Hitachi RAK-18PSPA - Block Diagram

INDOOR UNIT
FM
Buzzer circuit
Indicating lamp
Operation.
Timer.
Auto sweep motor 1
M
Indoor microcomputer (AX-12C720)
Indoor DC fan motor
Indoor / Outdoor
interface circuit
Heat exchanger
thermistor
Room temperature
thermistor
Wireless receive
circuit
DC fan motor drive
circuit
Microcomputer clock
circuit
Initial setting circuit
Reset circuit
Temporary switch
Wireless remote
control
C
D
C
D
Outdoor microcomputer (AX-12C820)
OUTDOOR UNIT
POWER RELAY
Inrush current
Protection circuit
HARMONICS
IMPROVEMENT
CIRCUIT
IPM
Rotor magnetic
pole position
detection circuit
lp
ld
ls
Overheat thermistor
Defrost thermistor
Outdoor temperature thermistor
Indoor/Outdoor
interface circuit
Reversing valve coil
Power circuit
Reset
circuit
Outdoor DC fan motor
RECTIFIER
DC compressor
motor
Relay drive circuit
Electric expansion valve
Reversing valve
control circuit
MODEL
RAC-18/ 25/ 35WSPA
RAK-18/ 25/ 35PSPA
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