Sharp R-771(W)N - Page 9

OPERATION
SEQUENCE
JFF CONDITION
slosing
the
door
activates
the
primary
latch
switch
and
the
itop
switch.
MPORTANT:
Nhen
the
oven
door
is
closed,
the
contacts
COM-NC
if
the
monitor
switch
must
be
open.
When
the
micro-
yave
oven
is
plugged
ina
wall
outlet
(230V
/50Hz),
the
ine
voltage
is
supplied
to
the
noise
filter
and
the
:ontrol
unit.
Figure O-1 on page 32
.
The
oven
display
will
flash
"PRESS
STOP"
in
6
lan-
guage.
»,
Press
the
STOP
button.
The
oven
display
will
flash
"SELECT
LANGUAGE’
in
6
languages.
}. Select language as follows.
3-1.
Choose
desired
language
by
pressing
the
LAN-
GUAGE
button.
3-2.
Start
the
setting
by
pressing
the
START
button.
The
oven
display
will
flash
"SET
CLOCK"
in
se-
lected
language.
|, Set the clock as follows.
4-1.
Choose
the
12
hour
clock
or
the
24
hour
clock
by
pressing
the
CLOCK
setting
button.
4.2.
Setthe
hours
by
rotating
the
TIME/WEIGHT
knob.
4-8.
Change
from
hours
to
minutes
by
pressing
CLOCK
setting
button.
.
4-4,
Set
the
minutes
by
rotating
the
TIME/WEIGHT
knob.
4-5,
Start
the
clock
by
pressing
the
CLOCK
setting
button.
NOTE:
.
{f
you
do
not
want
to
set
the
clock,
press
the
STOP
button
once
after
Janguage
is
chosen."
:
"
will
appear
on
the
display.
When
the
operation
of
the
oven
is
finished,
"
:
"will
appear
on
the
display
instead
of
the
time
of
day.
_
The
oven
can
be
also
used
when
the
language
and/or
the
clock
is
not
set..
|
3.
When
the
oven
door
is
opened,
the
oven
lamp
comes
on at this time.
ICROWAVE
COOKING
CONDITION
JIGH COOKING
Enter
a
desired
cooking
time
by
turning
the
TIME/WEIGHT
(nob
and
start
the
oven
by
pressing
START
button.
ow
Function sequence Figure O-2 on page 33
CONNECTED
COMPONENTS
RELAY
Oven
lamp,
Turntable
motor
RY1
High
voltage
transformer
RY1+
Grill
heating
element
RY1+
Botiom
heating
element
RY
1+
Fan
motor,
RY5
tL
I
|.
The
line
voltage
is
supplied
to
the
primary
winding
of
the
high
voltage
transformer.
The
voltage
is
converted
to
about
3.3
volts
A.C.
output
on
the
filament
winding
and
high
voltage
of
approximately
2000
volts
A.C.
on
the
secondary
winding.
2,
The
filament
winding
voltage
(3.3
volts}
heats
the
magnetron
filament
and
the
high
voltage
(2000
volts)
is
sent
to
the
voltage
doubling
circuit,
where
it
is
doubled
to
negative
voltage
of
approximately
4000
volts
D.C..
3.
The
2450
MHz
microwave
energy
produced
in
the
magnetron
generates
a
wave
length
of
12.24
cm.
This
energy
is
channelled
through
the
waveguide
(transport
channel)
into
the
oven
cavity,
where
the
food
is
placed
to
be
cooked.
.
4,
When
the
cooking
time
is
up,
a
signal
tone
is
heard
and
ihe
relays
RY1_
+
RY2
+
RY5
go
back
to
their
home
position.
The
circuits
to
the
oven
lamp,
high
voltage
transformer,
fan
motor
and
turntable
motor
are
cut
off.
5.
When
the
oven
door
is
opened
during
a
cooking
cycle,
the
switches
come
to
the
following
condition.
.
witch
ontact
ondition
During
Oven
Door
Cookin
Open(No
cooking)
Primary
latch
Switch
COM-NO
Closed
Opened
Stop
switch
COM-NO
Closed
Opened
Monitor
Switch
COM-NO
Closed
Opened
COM-NC
Opened
Closed
The
circuit
to
the
high
voltage
transformer,
fan
motor
and
turntable
motor
are
cut
off
when
the
primary
latch
switch
and
stop
switch
are
made
open.
The
oven
lamp
remains
on
even
if
the
oven
door
is
opened
after
the
cooking
cycle
has
been
interrupted,
because
the
relay
RY1
stay
closed.
Shown
in
the
display
is
remaining
time.
6. MONITOR SWITCH CIRCUIT
The
monitor
switch
SW3
is
mechanically
controlled
by
the
oven
door,
and
monitors
the
operation
of
the
primary
latch
switch
SW14.
6-1.
When
the
oven
door
is
opened
during
or
after
the
cycle
of
a
cooking
program,
the
primary
latch
switch
SW1
and
stop
switch
SW2
must
open
their
contacts
first.
After
that
the
contacts
(COM-NC)
of
the
monitor
switch
SW3
can
be
closed.
6-2.
When
the
oven
door
is
closed,
the
contacts
(COM-
NC)
of
the
monitor
switch
SW3
must
be
opened.
After
that
the
contacts
of
the
primary
latch
switch
SW1
and
the
stop
switch
SW2
are
closed.
6-3.
When
the
oven
door
is
opened
and
the
contacts
of
the
primary
latch
switch
SW1
remain
closed,
the
fuse
F2
F8A
will
blow,
because
the
monitor
switch
is
closed
and
a
short
circuit
is
caused.
MEDIUM
HIGH,
MEDIUM,
MEDIUM
LOW,
LOW
COOKING
|
When
the
microwave
oven
is
preset
for
variable
cooking
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.
42 sec, ON
SETTING 100% EINE Approx. 100%
24 sec. ON 6B sec, OFF
70%
Approx,
70%
1B sec. ON 44 sec. OFF
50% Approx. 50%
12 sec, ON 20 sec, OFF
30% Approx. 30%
6 sec. ON 26 sec, OFF
10% Approx. 10%
Note:
The
On/Offtime
ratio
does
not
exactly
correspond
to
the
percentage
of
microwave
power,
because
approx.
3
seconds
are
needed
for
heating
up
the
magnetron
filament.
R-771 - 9