Operation - Sharp R-6R50 Service Manual

OPERATION
DESCRIPTION OF OPERATING SEQUENCE
The following is a description of component functions
during oven operation.
(RD74101L)
OFF CONDITION
Closing the door activates all door interlock switches :
ist latch switch, 2nd latch switch, heater switch and
stop switch (In this condiction, the monitor switch
COM-INC contacts are opened.)
When oven ts plugged in, 220 volts A.C. is supplied to
CPU unit. (Figure 0-1)
The display will show blashing "88:88".
To set any program or set the clock, you must first
* touch ' (stop/clear) pad. The display will clear,
and 1:00 will appear and count up every minute.
NOTE: When the door is opened, the oven lamp comes
on.
COOKING CONDITION
FULL POWER COOKING
Program desired cooking time and Variable Cooking
Control by touching the time pads and (
MICROWAVE ) pad. When the (MINUTE
PLUS/START) pad is touched, the following oper-
ations 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
RY-1 Oven lamp/Turntable motor
RY-2 Power transformer
RY-4 Fan motor.
' RY-5 Rotisserie motor
Note: (1)The surge relay (not shown above table)
comes on only for 200 mili seconds directly
after 'MINUTE PLUS/START' pad touched,
with closing its contacts. After that, the surge
relay is. de-energied. and .its. contacs. are.
opened.
(2)The relay RY-5 is provided to Model R-GR50-
and R-6R70 only.
The rotisserie motor is activated only at the
(ROTISSERIE) pad is touched
befor touching the -
~ (MINUTE PLUS/START) pad,
2. 220 volts A.C. is supplied to the primary winding
of the power transformer and is converted to about
3.3 volts A.C. output on the filament winding, and
approximately 2000 volts A.C. on the high voltage
winding.
3. The filament winding voltage heats the magnetron
filament and the H.V. winding voltage is sent to a
voltage doubler circuit.
4, The microwave energy produced by the magnetron
is channeled 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 power
transformer, 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
switches operate as following.
2 ia
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|
|
|
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Switch Contact During Door
Cooking Opened
1st Latch Switch COM-NOQ Closed Open
2nd Latch Switch COM-NO Closed Open
Heater Switch -COM-NO Closed Open
Stop Switch COM-NO Closed Open
Monitor Switch COM-NC Open Closed
COM-NO Closed Open
The circuits to the turntable motor, the cooling fan
motor, the rotisserie motor (for R-6R50 and
R-6R70), and the high voltage components are
' deenergized, the oven lamp remains on, and the
digital readout displays the time stiJl remaining in
the cook cycle when the door is opened.
7. The monitor switch ts electrically monitoring the
operation of the ist latch switch and is mechan-
ically associated with the door so that it will func-
tion in the following sequence.
(1) When the door opens from a closed position,
the tst latch switch open that contacts, and
then the monitor switch contacts (COM-NC)
close.
(2) When the door is closed ae the open posi-
tion, the monitor switch (COM-NC) contacts
first open, and then the contacts of the 1st latch
switch close.
If the 1st latch switch fails with its contacts closed
when the door is opened, the closing of the monitor —
switch contacts (COM-NC) wili form a short circuit
through the fuse, 1st latch switch, causing the monitor
fuse to blow.
ROAST, SIMMER, DEFROST, WARM COOKING
When Variable Cooking Power ts programed, the 220
volts A.C. is supplied to the power transformer ~
intermittently through the contacts of relay(RY-2)
which is operated by the control unit within a 32 sec-
ond time base. Microwave power operation is as fol-
lows:
VARI-MODE ON TIME OFF TIME
FULL POWER . 32 sec. O sec.
(100% power)
ROAST 24 sec. 8 sec.
(approx. 70% Jeet
SIMMER 18 sec. 14 sec.
(approx. 50% power)
DEFROST 12 sec. 20 sec,
(approx. 30% power}
WARM , 6 sec. 26 sec.
(approx. 10% power)
Note: The ON/OFF time ratio does not correspond
with the percentage of microwave power, be-
cause approx. 2 seconds are needed for heating
of the magnetron filament.
EASY DEFROST COOKING
The EASY DEFROST key is a special function key to
defrost meats and other food faster and better.
EASY DEFROST automatically defrosts foods.
This key has 4 defrost stages.
When the food weight is entered by using the weight
pads, the oven will cook according to the special
cooking sequence, refer to Easy Defrost Chart on Op-
eration Manual.
GRILL COOKING CONDITION
In this condition the food is cooked by grill heating
element energy.
Program desired cooking .time and grill mode by
~ touching the time pad and (GRILL) pad.
When the (MINUTE PLUS/STAR) pad is
touched, the grill heating element etc. come on by ac-
tivating the relays, refer to Figure O-3 for details.
Note:
(1)For relay RY-5, refer to 'Note' of *Full Power Cook-
ing' section,
(2)The relay RY-4 contacts hold ON-condition and the
fan motor rotate for one minute after completion of
the grill cooking or dual cooking, and if the tem-
perature of the cooling thermal cut-out is higher
than 100 °C, the fan motor continues to rotate until
the temperature of the thermal cut-out becomes
lower than 80 °C.
DUAL COOKING CONDITION
(Model R-6G50,-6G52,-6R70)
In this condition the food is cooked by both microwave
energy and grill heating element energy simultane-
ously. Program desired cooking time and dual cooking ~
mode by touching the time pad and the (DUAL
COOK) pad.
When the (MINUTE PLUS/START) pad is
touched, the magnetron and the grill heating element ©
etc. come on by activating the relays, refer to Figure
O-5 for details.
COMPU COOK CONDITION |
COMPU COOK automatically selects the cooking
mode and compute the cooking timé for baking,
roasting and grilling. It is based on specific foods and
the quantity or weight of the food.
Program the COMPU COOK mode by touching
the (COMPU COOK) pad, enter the weight.
of the food by touching the or (weight)
pad or enter the quantity of the food by touching the
(weight) pad, and touch (MINUTE
PLUS/START) pad.
The oven will generate the microwave energy and/or
grill heating energy according to the programed special
cooking sequence.
R-6R5O(V
R-6G50(¥
R-6G52(¥
R-6R70(V