Sharp R-775W - Medium High, Medium, Medium Low, Low Cooking; On;Off Time Ratio

R-775(W)R-785(AL) - 10
power, the line voltage is supplied to the high voltage
transformer intermittently within a 32-second time base
through the relay contact which is coupled with the cur-
rent-limiting relay RY2. The following levels of microwave
power are given.
Note: The On/Off time ratio does not exactly correspond
to the percentage of microwave power, because
approx. 3 seconds are needed for heating up the
magnetron filament.
GRILL COOKING CONDITION
TOP GRILL (Figure O-3a)
In this condition the food is cooked by the top grill heating
element . Rotate the COOKING MODE dial to TOP
GRILL setting. And enter the desired cooking time by
rotating the TIME/WEIGHT dial. When the START button
is pressed, the following operations occur:
1. The numbers of the digital readout start the count down
to zero.
2. The oven lamp, cooling fan motor and turntable motor
are energized.
3. The relay RY3 is energized and the main supply
voltage is applied to the top grill heating element.
4. Now, the food is cooked by the top grill heating ele-
ment.
BOTTOM GRILL (Figure O-3b)
In this condition the food is cooked by bottom grill heating
element energy. Rotate the COOKING MODE dial to
BOTTOM GRILL setting. And enter the desired cooking
time by rotating the TIME/WEIGHT dial. When the START
button is pressed, the following operations occur:
1. The numbers of the digital readout start the count down
to zero.
2. The oven lamp, cooling fan motor and turntable motor
are energized.
3. The relay RY4 is energized and the main supply
voltage is applied to the bottom grill heating element.
4. Now, the food is cooked by the bottom grill heating
element.
TOP AND BOTTOM GRILLS (Figure O-3c)
In this condition the food is cooked by top and bottom grill
heating elements energy. Rotate the COOKING MODE
dial to TOP AND BOTTOM GRILLS setting. And
enter the desired cooking time by rotating the TIME/
WEIGHT dial. When the START button is pressed, the
following operations occur:
1. The numbers on the digital readout start the count
down to zero.
2. The oven lamp, cooling fan motor and turntable motor
are energized.
3. The relay RY4 is energized and the main supply
voltage is applied to the bottom grill heating element.
3. The relay RY3 is energized and the main supply
voltage is applied to the top grill heating element.
4. Now, the food is cooked by the top and bottom grill
heating element.
DUAL COOKING CONDITION
MICROWAVE AND TOP GRILL (Figure O-5a)
Rotate the COOKING MODE dial to setting. And
enter the desired cooking time by rotating the TIME/
WEIGHT dial. And press WATT button to set the desired
microwave power. When the START button is pressed,
the following operations occur:
1. The numbers of the digital readout start the count down
to zero.
2. The oven lamp, cooling fan motor and turntable motor
are energized.
3. The relay RY3 is energized and the main supply
voltage is applied to the top grill heating element.
4. The relay RY2 is energized and the microwave energy
is generated by magnetron.
5. Now, the food is cooked by microwave and top grill
simultaneously.
MICROWAVE AND BOTTOM GRILL (Figure O-5b)
Rotate the COOKING MODE dial to setting. And
enter the desired cooking time by rotating the TIME/
WEIGHT dial. And press WATT button to set the desired
microwave power. When the START button is pressed,
the following operations occur:
1. The numbers of the digital readout start the count down
to zero.
2. The oven lamp, cooling fan motor and turntable motor
are energized.
3. The relay RY4 is energized and the main supply
voltage is applied to the bottom grill heating element.
4. The relay RY2 is energized and the microwave energy
is generated by magnetron.
5. Now, the food is cooked by microwave and bottom grill
simultaneously.
ON/OFF TIME RATIO
In dual cooking, the magnetron operates within a 54
second time base. The following table is the ON / OFF time
ratio at each power output of the magnetron.
POWER OUTPUT ON TIME OFF TIME
100% 54 sec. 0 sec.
70% 40 sec. 14 sec.
50% 29 sec. 25 sec.
30% 18 sec. 36 sec.
10% 9 sec. 45 sec.
MEDIUM HIGH, MEDIUM, MEDIUM LOW, LOW
COOKING
When the microwave oven is preset for variable cooking
900W (HIGH) 
32 sec. ON
630W
MEDIUM 
 HIGH
Approx. 70%
100%
24 sec. ON 8 sec. OFF
14 sec. OFF
20 sec. OFF
26 sec. OFF
450W (MEDIUM) Approx. 50%
18 sec. ON
270W
MEDIUM 
 LOW
Approx. 30%
12 sec. ON
90W (LOW) Approx. 10%
6 sec. ON
OPERATION SEQUENCE