetron high-voltage circuit driving signal.
To turn on and off the cook relay
(RY2). In 100% POWER
operation, 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.
Terminal not used.
IN Signal coming from encoder.
When the encoder is turned, the contacts of encoder make pluse signals. And
pulse signals are input into INT1.
IN Signal to synchronized LSI with commercial power source frequency
(50Hz).
This is basic timing for time processing of LSI.
IN Signal coming from encoder.
Signal similar to INT1. Pulse signals are input into P41.
IN Connected to VC.
Description
ON/OFF time ratio in Mi-
cro cooking
(a. 32second time base)
MICRO
COOK
100%
70%
50%
30%
10%
R-671 - 21
20 msec
During cooking
0.12 sec
A
2.4 sec
B
OFF
ON
During cooking, or for 5 minutes
after grill cooking, or dual cooking
During
OFF
cooking
(Grill or dual)
ON
During
OFF
cooking
(Grill or dual)
ON
ON/OFF time ratio in Mi-
cro cooking
(a. 48second time base)
ON OFF MICRO
COOK
32sec. 0sec. 100% 48sec.
24sec. 8sec. 70% 36sec.
18sec. 14sec. 50% 26sec.
12sec. 20sec. 30% 16sec.
6sec. 26sec. 10%
20 msec
H
L
H: GND
L
H: GND
L
H.
GND
L
H.
GND
L
H. GND
L
ON OFF
0sec.
12sec.
22sec.
32sec.
8sec. 40sec.
H : GND
L (-5V)