11-4) Door S/W Sensing Circuit; 11-5) Temperature Sensing Circuit - Samsung RS265 LAWP Service Manual

11. CIRCUIT DESCRIPTIONS

11-4) Door S/W Sensing Circuit

1) The terminals,
through the resistors, R404 and R403 for the freezer and the refrigerator door, respectively.
2) The micro-processor senses the door's open and close based on engaged voltages, "Low(0V)" and "High(5V),"
respectively.
Note) The door switch always should be checked when the evaporator fan is not running while the door is closed.

11-5) Temperature Sensing Circuit

1) A thermistor with a negative temperature coefficient (NTC) is used for a temperature sensor.
2) Resistors, R 306
3) For the F-sensor, the input voltage into the micro processor (MICOM), VF is calculated by (Rth x Vcc)/(R303+ Rth),
where Rth is a corresponding resistance to the thermistor's output (See Ref. 6 in Appendix).
and of the connector (CN30) are grounded, and DC5V (Vcc) is supplied to the terminals,
R310 and capacitors, C 301
Terminal Operation
DOOR CLOSE
Freezer
DOOR OPEN
DOOR CLOSE
Ref.
DOOR OPEN
# of terminal in MICOM
PIN #49 (F-SENSOR)
PIN #50 (F-DEF-SENSOR)
PIN #52 (R-SENSOR)
PIN #53 (R-DEF-SENSOR)
PIN #56 (EXT-SENSOR)
C 305 are used for a noise protection purpose.
77
Volt(state)
0V (LOW)
5V (HIGH)
0V (LOW)
5V (HIGH)
and
Remark
Micom
terminal
voltage may
change
according to
temp.