Hitachi RAC-50WX8 - Description of Main Circuit Operation

– 94 –
Fig. 1-1
Ｑ１１１
Ｒ１１４
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Ｑ１１２
Ｒ１１１
Ｒ１１５
Ｃ１１３
Ｃ１１６
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ＺＤ１１１
Ｒ１１６
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ＩＣ１１１
２
３
８
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１
Ｌ751
Ｒ631
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ＺＤ１３１
Ｍ
ＣＮ１０
１
２
３
４
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６
C131
C751
C621
Ｒ751
Ｍｏｔｏｒ
ＩｎｄｏｏｒＦａｎ
FM Rotation No.
Feedback
Indoor Fan
PWM Output
Ｃ１０５
＋
−
ＩＮＯＵＴ
ＧＮD
Ｄ１２１
−
０Ｖ
＋
ＺＤ１２１
Ｒ１１８
Ｃ１０３
３５Ｖ
ＩＣＰ２
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Ｌ１１１
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Ｄ１１１
Ｒ１１９
ＩＣＰ１
−
−
＋
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＋
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５Ｖ
Ｃ１２１
ＩＣ１２１
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ＸＡ−６Ｐ−Ｔｏｐ
14
40
Power to operate indoor unit (DC35V) is generated at the power supply in outdoor unit and it is sent to indoor unit
through the connecting cord C and D.
Then, DC 12V (12V line) is generated using DC/DC converter from the voltage sent from outdoor unit, as the
control voltage of 12V is required to drive the suction deflector motor and others.
Furthermore, 5V (5V line), which is necessary to drive the microcomputer and to control the fan motor, is generated
using three-terminal regulator IC121.
1. Power circuit
MODEL RAS-50WX8, RAS-D18EX3
DESCRIPTION OF MAIN CIRCUIT OPERATION
0V
35V