Hitachi RAS-25CNH2 - HIC and Peripheral Circuits

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8. HIC and Peripheral Circuits
● Fig. 8-1 shows the micro computer and its peripheral circuits, Table 8-1, the basic operations of each
circuit block, and Fig. 8-2, the system configuration.
Table 8-1
Circuit block
Basic operation
Peak current
cutoff circuit
Set value circuit
Voltage amplifier
circuit
Reset circuit
Trip signal
synthesis circuit
Detects DC current flowing power module and during overcurrent (instantaneous
value) flows, stops upper/lower arm drive circuits and also produces lp 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.
Produces reset voltage.
Modulates chopper signal to drive signal and stops according to presence/ab-
sence of lp signal or reset signal.
48
29
71
61
l
48
43
12
8
6
7
5
4
+
+
–
–
8
3
1
2
4
+
–
+
–
35
36
38
60
Is
D002
0V 0V
R038
C031
5V
5V
0V
To upper arm
drive circuit
0V
0V
0V
R24
0V
0V
0V
0V
12V
5V
5V
0V
0V
5V
5V
5V
12V
5V
OP1
COM2
1/2
C515
Detection
resistor
DC current
Power module
negative
terminal
To lower arm
drive circuit
–
Fig. 8-1 Micro computer (AX-8J01) and Peripheral Circuits
Chopper
Is
Id
Ip
POR
RESET
HIC
Outdoor micro
computer
(AX-8J01)