Service manual

33
R-1855A
18 P50 OUT Convection motor driving signal.
To turn on and off shut-off relay(RY7). "L" level during
CONVECTION; "H" level otherwise.
19 P47 OUT Hood lamp driving signal.
To turn on and off relay(RY8). "L" level: During Hood
lamp ON. "H" level: During Hood lamp OFF.
20 P46 OUT Hood motor driving signal.
To turn on and off relay(RY9). "L" level: During Hood
motor ON. "H" level: During Hood motor OFF.
21 P45 OUT Hood motor high / low driving signal.
To turn on and off relay(RY10). "L" level: During Hood
motor high. "H" level: During Hood motor low.
22 P44 OUT Timing signal output terminal for temperature measurement(OVEN).
"L" level (GND): Thermistor OPEN timing.
"H" level (-5V): Temperature measuring timing. (Convection cooking)
23 P43 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.
24 P42 IN Input signal which communicates the damper open/close information to LSI.
Damper opened; "L" level signal(0V:GND).
Damper closed; "H" level signal(-5V).
25 INT1 IN Signal to synchronize LSI with commercial power source freqency.
This is the basic timing for all real time processing of LSI.
26 P40 IN Connected to VC.
27 RST IN Auto clear terminal.
Signal is input to reset the LSI to the initial state when power is applied. Temporarily
set to "L" level the moment power is applied, at this time the LSI is reset. Thereafter set
at "H" level.
28 P71 OUT Magnetron high-voltage circuit driving signal.
To turn on and off the cook
relay(RY2). In P-HI operation, the
signals holds "L" level during mi-
crowave cooking and "H" level
while not cooking. In other cooking
modes (P-90,P-80,P-70,P-60,P-
50,P-40,P-30,P-20,P-10,P-0) the
signal turns to "H" level and "L"
level in repetition according to the
power level.
29 P70 OUT Heating element driving signal.
To turn on and off shut-off relay(RY3). "L" level during convection cooking; "H" level
otherwise. During convection cooking, the signal becomes
"H" level when the temperature of the oven cavity exceeds
the predetermined temperature.
30 XIN IN Internal clock oscillation frequency setting input.
The internal clock frequency is set by inserting the ceramic filter oscillation circuit with
respect to XOUT terminal.
Pin No. Signal I/O Description
ON
OFF
During
cooking
L
GND
H.
(Convection)
ON
OFF
H : GND
L
ON
OFF
H : GND
L
ON
OFF
H : GND
L
A
B
C
H: GND
L
0.1 sec
2 sec
1 sec
1 sec
H : GND
L (-5V)
16.7 msec
VARI-MODE ON TIME OFF TIME
P-HI (100% power) 32 sec. 0 sec.
P-90 (approx. 90% power) 30 sec. 2 sec.
P-80 (approx. 80% power) 26 sec. 6 sec.
P-70 (approx. 70% power) 24 sec. 8 sec.
P-60 (approx. 60% power) 22 sec. 10 sec.
P-50 (approx. 50% power) 18 sec. 14 sec.
P-40 (approx. 40% power) 16 sec. 16 sec.
P-30 (approx. 30% power) 12 sec. 20 sec.
P-20 (approx. 20% power) 8 sec. 24 sec.
P-10 (approx. 10% power) 6 sec. 26 sec.
P-0 (0% power) 0 sec. 32 sec.
ON
OFF
During
cooking
L
GND
H.
(Convection)