Hitachi RAF-25NH5 Instructions De Service page 280

(1) Boosting and varying DC voltage Vd
t boosts the DC voltage to the valve corresponds to the rotation speed with a detected DC voltage by the micro computer.
ts component is basically made of a boosting chopper circuit.
The current is absorbed into the reactor for On time and discharged to the capacitor for Off time with high frequency
1
chopping. ( )
2
t controls a chopper duty of Q1 so that a current be absorbed into the reactor and a current be consumed by the inverter are
balanced. At high loading, DC voltage is boosted as many duties (absorbing current much).
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ACT element
Reactor
C
Analog voltage
D-bus filter
nstructions voltage
(PWM output)
- 310 -
Q1 +
Ð
1
2
DC voltage
P
Compressor
M