Sharp Warm & Toasty R-55TS, Service Manual, Page: 24 / 44

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R-55TS
DESCRIPTION OF LSI
LSI
The I/O signal of the LSI is detailed in the following table.
Pin No. Signal I/O Description
1-2 VL2-VL1 IN Power source voltage input terminal.
Standard voltage for LCD.
3-5 AN7-AN5 IN Terminal to change functions according to the model.
DC voltage in accordance with the model in operation is applied to set up its function.
6 AN4 OUT Terminal not used.
7 AN3 IN Terminal not used.
8 AN2 IN Input signal which communicates the door open/close information to LSI.
Door closed; “H” level signal.
Door opened; “L” level signal.
9 P61 OUT Terminal not used.
10 AN0 IN Temperature measurement input: OVEN THERMISTOR.
By inputting DC voltage corresponding to the temperature detected by the thermistor, this
input is converted into temperature by the A/D converter built into the LSI.
11 P57 IN Terminal not used.
12 P56 OUT Oven lamp and turntable motor driving signal(Square Waveform : 60Hz).
To turn on and off shut-off relay (RY1). The
square waveform voltage is delivered to the relay
(RY1) driving circuit.
13 P55 OUT Terminal not used.
14 P54 OUT Signal to sound buzzer.
A: key touch sound.
B: Completion sound.
C: When the temperature of the oven cavity
reaches the preset temperature in the
preheating mode, or when the preheating
hold time (30 minutes) is elapsed.
15 P53 OUT Magnetron high-voltage circuit driving signal.
To turn on and off the select relay. 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.
16 P52 OUT Fan motor driving signal.
To turn on and off the fan motor relay RY5. “L”
level during cooking, or after grill cooking or bake
cooking. “H” level otherwise.
17 P51 OUT Upper heater driving signal.
To turn on and off the upper heater relay (RY3).
“L” level during GRILL1, GRILL2 cooking or Bake
cooking. “H” level otherwise.
16.7 msec.
During cooking
H
L
A
B
0.1 sec.
2.0 sec.
B
1.0 sec. 1.0 sec.
H : GND
L
During cooking, after grill
cooking or bake cooking
H : GND
L ON
OFF
(During Grill1, Grill2 or Bake cooking)
H : GND
L ON
OFF
ON/OFF time ratio in micro cooking
(a 32 second time base)
MICRO
COOK ON OFF
100 % 32 sec. 0 sec.
70 % 24 sec. 8 sec.
50 % 18 sec. 14 sec.
30 % 12 sec. 20 sec.
10 % 6 sec. 26 sec.