
– 134 –
Fig. 7-1 shows the microcomputer and its peripheral circuits, Table 7-1, the basic operation of each circuit block,
and Fig. 7-2, the system configuration.
Table 7-1
Circuit block
Basic operation
Peak current
cutoff circuit
Trip signal
synthesis circuit
Set value circuit
Reset circuit
Voltage amplifier
circuit
Detects DC current flowing power module and during overcurrent (instantaneous value) flows,
stops upper/lower arm drive circuits and also produces IP signal by which drive signal output is
stopped.
Compares voltage detected, amplified and input to HIC with set voltage value in microcomputer,
and controls overload when set value exceeds input voltage.
Voltage-amplifies DC current level detected by the detection resistor and inputs this to
microcomputer, Internal or external overload is judged in microcomputer.
Modulates chopper signal to drive signal and stops according to presence/absence of IP signal or
reset signal.
Produces reset voltage.
7. HIC and Peripheral Circuits
+
+
+
+
+
A
B
CT1
0V
0V 0V
0V
0V
0V
12V
12V
0V
0V
0V
0V
0V
R41
IC1
OC
F
Is
Id
Vd
AX-8T11
MAIN P.W.B.
CN14
SPM2-HIC
SPM2
CN13
IC1
0V
0V
0V
2
3
1
IC5
0V
0V
0V
0V
5V
5V
Is
D104 R005
R221
JW10
C215
R289
R286
D106
R284
R292
R285
C226
C226
C204
C218
R222
R252
R288
R245
R24
Detection Resistor
N1
P2
DC Current
Direct Current
DC320-360V
R248
C205
IC4
R006
R116
C009
C105
C107
C217
D205
R247
R249
R253
R500
R42
C34
R43
C222
D204
C224
58
7
6
5
Ip
RESET
10
9
1
5
37
59
17
60
61
48
1
2
38
39
9
8
20
21
9
62
+
Fig. 7-1 Microcomputer (AX-8T11) and Peripheral Circuits