– 79 –
6. Rotor magnetic pole position detection circuit
A
B
C
D
E
18
19
20
Outdoor microcomputer
C605
+5V
0V
HIC
0V
+12V
W
V
U
C608
System power module
DC brushless
motor for compressor
R604
R605
R606
R607
R601
R602
R603
R604
R603
R602
R608
C503
C502
C501
R611
R610
R609
0V
C606
0V
C607
0V
36
33 34
35
47
Fig. 6-1 Rotor magnetic pole position detection circuit and voltage waveform at each point
E
D
C
A
No power
supplied
Upper arm
ON
No power
supplied
No power
supplied
Lower arm
ON
60
120
60
120
Induced voltage
Comparing process
60
Vd 150 ~ 330
Spike voltage
U phase
terminal voltage
Drive signal
Pole position
detection signal
(B) reference
voltage (1/2Vd)
Detection point
W+
W+
U+
U+
U—
V—
V—
W—
V+
To detect U phase, voltage at point
C
is produced by driving motor induced voltage signal (voltage at point
A
) and
1/2 voltage of Vd (voltage at point
B
), and comparing with comparator.
For V phase and W phase, voltage at point
D
and voltage at point
E
are produced in the same way as above. Voltage
at point
C
is taken into indoor unit microcomputer, switching timing to U
+
transistor from W
+
transistor is produced by
delaying 30
°
from rise waveform, ignoring spike voltage. In addition, switching timing to U-transistor from W-transistor is
produced by delaying 30
°
from fall waveform.
For V phase and W phase, in the same way as above, drive signals are produced from voltages at point
D
and point
E
. Phases are shifted by 120
°
and 240
°
, respectively, comparing with U phase.
Summary of Contents for RAC-65NH5
Page 36: ...CIRCUIT DIAGRAM 37 ...
Page 37: ...CIRCUIT DIAGRAM MODEL RAC 65NH5 39 ...
Page 87: ... 99 SELF DIAGNOSIS LIGHTING MODE ...
Page 89: ... 101 2 Outdoor unit does not operate but receives remote infrared signal ...
Page 91: ... 103 6 Check the main P W B power circuit ...
Page 92: ... 104 CHECKING THE REMOTE CONTROLLER ...
Page 97: ... 109 ...
Page 107: ...HITACHI PM NO 0000E Printed in Malaysia RAK 65NH5 RAC 65NH5 ...