– 132 –
In low speed rotation mode (PWM range), as shown in Fig. 6-2, 0-5V chopper signal is output from microcomputer for each phase.
Signal output
from microcomputer is output to IC1 and is inverted by active Lo to become 0-17V chopper signal; it is then applied to each pha
se transistor gate
to drive.
In high speed rotation mode (PWM range), as shown in Fig. 6-3, 0-5V drive signal is output from microcomputer for each phase (w
ith no chopper
because of full duty). Signal output from microcomputer is input to IC1 and is inverted by active Lo to become 0-17V drive sig
nal; it is then applied
to each phase transistor gate to drive.
6. Drive Circuit
Fig. 6-1 shows drive circuit.
U phase, V phase and W phase have the same circuit composition.
Fig. 6-1
B
COMPRESSOR MOTOR
MAIN P.W.B.
B
IC1
HIC
HIC
SPM2
R501
R512
R511
R510
R59
R508
R507
R411
R502
R503
R504
R526
R525
R524
R523
R522
R521
R536
R535
R534
R533
R532
R531
R505
Q506
Q505
Q504
Q503
Q502
Q501
V
d
N1
P2
R506
B
A
0V
17V
R24
B
B
B
12
14
15
16
17
18
19
8
5
3
3
4
5
6
7
8
8
2
5
6
1
3
4
7
6
5
4
3
45
44
43
42
41
40
6
10
MICON
17V
0V
17V
0V
17V
0V
17V
0V
Fig. 6-3
Fig. 6-2
< In Low speed >
<
In high speed >
Drive signal at
Drive signal at
Drive signal at
Drive signal at