Service Manual, 2016-12
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10.2Door trip test circuit(None)
10.3Temperature test circuit
It’s conducted by the sensor, making use of the characteristics that resistance value reduces as the
temperature increases, and the thermistor that has temperature coefficient of resistance in medium
temperature.
The characteristic that resistance value reduces as the temperature increases is deemed to have
negative slope or negative temperature coefficient (NTC), and such thermistor is called as NTC
thermistor. The resistance value changes sensitively with temperature and typically changes 7% ~
3% per degree centigrade. Sensor used in the refrigerator is NTC thermistor.
There is following computing formula for the sensor:
Sampling voltage / reference voltage = R1 / (RNTC + R1)
AD value / reference AD value = R1 / (RNTC + R1)
The reference voltage is 5V, RNTC is the resistance value of the sensor, R1 is R31\R32\R33 in
schematic diagram that is 5.1K
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