Sharp R-7H55, Service Manual

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R-7H55
21
DESCRIPTION OF LSI
LSI(IZA573DR)
The I/O signal of the LSI(IZA573DR) is detailed in the following table.
Pin No. Signal I/O Description
1 R60 OUT Damper motor relay driving signal.
To turn on and off shut-off relay (RY6).
2 R61 OUT Convection motor driving signal.
To turn on and off shut-off relay (RY5). "L" level
during CONVECTION; "H" level otherwise.
3 R62 OUT Cooling fan motor driving signal.
To turn on and off shut-off relay (RY4). "L" level during
both microwave, convection cooking; "H" level otherwise.
4 R63 OUT 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 and relay (RY2,RY3,RY5) control
circuit.
5 R70 OUT Terminal not used.
6 R71 OUT Heating element driving signal.
To turn on and off heater 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.
7 R72 OUT Terminal not used.
8 R00 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
microwave cooking and “H” level while not
cooking. In other cooking modes (MED HIGH,
MED,MED LOW,LOW) the signal turns to
“H” level and “L” level in repetition according
to the power level.
9 R01 IN Input signal which communicates the door open/close information to LSI..
Door closed; "H" level signal.
Door opened; "L" level signal.
10 R02 IN Input signal which communicates the damper open/close information to LSI.
Damper opened; “H” level; signal (0V:GND).
Damper closed; “L” level; signal (-5V:VC).
11 R03 OUT Timing signal output terminal for temperature measurement(OVEN).
“H” level (GND) : Temperature measuring timing. (Convection cooking or dual cooking)
/ “L” level (-5V) : Thermistor OPEN timing.
12 TEST IN Connected to VC.
13 RESET 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.
14 OSC1 IN Internal clock oscillation frequency input setting.
The internal clock frequency is set by inserting the ceramic filter oscillation circuit with
respect to OSC1 terminal.
15 OSC2 OUT Internal clock oscillation frequency control output.
Output to control oscillation input of OSC2.
16 GND IN Connected to VC.
17/18 X1/X2 IN/OUT Terminal not used.
ON
OFF
During
cooking
L
GND H.
(Convection)
20 msec
During cooking
H
L
HIGH
MED HIGH
MED
MED LOW
LOW
ON
ON
ON
ON
ON
OFF
OFF
OFF
OFF
24 sec 8 sec
18 sec
14 sec
12 sec 20 sec
8 sec
24 sec
32 sec
L
H : GND
ON
OFF
During
cooking
L
GND H.
(Convection)
ON
OFF
L
H
ON
OFF
During
(cooking)
L
H