Hitachi RAS-25WX8 - Page 74

– 73 –
R301
5V
R305
C302
64
1
2
3
4
5
0
010203040
3. Room Temperature Thermistor Circuit
A room temperature thermistor circuit is shown in Fig. 3-1.
According to room temperature, the voltage of point becomes as it is shown in Fig.3-2.
Microcomputer
Room Temperature
Thermistor
Voltage of point
(V)
(ć)
Room temperature
Room
temperature input
Fig. 3-1
Fig. 3-2
?
A
0V
0V
5V
20
2
0
1
0
3
4
5
40
10 30-10
R302
C303
R306
63
4. Heat Exchanger Thermistor Circuit
Heat exchanger temperature is noticed inside the room
(1) Preheating
(2) Low-temperature defrosts at cooling"dehumidification operation time.
(3) Not working of reversing valve or detection of opening of heat exchange thermistor is controlled.
According to heat exchange temperature, the voltage of point becomes as it is shown in Fig. 4-2.
Heat exchanger
thermistor
Microcomputer
Heat exchanger
input
Fig. 4-1
Fig. 4-2
Voltage of point (V)
ć
Room temperature ( )
?
A