Hitachi RAS-25QH1 Technische Information Seite 171

9. HIC and Peripheral Circuits
@ Fig. 9-1 shows the micro computer and its peripheral circuits, Table 9-1, the basic operations of each
circuit block, and Fig. 9-2, the system configuration.
5V
12V
CHOP—HIC
)
ZD401A
449A Outdoor micro
computer (AX-8H20)
4s) RESET
ov
Power module negative
© terminal
@9 Power on reset
DC current
R463A
(7) Peak current cut off
Detection
resistor
ov 60 Id
a0
ee nei zo4oed
m CSO1A O, RA55A
ov
ov
To upper arm drive circuit aie!
R457A | (1) Chopper
~~ Qa05A
ov
Fig. 9-1 Micro computer (AX-8H20) and Peripheral Circuits
Table 9-1
Circuit block , Basic operation
2 ee
Detects the DC current flowing to the power module, and if overcurrent
Peak current cut off circuit | (instantaneous value) flows, this creates an Ip signal which stops the upper /
lower arm drive circuits and also stops the micro computer.
— Fr
Reset circuit Creates reset voltage.
Amplifies the DC current level detected by the detection resistor and transfers
Voltage amp. circuit it to the micro computer. {t determines whether the overload judgement is
| performed internally or externally.
Trip signal synthesis circuit / Lets the drive signal, modulate the chopper signal or stops
Trip signal synthesis circuit | the drive signal according to the presence or absence of the Ip or reset signal.
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