Boosting And Varying Dc Voltage Vd - Hitachi RAF-25NH4 Service Manual

(1) Boosting and varying DC voltage Vd

It boosts the DC voltage to the valve corresponds to the rotation speed with a detected DC voltage by the micro computer.
Its component is basically made of a boosting chopper circuit.
The current I is absorbed into the reactor for On time and discharged to the capacitor for Off time with high frequency
1
chopping. (I )
2
It 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).
Reactor
IC
Analog voltage
D-bus filter
Instructions voltage
(PWM output)
ACT element
+
Q1
I
1
I
DC voltage
234
P
Compressor
M
2