Operation - Sharp R-2110JK Service Manual

The following is a description of component functions during
oven operation.
OFF CONDITION
Closing the door activates the stop switch, primary interlock
switch and secondary interlock switch. (In this condition, the
monitor switch contacts are opened.)
When oven is plugged in, 120 volts A.C. is supplied to the
control unit. (Figure O-1).
1. The display will show flashing "88 : 88".
To set any program or set the clock, you must first
touch the STOP/CLEAR button. The display will clear,
and " : " will appear .
COOKING CONDITION
Program desired cooking time touching the NUMBER pads.
When the START button is touched, the following opera-
tions occur:
1. The contacts of relays are closed and components
connected to the relays are turned on as follows.
(For details, refer to Figure O-2)
RELAY CONNECTED COMPONENTS
RY1 Oven lamp / Fan motor / Stirrer motor
RY3, RY4 Hood fan motor
2. 120 volts A.C. is supplied to the inverter unit and is
converted in order to power of the magnetron by the high
frequency switching power circuit. The frequency is
approx. 33 _ 45 KHz.
3. The filament winding voltage of H.V. transformer heats
the magnetron filament and the H.V. winding gives a high
voltage approx. 2 KV to activaite a voltage doubler
circuit. Then approx. 4KV peak voltage power is supplied
to the magnetron cathode terminal.
4. The microwave energy produced by the magnetron is
channelled through the waveguide into the cavity feed-
box, and then into the cavity where the food is placed to
be cooked.
5. Upon completion of the cooking time, the inverter unit,
oven lamp, etc. are turned off, and the generation of
microwave energy is stopped. The oven will revert to the
OFF condition.
6. When the door is opened during a cook cycle, the monitor
switch, stop switch, secondary interlock switch and primary
interlock switch are activated with the following results.
The circuits to the stirrer motor, the cooling fan motor, the
turntable motor, and the inverter unit are de-energized,
and the touch screen displays the time still remaining in
the cook cycle when the door was opened.
7. The monitor switch is electrically monitoring the operation
of the secondary interlock switch and primary interlock
switch and is mechanically associated with the door so
that it will function in the following sequence.

OPERATION

DESCRIPTION OF OPERATING SEQUENCE
(1) When the door opens from a closed position, the
primary interlock switch and secondary interlock
switch open their contacts, and then the monitor
switch contacts close. And contacts of the relay
(RY1) remain closed.
(2) When the door is closed from the open position, the
monitor switch contacts first open and the stop
switch contacts open, and then the contacts of the
secondary interlock switch and primary interlock
switch close. And contacts of the relay (RY1) open.
If the secondary interlock switch and primary interlock
switch fail with their contacts closed when the door is
opened, the closing of the monitor switch contacts will form
a short circuit through the monitor fuse, secondary interlock
switch, primary interlock switch and relay (RY1) causing the
monitor fuse to blow.
VARIABLE COOKING
When Variable Cooking Power is programmed, the 120
volts A.C. is supplied to the inverter unit which is operated
by the control unit. Microwave power operation is as follows:
The oven can be set for any of 11 power levels: 0% to
100%(HIGH). The variable cooking power less than 40% is
programmed at the ratio of ON time and OFF time within 32
sec./ cycle time base.
CONNECTION BETWEEN POWER SETTING AND ON/
OFF TIME OF INVERTER UNIT.
OUTPUT POWER SETTING
Power 100%
Power 90%
Power 80%
Power 70%
Power 60%
Power 50%
Power 40%
Power 30%
Power 20%
Power 10%
Power 0%
Note: The ON/OFF time ratio does not correspond with
the percentage of microwave power, because
approx. 3 seconds are needed for heating of the
magnetron filament.
SENSOR COOKING CONDITION FOR R-2120J
Using the Sensor cooking function the food is cooked without
figuring time, power level or quantity. When the oven senses
enough steam from the food, it relays the information to its
microprocessor which will calculate the remaining cooking
time and power level needed for best results. When the food
is cooked, water vapor is developed. The sensor "senses"
the vapor and its resistance increases gradually. When the
7
R-2110JK
R-2110JW
R-2120JK
R-2120JW
ON TIME OFF TIME
Continue operation
26 sec. 6 sec.
22 sec. 10 sec.
16 sec. 16 sec.
8 sec. 24 sec.
0 sec. 32 sec.