6
R-22GV
R-22GT
R-23GT
R-24GT OPERATION
DESCRIPTION OF OPERATING SEQUENCE
The following is a description of component functions during
oven operation.
OFF CONDITION
Closing the door activates the door sensing switch and
secondary interlock switches (1), (2). (In this condition, the
monitor switches (1) & (2) contacts are opened.)When the
oven is plugged in, and the rated voltage is supplied to the
control unit, (figure O-1), the display will show " . ".
IDLE CONDITION
When the door is opened, the contacts of the door sensing
switch open, initiating the following:
1. A signal is input to the control unit energizing the coil of
shut-off relay (RY-1).
2. The shut-off relay (RY-1) contacts close completing
circuitstoturnontheovenlamp,blowermotorandstirrer
motors.
3. If the door remains open, 60 seconds later the control
unit de-energizes shut-off relay (RY-1) turning off the
oven lamp, blower motor and stirrer motors.
When the door is closed, the door sensing switch contacts
close. With the closing of the door sensing switch contacts,
an additional circuit is provided which will permit the opera-
tion of the oven when one of the touch pads is depressed.
Since the control is enabled through the door sensing
switch, the door must be closed before the touch pads will
beeffective.Whenthe dooris closed,afull 60second IDLE
condition is always provided for selecting and pressing the
desired touch pads. A 60 second IDLE condition will also
follow the end of each cook cycle.
COOKING CONDITION
When the door is closed from the open position and Memory
pad is touched the, following will occur:
1. The contacts of relays are closed and components
connected to the relays are turned on (For details, refer
to Figure O-3)
2. Rated voltage is supplied to the primary winding of the
power transformer and is converted to about 3.3 volts
(forR-22GV, R-22GT) / 3.1volts (forR-23GT, R-24GT)
output on the filament winding, and approximately 2000
volts(forR-22GV,R-22GT)/ 2040volts(forR-23GT,R-
24GT) on the high voltage winding.
3. The filament winding voltage heats the magnetron
filamentandtheH.V.windingvoltageissenttoavoltage
doubler circuit.
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. Uponcompletionofthecookingtime, theovenwillrevert
to the IDLE condition.
6. When the door is opened during a cook cycle, monitor
switches (1) & (2), door sensing switch, secondary
interlock switches (1), (2) and primary interlock relays
(1), (2) are activated with the following results. The
circuitstothehighvoltagecomponentsarede-energized,
and the digital read-out displays " . " and cooking is
cancelled (in the case of Memory cooking).
7. The monitor switch (1) is electrically monitoring the
operation of the secondary interlock switch (1) and
primary interlock relay (1), and monitor switch (2) is
electrically monitoring the operation of the secondary
interlock switch (2) and primary interlock relay (2), and
monitor switches (1), (2) are mechanically associated
with the door so that it will function in the following
sequence.
(1)Whenthedooropensfromaclosedposition,thecontacts
of the primary interlock relays (1), (2) and secondary
interlockswitches(1),(2)open. Thenthemonitorswitch
contacts close.
(2)When the door is closed from the open position, the
monitorswitches(1),(2)contactsfirstopen,andthenthe
contacts of the secondary interlock switches (1), (2)
close.
Ifthesecondaryinterlockswitches(1),(2)andprimaryinterlock
relays (1), (2) fail with their contacts closed when the door is
opened,theclosingofthemonitorswitches(1),(2)contactswill
form a short circuit through the monitor fuse, secondary inter-
lock switches (1), (2) and primary interlock relays (1), (2),
causing the monitor fuse to blow.
VARIABLE POWER COOKING
( EXCEPT R-22GV)
When Variable Cooking Power is programmed, the rated
voltageA.C.issuppliedtothe powertransformerintermittently
through the contacts of relay (RY-2, RY-3). Relays RY-2 and
RY-3areoperated by thecontrol unit withinan interval second
time base. Microwave power operation is as follows:
POWER LEVEL ON TIME OFF TIME
100% 32 sec. 0 sec.
90% 30 sec. 2 sec.
80 % 26 sec. 6 sec.
70% 24 sec. 8 sec.
60% 22 sec. 10 sec.
50% 18 sec. 14 sec.
40% 16 sec. 16 sec.
30% 12 sec. 20 sec.
20% 8 sec. 24 sec.
10% 6 sec. 26 sec.
0% 0 sec. 32 sec.
Note: TheON/OFFtimeratiodoesnotexactlycorrespond
with the percentage of microwave power, because
approx. 2 seconds are needed for heating of the
magnetron filament.
Note: R-22GV has only 100% power level.
