Samsung SR-S22DTC - Sensor and Switch Sensing Circuits

8-4) Door S/W Sensing Circuit
Terminal Voltage MICO’?
DOOR CLOSE | 5V (HIGH:
DOOR OPEN OV (LOWI
DOOR CLOSE | OV (LOW!
R-Room = ee
DOOR OPEN 5V (HIGH!
For
door
open
sensing
of
F
room,
®
of
CN30
is
connected
to
the
ground.
For
@,
Vec(DC
5V)
is
supplied
through
resistance
R404(4.7K),
and
“LOW”
(OV)/"
HIGH(5V)
is
applied
to
MICOM
by
open/close
of
the
F
room
door
so
that
it
can
sense
open/close
of
the
F
room
door.
For
door
open
sensing
of
R
room,
©
of
CN30
is
connected
to
the
ground.
For
©,
Vec(DC
5V)
is
supplied
through
resistance
R403(4.7K0),
and
“LOW”
(OV)/”
HIGH(5V)
is
applied
to
MICOM
by
open/close
of
the
R
room
door
so
that
it
can
sense
open/close
of
the
R
room
door.
At
this
time,
if
there
is
any
defect
at
the
door
S/W,
the
corresponding
fan
inside
the
Refrigerator
does
not
work
or
alarming
function
works.
Therefore,
the
door
S/W
must
be
checked
in
case
of
A/S.
That
is,
if
door
opens,
the
corresponding
fan
inside
the
Refrigerator
stops
without
fail.
When
connection
point
of
S/W
has
defect,
MICOM
judges
that
door
is
open
so
that
it
stops
the
fan
though
the
door
is
closed.
8-5)
Temperature
Sensing
Circuit
Part
)
pee) ee
FSENSOR
*-CVMS
$
=
a
Wi
TS
MICOM
terminal
Voltage
|
FDEF
SENSOR
-eap~101
eS
WwW
Toei
PIX.
=56
(F-SENSOR)
iow
!
marr
eee
se
:
[PI
#37
(F-DEF-SENSOA
ly
|
es
le
ter
7
.
PIN.
=58
(R-SENSOR)
shanti
=
he
:
PIN
=9
(R-DEF-SENSOR)
i
pe
aaa
~
Weige
Ph
=40
(ExTSENSOR)
ie
Sensor
uses
thermistor
which
has
temperature
coefficient
of
negative
resistance.
When
temperature
rises,
resistance
value
gets
smaller,
and
when
temperature
falls,
resistance
value
gets
larger.
R306~R310,
C301~C3085
are
parts
for
noise
prevention,
which
are
not
related
to
temperature
sensing
characteristic.
In
case
of
F-SENSOR,
if
setup
voltage
inputted
to
MICOM
Referred
to
as
Vf,
Vf=
(Rth*Vcc)/(R303+Rth).
Here,
Rth
is
resistance
value
of
thermistor
corresponding
to
temperature.
See
conversion
table
of
“Refer
6”
of
this
manual
on
resistance
and
voltage
of
sensor
about
temperature
for
Reference.
As
terminal
voltage
of
MICOM
corresponding
to
temperature
is
also
designated,
Refer
to
it
at
A/S
time.